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<h1><a href="../gb/index.htm"><font size="2" face="Verdana">Eino |
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Uikkanen's homepage</font></a><font size="2" face="Verdana"> > |
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</font><a href="ficoords.htm"><font size="2" face="Verdana">Finnish |
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coordinate systems</font></a><font size="2" face="Verdana"> - |
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updated <!--webbot bot="Timestamp" startspan s-type="EDITED" |
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s-format="%d.%m.%Y" -->17.01.2013<!--webbot bot="Timestamp" |
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i-checksum="12478" endspan --></font></h1> |
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<hr noshade color="#808080"> |
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<h1><font size="2" face="Verdana">Finnish horizontal coordinate |
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systems</font></h1> |
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<blockquote> |
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<p><font size="2" face="Verdana">This article is a brief |
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description of the Finnish horizontal coordinate systems. The |
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list of the coordinate systems below in table 1.</font></p> |
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<table border="6"> |
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<tr> |
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<td colspan="5"><font size="2" face="Verdana"><strong>Table |
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1, Finnish horizontal coordinate systems</strong></font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana"><strong>ID</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Name in |
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Finnish</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Name in |
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English</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Used in map |
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production</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Comment</strong></font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">VVJ</font></td> |
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<td><font size="2" face="Verdana">Helsingin |
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j‰rjestelm‰</font></td> |
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<td><font size="2" face="Verdana">Helsinki system</font></td> |
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<td><font size="2" face="Verdana">-1970</font></td> |
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<td><font size="2" face="Verdana">Still used in some |
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cities</font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">ED50 (National)</font></td> |
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<td><font size="2" face="Verdana">European Datum 1950 |
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</font></td> |
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<td><font size="2" face="Verdana">European Datum 1950 |
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</font></td> |
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<td><font size="2" face="Verdana">Never</font></td> |
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<td><font size="2" face="Verdana">(National) = |
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national adjustment 1966</font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">KKJ</font></td> |
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<td><font size="2" face="Verdana">Kartastokoordinaattij‰rjestelm‰</font></td> |
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<td><font size="2" face="Verdana">Finnish National |
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Coordinate System</font></td> |
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<td><font size="2" face="Verdana">1970-2005</font></td> |
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<td><font size="2" face="Verdana">Based on ED50</font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">EUREF-FIN</font></td> |
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<td><font size="2" face="Verdana">EUREF-FIN</font></td> |
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<td><font size="2" face="Verdana">EUREF-FIN</font></td> |
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<td><font size="2" face="Verdana">2003- Nautical |
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charts, 2005- Topographic maps</font></td> |
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<td><font size="2" face="Verdana">ETRS89 realization |
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in Finland</font></td> |
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</tr> |
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</table> |
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</blockquote> |
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<blockquote> |
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<p><font size="2" face="Verdana">Finnish version of this |
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article can be found from: </font><a |
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href="../geodocs/kkjgps.htm"><font size="2" face="Verdana">Suomalaiset |
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koordinaatistot</font></a></p> |
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<p><font size="2" face="Verdana">If you have any comments, |
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questions or suggestions regarding this article, please don't |
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hesitate to contact me: </font><a |
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href="mailto:eino.uikkanen@iki.fi"><font size="2" |
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face="Verdana">eino.uikkanen@iki.fi</font></a></p> |
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</blockquote> |
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<h1><font size="2" face="Verdana"><strong>VVJ, Helsingin |
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j‰rjestelm‰, Helsinki system, -1970</strong></font></h1> |
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<blockquote> |
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<p><font size="2" face="Verdana">VVJ, Helsinki system, also |
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known in Finnish as 'Vanha valtion j‰rjestelm‰', is the |
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predecessor of the current KKJ coordinate system. The |
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transition from VVJ to KKJ started in 1970, but VVJ is still |
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in use in some cities.</font></p> |
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<p><font size="2" face="Verdana">KKJ is not based on VVJ, but |
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KKJ was defined so, that it optimally fits to it's |
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predecessor VVJ. Therefore VVJ coordinates can be handled as |
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if they were KKJ coordinates, noting however following |
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differences in values and representation of VVJ- and KKJ-coordinates:</font></p> |
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<ul> |
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<li><font size="2" face="Verdana">The difference between |
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VVJ and KKJ coordinates is 2 meters on average, the |
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maximum difference being appr. 10 meters. </font></li> |
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<li><font size="2" face="Verdana">VVJ y-coordinate is |
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represented without the preceding zone number, but |
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possibly preceded by central meridian value, e.g. if |
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KKJ y-coordinate is 3511666 then VVJ y-coordinate |
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represented as 511666 or 27∞511666</font></li> |
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<li><font size="2" face="Verdana">The VVJ coordinates are |
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often represented without thousands or even hundreds |
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of kilometers in the coordinate value.</font></li> |
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</ul> |
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</blockquote> |
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<h1><font size="2" face="Verdana">ED50 (National), European Datum |
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1950, Finnish National Adjustment 1966</font></h1> |
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<blockquote> |
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<p><font size="2" face="Verdana">In Finland the European |
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Datum 1950 (ED50) is based on the National Adjustment of the |
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first order triangulation network in 1966, in which the |
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initial coordinates were taken from the European adjustment (Korhonen, |
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1967). The result of this adjustment, national ED50, is never |
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used for mapping purposes directly. The national ED50 is |
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however important, because it is the base of the Finnish |
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National Coordinate System KKJ.</font></p> |
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</blockquote> |
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<h1><font size="2" face="Verdana">KKJ, Finnish National |
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Coordinate System, 1970 - 2003/2005</font></h1> |
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<blockquote> |
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<p><font size="2" face="Verdana">KKJ is derived from the |
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Finnish national adjustment (1966) of the ED50 (European |
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Datum 1950) coordinate system by shifting and rotating ED50 |
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plane coordinates so, that they optimally fit to KKJ's |
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predecessor VVJ, Helsinki System.</font></p> |
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<p><font size="2" face="Verdana">KKJ-coordinates can be |
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presented in geographical (latitude, longitude) or in |
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rectangular grid-coordinates (northing, easting). Very often |
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simple name KKJ without reference to the coordinate type is |
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used to refer to rectangular grid-coordinates. In fact, it's |
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quite a common misunderstanding, that KKJ means only the grid-coordinates. |
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Because KKJ is 2D-coordinate system, it does not contain any |
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definition of the height system. If, however, the height of a |
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point is given in connection with the horizontal coordinates, |
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it is always orthometric height in the national height system |
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(e.g. N60).</font></p> |
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<p><font size="2" face="Verdana">The reference ellipsoid used |
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with KKJ is International 1924 ellipsoid, also known as |
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Hayford ellipsoid. The parameters of this ellipsoid are |
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represented in table 2. Since the parameters of the reference |
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ellipsoids are in often expressed as delta values between WGS84 |
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and the appropriate ellipsoid, also delta values (DA, DF) are |
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represented in the table.</font></p> |
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<table border="6"> |
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<tr> |
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<td colspan="6"><font size="2" face="Verdana"><strong>Table |
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2, International 1924 and WGS84 ellipsoids</strong></font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana"><strong>Parameter</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Description</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Unit</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>WGS84</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>International |
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1924</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>WGS84-International |
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1924</strong></font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">A, DA</font></td> |
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<td><font size="2" face="Verdana">Semi major axis</font></td> |
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<td><font size="2" face="Verdana">meter</font></td> |
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<td><font size="2" face="Verdana">6378137</font></td> |
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<td><font size="2" face="Verdana">6378388.0</font></td> |
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<td><font size="2" face="Verdana">-251</font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">F, DF</font></td> |
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<td><font size="2" face="Verdana">Flattening</font></td> |
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<td> </td> |
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<td><font size="2" face="Verdana">1/298.257223563</font></td> |
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<td><font size="2" face="Verdana">1/297</font></td> |
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<td><font size="2" face="Verdana">-0.1419270</font></td> |
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</tr> |
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</table> |
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<p><font size="2" face="Verdana">Gauss-Kr¸ger projection |
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formula is used to convert between KKJ-geographical and KKJ-grid-coordinates. |
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KKJ-grid consists of six zones, each 3 degrees wide. Very |
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often only zones 1-4 are represented, because these zones |
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almost cover the entire Finland. This grid system with six 3 |
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degrees wide zones is called 'Basic Coordinate System', in |
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Finnish 'Peruskoordinaatisto'. Parameters for zone 3 are also |
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used countrywide and is then called 'Uniform Coordinate |
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System', in Finnish 'Yhten‰iskoordinaatisto' or YKJ. In |
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topographic maps the Basic Coordinate Systems grid-lines are |
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printed black and Uniform Coordinate Systems grid-lines are |
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printed red.</font></p> |
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<table border="6"> |
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<tr> |
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<td colspan="7"><font size="2" face="Verdana"><strong>Table |
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3, KKJ Basic Coordinate System, KKJ |
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peruskoordinaatisto</strong></font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana"><strong>Projection</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Ellipsoid</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Zone</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Central |
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Meridian</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>False |
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Easting</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Scale |
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factor at Central Meridian</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Zone width</strong></font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">KKJ</font></td> |
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<td><font size="2" face="Verdana">International 1924</font></td> |
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<td><font size="2" face="Verdana">0</font></td> |
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<td><font size="2" face="Verdana">18</font></td> |
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<td><font size="2" face="Verdana">500000</font></td> |
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<td><font size="2" face="Verdana">1.000</font></td> |
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<td><font size="2" face="Verdana">3</font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">KKJ</font></td> |
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<td><font size="2" face="Verdana">International 1924</font></td> |
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<td><font size="2" face="Verdana">1</font></td> |
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<td><font size="2" face="Verdana">21</font></td> |
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<td><font size="2" face="Verdana">1500000</font></td> |
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<td><font size="2" face="Verdana">1.000</font></td> |
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<td><font size="2" face="Verdana">3</font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">KKJ</font></td> |
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<td><font size="2" face="Verdana">International 1924</font></td> |
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<td><font size="2" face="Verdana">2</font></td> |
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<td><font size="2" face="Verdana">24</font></td> |
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<td><font size="2" face="Verdana">2500000</font></td> |
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<td><font size="2" face="Verdana">1.000</font></td> |
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<td><font size="2" face="Verdana">3</font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">KKJ</font></td> |
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<td><font size="2" face="Verdana">International 1924</font></td> |
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<td><font size="2" face="Verdana">3</font></td> |
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<td><font size="2" face="Verdana">27</font></td> |
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<td><font size="2" face="Verdana">3500000</font></td> |
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<td><font size="2" face="Verdana">1.000</font></td> |
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<td><font size="2" face="Verdana">3</font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">KKJ</font></td> |
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<td><font size="2" face="Verdana">International 1924</font></td> |
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<td><font size="2" face="Verdana">4</font></td> |
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<td><font size="2" face="Verdana">30</font></td> |
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<td><font size="2" face="Verdana">4500000</font></td> |
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<td><font size="2" face="Verdana">1.000</font></td> |
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<td><font size="2" face="Verdana">3</font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">KKJ</font></td> |
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<td><font size="2" face="Verdana">International 1924</font></td> |
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<td><font size="2" face="Verdana">5</font></td> |
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<td><font size="2" face="Verdana">33</font></td> |
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<td><font size="2" face="Verdana">5500000</font></td> |
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<td><font size="2" face="Verdana">1.000</font></td> |
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<td><font size="2" face="Verdana">3</font></td> |
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</tr> |
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</table> |
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<p> </p> |
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<table border="6"> |
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<tr> |
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<td colspan="7"><font size="2" face="Verdana"><strong>Table |
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4, KKJ Uniform Coordinate System, KKJ |
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yhten‰iskoordinaatisto YKJ</strong></font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana"><strong>Projection</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Ellipsoid</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Zone</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Central |
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Meridian</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>False |
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Easting</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Scale |
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factor at Central Meridian</strong></font></td> |
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<td><font size="2" face="Verdana"><strong>Zone width</strong></font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana">YKJ</font></td> |
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<td><font size="2" face="Verdana">International 1924</font></td> |
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<td><font size="2" face="Verdana">3</font></td> |
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<td><font size="2" face="Verdana">27</font></td> |
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<td><font size="2" face="Verdana">3500000</font></td> |
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<td><font size="2" face="Verdana">1.000</font></td> |
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<td><font size="2" face="Verdana">Country wide</font></td> |
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</tr> |
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</table> |
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<p><font size="2" face="Verdana">An easy way of thinking of |
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how KKJ-grid-coordinates are derived is as follows:</font></p> |
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</blockquote> |
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|
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<blockquote> |
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<ol> |
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<li><font size="2" face="Verdana">Go from the point to |
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the central meridian along the shortest way - the |
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length of the trip is the starting value for the y-coordinate. |
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On the western side of the central meridian this |
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value is negative and on the eastern side positive. E.g. |
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y=45107.</font></li> |
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<li><font size="2" face="Verdana">Continue from this |
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point to the equator along the central meridian - the |
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length of the trip is the value of the x-coordinate. |
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E.g. x=6717563.</font></li> |
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<li><font size="2" face="Verdana">Add 500000 meters to |
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the value of y-coordinate to make all y-coordinate |
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values positive. This value is called False Easting. |
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E.g. y=545107.</font></li> |
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<li><font size="2" face="Verdana">Put the number of the |
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zone in front of the y-coordinate. Now the value of |
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the y-coordinate tells also the zone number and |
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coordinate values of different zones are easy to |
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distinguish. E.g. y=2545107.</font></li> |
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<li><font size="2" face="Verdana">The final values of |
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grid-coordinates are: x=6717563 and y=2545107</font></li> |
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</ol> |
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</blockquote> |
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|
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<blockquote> |
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<p><font size="2" face="Verdana">Points 3 and 4 are normally |
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covered with one parameter, which is called False Easting. In |
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the example above the False Easting would then be 2500000 |
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meters (500000 meters + 2 in front of the coordinate-value).</font></p> |
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<p><font size="2" face="Verdana">Below sample values of |
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different coordinate types: </font></p> |
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<table border="6"> |
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<tr> |
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<td colspan="3"><font size="2" face="Verdana"><strong>Table |
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5, Sample coordinate values</strong></font></td> |
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</tr> |
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<tr> |
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<td><font size="2" face="Verdana"><strong>Coordinate |
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type</strong></font></td> |
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<td align="center"><font size="2" face="Verdana"><strong>Latitude</strong></font></td> |
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<td align="center"><font size="2" face="Verdana"><strong>Longitude</strong></font></td> |
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</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">WGS84 geographical</font></td> |
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<td><font size="2" face="Verdana">60.566077</font></td> |
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<td><font size="2" face="Verdana">24.819210</font></td> |
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</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">KKJ geographical</font></td> |
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<td><font size="2" face="Verdana">60.565894</font></td> |
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<td><font size="2" face="Verdana">24.822422</font></td> |
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</tr> |
|
<tr> |
|
<td align="center"> </td> |
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<td align="center"><font size="2" face="Verdana"><strong>x</strong></font></td> |
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<td align="center"><font size="2" face="Verdana"><strong>y</strong></font></td> |
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</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">KKJ-grid, zone 2</font></td> |
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<td><font size="2" face="Verdana">6717563</font></td> |
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<td><font size="2" face="Verdana">2545107</font></td> |
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</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">KKJ-grid, zone 3/Uniform</font></td> |
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<td><font size="2" face="Verdana">6719258</font></td> |
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<td><font size="2" face="Verdana">3380581</font></td> |
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</tr> |
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</table> |
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</blockquote> |
|
|
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<blockquote> |
|
<p><font size="2" face="Verdana"><strong>Conversion between |
|
ETRS89(WGS84) and KKJ - datum conversion</strong></font></p> |
|
</blockquote> |
|
|
|
<blockquote> |
|
<p><font size="2" face="Verdana">The best values for three |
|
and seven parameter similarity transformations from KKJ to |
|
ETRS89/WGS84 are described in the table 6. More accurate (than |
|
similarity transformation) transformation methods between |
|
EUREF-FIN(WGS84) and KKJ are described in </font><a |
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href="http://www.jhs-suositukset.fi/suomi/jhs154"><font |
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size="2" face="Verdana">Public Recommendation 154</font></a><font |
|
size="2" face="Verdana"> (JHS 154, JUHTA - Advisory Committee |
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on Information Management in Public Administration).</font></p> |
|
<p><font size="2" face="Verdana">The parameters for the seven |
|
parameter similarity transformation (column 1) are calculated |
|
by </font><a href="http://www.fgi.fi/index_eng.php"><font |
|
size="2" face="Verdana">Finnish Geodetic Institute</font></a><font |
|
size="2" face="Verdana"> (FGI) for KKJ-ETRS89 conversion |
|
using least square method and based on 90 points, for which |
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both ETRS89-coordinates measured by Finnish Geodetic |
|
Institute and KKJ-coordinates are known. Therefore these |
|
parameters give at least nearly as good result as a |
|
similarity transformation ever can give. Because of the |
|
distortion of both scale and orientation in the current KKJ-system, |
|
this similarity transformation still leaves residual errors |
|
of maximum two meters. </font></p> |
|
<p><font size="2" face="Verdana">The parameters for three |
|
parameter similarity transformations (columns 2-4) I have |
|
calculated myself using the 90 points used by Finnish |
|
Geodetic Institute to calculate KKJ-ERTS89- transformation |
|
parameters. This way the measurements made by Finnish |
|
Geodetic Institute made it possible to calculate new more |
|
accurate parameters for three parameter similarity |
|
transformations too. I made the calculations simply by |
|
minimizing the arithmetic averages of the errors in 3D-cartesian-coordinate |
|
values X, Y and Z. Then I rounded the values to the nearest |
|
integers, because I calculated these values mainly for use in |
|
handheld GPS-devices and most handheld GPS-devices accept |
|
only integer values for DX, DY and DZ. Parameters, which are |
|
calculated to be used anywhere in Finland, are listed in |
|
column 2. The parameters which I calculated to give the best |
|
fit in southern Finland (latitude <65 degrees) and |
|
northern Finland (latitude >65 degrees) are listed in |
|
columns 3 and 4.</font></p> |
|
<p><font size="2" face="Verdana">In column 5 (gray column) I |
|
have presented also the parameters, which are in use in many |
|
computer programs and most handheld GPS-devices, where the |
|
transformation between KKJ and WGS84 is predefined. These |
|
parameters are calculated by Jukka Varonen from Finnish |
|
Maritime Administration in 1989. These parameters were |
|
calculated for use in the sea area only (covering appr. |
|
Southern Finland), but are still well applicable for the |
|
entire Finland.</font></p> |
|
<p><font size="2" face="Verdana">Average and maximum errors |
|
for all parameter sets I have calculated myself. Error-values |
|
for the three parameter sets I have calculated for rounded |
|
values. N/B, that these error-values are average and maximum |
|
values of errors within selected sets of points. These sets |
|
of points represent the selected areas very well, but still, |
|
the error values represent errors within these sets of points |
|
only, not average and maximum errors in general.</font></p> |
|
<table border="6"> |
|
<tr> |
|
<td colspan="8"><font size="2" face="Verdana"><strong>Table |
|
6, Parameters for similarity transformation between |
|
KKJ and WGS84 (ETRF89) </strong></font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana"><strong>Parameter</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Description</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Unit</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>1</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>2</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>3</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>4</strong></font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana"><strong>5</strong></font></td> |
|
</tr> |
|
<tr> |
|
<td> </td> |
|
<td><font size="2" face="Verdana">Latitudes of the |
|
applied area</font></td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td><font size="2" face="Verdana"><65</font></td> |
|
<td><font size="2" face="Verdana">>65</font></td> |
|
<td bgcolor="#C0C0C0"> </td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">DX</font></td> |
|
<td><font size="2" face="Verdana">Shift along X-axis</font></td> |
|
<td><font size="2" face="Verdana">meter</font></td> |
|
<td><font size="2" face="Verdana">-96.062</font></td> |
|
<td><font size="2" face="Verdana">-75</font></td> |
|
<td><font size="2" face="Verdana">-74</font></td> |
|
<td><font size="2" face="Verdana">-76</font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">-78</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">DY</font></td> |
|
<td><font size="2" face="Verdana">Shift along Y-axis</font></td> |
|
<td><font size="2" face="Verdana">meter</font></td> |
|
<td><font size="2" face="Verdana">-82.428</font></td> |
|
<td><font size="2" face="Verdana">-230</font></td> |
|
<td><font size="2" face="Verdana">-229</font></td> |
|
<td><font size="2" face="Verdana">-232</font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">-231</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">DZ</font></td> |
|
<td><font size="2" face="Verdana">Shift along Z-axis</font></td> |
|
<td><font size="2" face="Verdana">meter</font></td> |
|
<td><font size="2" face="Verdana">-121.754</font></td> |
|
<td><font size="2" face="Verdana">-89</font></td> |
|
<td><font size="2" face="Verdana">-88</font></td> |
|
<td><font size="2" face="Verdana">-91</font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">-97</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">rx</font></td> |
|
<td><font size="2" face="Verdana">Rotation around X-axis</font></td> |
|
<td><font size="2" face="Verdana">second</font></td> |
|
<td><font size="2" face="Verdana">-4.801</font></td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td bgcolor="#C0C0C0"> </td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">ry</font></td> |
|
<td><font size="2" face="Verdana">Rotation around Y-axis</font></td> |
|
<td><font size="2" face="Verdana">second</font></td> |
|
<td><font size="2" face="Verdana">-0.345</font></td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td bgcolor="#C0C0C0"> </td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">rz</font></td> |
|
<td><font size="2" face="Verdana">Rotation around Z-axis</font></td> |
|
<td><font size="2" face="Verdana">second</font></td> |
|
<td><font size="2" face="Verdana">+1.376</font></td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td bgcolor="#C0C0C0"> </td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">m</font></td> |
|
<td><font size="2" face="Verdana">Scale factor = (scale-1)*10^6</font></td> |
|
<td> </td> |
|
<td><font size="2" face="Verdana">+1.496</font></td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td bgcolor="#C0C0C0"> </td> |
|
</tr> |
|
<tr> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td bgcolor="#C0C0C0"> </td> |
|
</tr> |
|
<tr> |
|
<td> </td> |
|
<td><font size="2" face="Verdana">Average error</font></td> |
|
<td><font size="2" face="Verdana">meter</font></td> |
|
<td><font size="2" face="Verdana">0.8</font></td> |
|
<td><font size="2" face="Verdana">1.6</font></td> |
|
<td><font size="2" face="Verdana">1.4</font></td> |
|
<td><font size="2" face="Verdana">0.8</font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">1.8</font></td> |
|
</tr> |
|
<tr> |
|
<td> </td> |
|
<td><font size="2" face="Verdana">Maximum error</font></td> |
|
<td><font size="2" face="Verdana">meter</font></td> |
|
<td><font size="2" face="Verdana">2</font></td> |
|
<td><font size="2" face="Verdana">3.3</font></td> |
|
<td><font size="2" face="Verdana">2.5</font></td> |
|
<td><font size="2" face="Verdana">1.8</font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">3.4</font></td> |
|
</tr> |
|
</table> |
|
<p><font size="2" face="Verdana">Before applying these |
|
parameters one should check, how his program or GPS-device |
|
expects the units of measures and signs of rotation angles (rotation |
|
directions) to be given. Below the formula, for which the |
|
parameters in this article are calculated. Most programs and |
|
GPS-devices use this formula, but there are exceptions.</font></p> |
|
<table border="6"> |
|
<tr> |
|
<td><font size="2" face="Verdana"><strong>Table 7, 3D-similarity |
|
transformation formula, for which the parameters are |
|
calculated</strong></font></td> |
|
</tr> |
|
<tr> |
|
<td><pre><font size="2"> |X2| |DX| | 1 Rz -Ry | |X1|</font></pre> |
|
<pre><font size="2"> |Y2| = |DY| + (1+m/10^6) * |-Rz 1 Rx | * |Y1|</font></pre> |
|
<pre><font size="2"> |Z2| |DZ| | Ry -Rx 1 | |Z1|</font></pre> |
|
</td> |
|
</tr> |
|
</table> |
|
</blockquote> |
|
|
|
<p> </p> |
|
|
|
<h1><font size="2" face="Verdana">EUREF-FIN, ETRS89 realization |
|
in Finland, 2003/2005-</font></h1> |
|
|
|
<blockquote> |
|
<p><font size="2" face="Verdana">Finland is in the middle of |
|
the transition period, during which the current national |
|
coordinate system KKJ will be replaced by pan-European |
|
coordinate system ETRS89.</font></p> |
|
<p><a href="http://www.fgi.fi/index_eng.php"><font size="2" |
|
face="Verdana">Finnish Geodetic Institute</font></a><font |
|
size="2" face="Verdana"> has created reference frame called |
|
EUREF-FIN, which is fixed to European-wide EUREF89 reference |
|
frame. EUREF89 is a realization of ETRS89. EUREF-FIN |
|
coincides with WGS84 at meter level (diff. 2012 appr.80 cm) |
|
and therefore for all mapping and charting purposes EUREF-FIN |
|
and WGS84 can be considered the same.</font></p> |
|
<p><font size="2" face="Verdana">The realization of the pan-European |
|
coordinate system ETRS89 in Finland (EUREF-FIN) is defined in |
|
the </font><a |
|
href="http://www.jhs-suositukset.fi/suomi/jhs153"><font |
|
size="2" face="Verdana">Public Recommendation 153</font></a><font |
|
size="2" face="Verdana"> (JHS 153, JUHTA - Advisory Committee |
|
on Information Management in Public Administration). In |
|
national mapping and spatial information services it is |
|
recommended to use ETRS89 (EUREF-FIN) instead of the current |
|
KKJ coordinate system.</font></p> |
|
<p><font size="2" face="Verdana">The map projections and |
|
plane coordinates used with EUREF-FIN as well as accurate |
|
datum transformation methods and parameters between EUREF-FIN |
|
and KKJ coordinates are defined in the </font><a |
|
href="http://www.jhs-suositukset.fi/suomi/jhs154"><font |
|
size="2" face="Verdana">Public Recommendation 154</font></a><font |
|
size="2" face="Verdana"> (JHS 154, JUHTA - Advisory Committee |
|
on Information Management in Public Administration).</font></p> |
|
<p><font size="2" face="Verdana">In country wide use it is |
|
recommended to use pan-European ETRS89-TMnn -projection (UTM, |
|
nn = zone number). In Finland projection ETRS-TM35 is used |
|
country wide and is therefore called ETRS-TM35FIN, where FIN |
|
is for the non-standard zone width.</font></p> |
|
<p><font size="2" face="Verdana">In local mapping and spatial |
|
information services it is possible to use Gauss-Kr¸ger -projection |
|
called ETRS-GKn, where n is the (closest) central meridian. </font></p> |
|
<p><font size="2" face="Verdana">Table 8 describes the |
|
projection parameters for the grid coordinates used in |
|
Finland. For comparison purposes also KKJ projection |
|
parameters are included. </font></p> |
|
<table border="6"> |
|
<tr> |
|
<td colspan="6"><font size="2" face="Verdana"><strong>Table |
|
8, Projection parameters for grid coordinates used in |
|
Finland</strong></font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana"><strong>Projection</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Ellipsoid</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Central |
|
Meridian</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>False |
|
Easting</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Scale |
|
factor at Central Meridian</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Zone width</strong></font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">ETRS-TM35FIN</font></td> |
|
<td><font size="2" face="Verdana">GRS80</font></td> |
|
<td><font size="2" face="Verdana">27</font></td> |
|
<td><font size="2" face="Verdana">500000 </font></td> |
|
<td><font size="2" face="Verdana">0.9996</font></td> |
|
<td><font size="2" face="Verdana">13</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">ETRS-TMn, n=34,35,36</font></td> |
|
<td><font size="2" face="Verdana">GRS80</font></td> |
|
<td><font size="2" face="Verdana">21,27,33</font></td> |
|
<td><font size="2" face="Verdana">500000</font></td> |
|
<td><font size="2" face="Verdana">0.9996</font></td> |
|
<td><font size="2" face="Verdana">6</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">ETRS-GK </font></td> |
|
<td><font size="2" face="Verdana">GRS80</font></td> |
|
<td><font size="2" face="Verdana">19,20,...,31</font></td> |
|
<td><font size="2" face="Verdana">n500000, n=19,20,...,31</font></td> |
|
<td><font size="2" face="Verdana">1.0000</font></td> |
|
<td><font size="2" face="Verdana">1</font></td> |
|
</tr> |
|
<tr> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">KKJ</font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">International |
|
1924</font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">18,21,24,27,30,33</font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">n500000, |
|
n=0,1,...,5</font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">1.0000</font></td> |
|
<td bgcolor="#C0C0C0"><font size="2" face="Verdana">3</font></td> |
|
</tr> |
|
</table> |
|
</blockquote> |
|
|
|
<blockquote> |
|
<p><font size="2" face="Verdana">GRS80 reference ellipsoid |
|
used in conversion between 3D X,Y,Z -coordinates and geodetic |
|
coordinates. The difference between GRS80 and WGS84 |
|
ellipsoids is so small, that it can be ignored in most |
|
applications. In table 9 however the parameters for both |
|
ellipsoids and comparison between parameters.</font></p> |
|
<table border="6"> |
|
<tr> |
|
<td colspan="6"><font size="2" face="Verdana"><strong>Table |
|
9, GRS80 and WGS84 ellipsoids</strong></font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana"><strong>Parameter</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Description</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Unit</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>WGS84</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>GRS80</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>WGS84-GRS80</strong></font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">A, DA</font></td> |
|
<td><font size="2" face="Verdana">Semimajor axis</font></td> |
|
<td><font size="2" face="Verdana">meter</font></td> |
|
<td><font size="2" face="Verdana">6378137</font></td> |
|
<td><font size="2" face="Verdana">6378137</font></td> |
|
<td><font size="2" face="Verdana">0</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">F, DF</font></td> |
|
<td><font size="2" face="Verdana">Flattening</font></td> |
|
<td> </td> |
|
<td><font size="2" face="Verdana">1/298.257223563</font></td> |
|
<td><font size="2" face="Verdana">1/298.257222101</font></td> |
|
<td><font size="2" face="Verdana">-0.000000164423..</font></td> |
|
</tr> |
|
</table> |
|
</blockquote> |
|
|
|
<blockquote> |
|
<p><font size="2" face="Verdana"><strong>New maps</strong></font></p> |
|
<p><font size="2" face="Verdana">Starting from 2003 have all |
|
new nautical charts been published in EUREF-FIN (appr. WGS 84). |
|
These new nautical charts apply international INT chart |
|
symbols. Because shallow waters are printed in blue according |
|
the INT symbols, the new nautical charts are called "blue |
|
nautical charts" while the old nautical charts are |
|
called "green nautical charts" based on the green |
|
color of the land areas. The transition period, during which |
|
the new and old nautical charts are used parallel, will be 4 |
|
to 5 years long.</font></p> |
|
<p><font size="2" face="Verdana">Starting from 2005 </font><a |
|
href="http://www.maanmittauslaitos.fi/"><font size="2" |
|
face="Verdana">National Land Survey of Finland</font></a><font |
|
size="2" face="Verdana"> produces new topographic maps in |
|
EUREF-FIN. The transition period, during which the new and |
|
old topographic maps are used parallel will be several years |
|
long. In the new maps ETRS-TM35FIN-grid is printed with black |
|
crosses, three UTM-grids TM34, TM35 and TM36 are printed in |
|
red and geographical coordinates are printed in blue. ETRS-GK-grids |
|
are not printed on basic maps.</font></p> |
|
</blockquote> |
|
|
|
<h1><font size="2" face="Verdana">Conversions between coordinate |
|
systems</font></h1> |
|
|
|
<blockquote> |
|
<h1><font size="2" face="Verdana">Using Finnish maps with GPS-devices |
|
and electronic maps</font></h1> |
|
</blockquote> |
|
|
|
<blockquote> |
|
<p><font size="2" face="Verdana">When Finnish maps are used |
|
with GPS-devices or mapping/navigation programs, the |
|
respective datum- and/or grid-parameters may need to be |
|
selected or set up according to the table 10. An empty cell |
|
means, that you can apply general default parameters; datum=WGS84/EUREF-FIN, |
|
ellipsoid=WGS84/GRS80 or close.</font></p> |
|
<table border="6"> |
|
<tr> |
|
<td colspan="6"><font size="2" face="Verdana"><strong>Table |
|
10, Datum- and grid-conversions needed with Finnish |
|
maps</strong></font></td> |
|
</tr> |
|
<tr> |
|
<td colspan="2"><font size="2" face="Verdana"><strong>Map |
|
type</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Coordinate |
|
type</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Datum |
|
conversion</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Ellipsoid</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Grid |
|
conversion</strong></font></td> |
|
</tr> |
|
<tr> |
|
<td rowspan="2" colspan="2"><font size="2" |
|
face="Verdana">Old topographic maps, KKJ, 1970-2005</font></td> |
|
<td><font size="2" face="Verdana">Geographic</font></td> |
|
<td><font size="2" face="Verdana">KKJ <> EUREF-FIN</font></td> |
|
<td><font size="2" face="Verdana">International 1924</font></td> |
|
<td> </td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">Grid</font></td> |
|
<td><font size="2" face="Verdana">KKJ <> EUREF-FIN</font></td> |
|
<td><font size="2" face="Verdana">International 1924</font></td> |
|
<td><font size="2" face="Verdana">KKJ1-KKJ5 / YKJ</font></td> |
|
</tr> |
|
<tr> |
|
<td colspan="2"><font size="2" face="Verdana">Old |
|
"green" nautical charts, KKJ, -2002</font></td> |
|
<td><font size="2" face="Verdana">Geographic</font></td> |
|
<td><font size="2" face="Verdana">KKJ <> EUREF-FIN</font></td> |
|
<td><font size="2" face="Verdana">International 1924</font></td> |
|
<td> </td> |
|
</tr> |
|
<tr> |
|
<td rowspan="2" colspan="2"><font size="2" |
|
face="Verdana">New topographic maps, EUREF-FIN, 2005-</font></td> |
|
<td><font size="2" face="Verdana">Geographic</font></td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">Grid</font></td> |
|
<td> </td> |
|
<td> </td> |
|
<td><font size="2" face="Verdana">ETRS-TM35FIN / ETRS-GK(n)</font></td> |
|
</tr> |
|
<tr> |
|
<td colspan="2"><font size="2" face="Verdana">New |
|
"blue" nautical charts, EUREF-FIN, 2003-</font></td> |
|
<td><font size="2" face="Verdana">Geographic</font></td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
</tr> |
|
</table> |
|
</blockquote> |
|
|
|
<blockquote> |
|
<p><font size="2" face="Verdana">A datum conversion between |
|
KKJ and WGS84/EUREF-FIN is predefined in many GPS-devices and |
|
electronic mapping programs. These predefined conversions |
|
include both 3D-similarity transformation (datum-conversion) |
|
conversion between 3D-cartesian coordinates and geographic |
|
coordinates (ellipsoidal conversion). The problem here is, |
|
that KKJ has many aliases in different GPS-devices; KKJ, KKJ3, |
|
KKJ27, Finnish Grid, Finnish Nautical Chart etc. </font></p> |
|
</blockquote> |
|
|
|
<blockquote> |
|
<p><font size="2" face="Verdana">In many GPS-devices the grid |
|
parameters for YKJ uniform coordinate system are predefined (but |
|
named KKJ, KKJ3, Finnish grid, seldom YKJ). The grid |
|
parameters for other KKJ zones (basic coordinate system) are |
|
very seldom predefined. If the KKJ-grid parameters are |
|
predefined, selecting KKJ-grid parameters selects normally |
|
automatically the KKJ-datum parameters too. </font></p> |
|
<p><font size="2" face="Verdana">It is also normally possible |
|
to enter the grid parameters as user defined parameters. In |
|
that case take the parameters from tables 3, 4 or 8. Please |
|
note, that Central Meridian is also called Longitude of |
|
Origin. The value for false northing is 0 in all cases (new |
|
and old grids).</font></p> |
|
<h1><font size="2" face="Verdana">Conversion flow, formulae |
|
and parameters</font></h1> |
|
<p><font size="2" face="Verdana">Table 11 describes the |
|
entire conversion flow from KKJ grid-coordinates to EUREF-FIN |
|
grid-coordinates with respective formulae and parameters. |
|
This conversion flow is quite general and hence applicable to |
|
many similar cases by substituting the parameters or |
|
projected coordinate formula with respective parameters or |
|
formula.</font></p> |
|
<table border="6"> |
|
<tr> |
|
<td colspan="6"><font size="2" face="Verdana"><strong>Table |
|
11, conversion flow KKJ-grid-coordinates > ETRS-based |
|
grid coordinates > KKJ-grid-coordinates </strong></font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana"><strong>From</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>To</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Conversion</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Formula</strong></font></td> |
|
<td><font size="2" face="Verdana"><strong>Parameters</strong></font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">KKJ grid-coordinates</font></td> |
|
<td><font size="2" face="Verdana">KKJ geographic</font></td> |
|
<td><font size="2" face="Verdana">Transverse Mercator |
|
projection (Gauss-Kr¸ger)</font></td> |
|
<td><a |
|
href="http://www.jhs-suositukset.fi/suomi/jhs154"><font |
|
size="2" face="Verdana">JHS154</font></a><font |
|
size="2" face="Verdana">, app. 1</font></td> |
|
<td><font size="2" face="Verdana">KKJ-grid-coordinates, |
|
table 3</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">KKJ geographic</font></td> |
|
<td><font size="2" face="Verdana">KKJ 3D-X,Y,Z-coordinates</font></td> |
|
<td><font size="2" face="Verdana">Geographic > 3D-X,Y,Z</font></td> |
|
<td><a |
|
href="http://www.jhs-suositukset.fi/suomi/jhs153"><font |
|
size="2" face="Verdana">JHS153</font></a><font |
|
size="2" face="Verdana">, 5.2</font></td> |
|
<td><font size="2" face="Verdana">Hayford ellipsoid, |
|
table 2</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">KKJ 3D-X,Y,Z-coordinates</font></td> |
|
<td><font size="2" face="Verdana">EUREF-FIN 3D-X,Y,Z-coordinates</font></td> |
|
<td><font size="2" face="Verdana">Datum-transformation, |
|
3D-similarity transformation</font></td> |
|
<td><font size="2" face="Verdana">table 7</font></td> |
|
<td><font size="2" face="Verdana">Table 6, column 1</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">EUREF-FIN 3D-X,Y,Z-coordinates</font></td> |
|
<td><font size="2" face="Verdana">EUREF-FIN |
|
geographic</font></td> |
|
<td><font size="2" face="Verdana">3D-X,Y,Z > |
|
geographic</font></td> |
|
<td><a |
|
href="http://www.jhs-suositukset.fi/suomi/jhs153"><font |
|
size="2" face="Verdana">JHS153</font></a><font |
|
size="2" face="Verdana">, 5.2</font></td> |
|
<td><font size="2" face="Verdana">GRS80 ellipsoid, |
|
table 9</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">EUREF-FIN |
|
geographic</font></td> |
|
<td><font size="2" face="Verdana">ETRS-based grid |
|
coordinates</font></td> |
|
<td><font size="2" face="Verdana">Transverse Mercator |
|
projection</font></td> |
|
<td><a |
|
href="http://www.jhs-suositukset.fi/suomi/jhs154"><font |
|
size="2" face="Verdana">JHS154</font></a><font |
|
size="2" face="Verdana">, app. 1</font></td> |
|
<td><font size="2" face="Verdana">ETRS-based grid |
|
coordinates, table 8</font></td> |
|
</tr> |
|
<tr> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
<td> </td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">ETRS-based grid |
|
coordinates</font></td> |
|
<td><font size="2" face="Verdana">EUREF-FIN |
|
geographic</font></td> |
|
<td><font size="2" face="Verdana">Transverse Mercator |
|
projection</font></td> |
|
<td><a |
|
href="http://www.jhs-suositukset.fi/suomi/jhs154"><font |
|
size="2" face="Verdana">JHS154</font></a><font |
|
size="2" face="Verdana">, app. 1</font></td> |
|
<td><font size="2" face="Verdana">ETRS-based grid |
|
coordinates, table 8</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">EUREF-FIN |
|
geographic</font></td> |
|
<td><font size="2" face="Verdana">EUREF-FIN 3D-X,Y,Z-coordinates</font></td> |
|
<td><font size="2" face="Verdana">Geographic > 3D-X,Y,Z</font></td> |
|
<td><a |
|
href="http://www.jhs-suositukset.fi/suomi/jhs153"><font |
|
size="2" face="Verdana">JHS153</font></a><font |
|
size="2" face="Verdana">, 5.2</font></td> |
|
<td><font size="2" face="Verdana">GRS80 ellipsoid, |
|
table 9</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">EUREF-FIN 3D-X,Y,Z-coordinates</font></td> |
|
<td><font size="2" face="Verdana">KKJ 3D-X,Y,Z-coordinates</font></td> |
|
<td><font size="2" face="Verdana">Datum-transformation, |
|
3D-similarity transformation</font></td> |
|
<td><font size="2" face="Verdana">table 7</font></td> |
|
<td><font size="2" face="Verdana">Table 6, column 1</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">KKJ 3D-X,Y,Z-coordinates</font></td> |
|
<td><font size="2" face="Verdana">KKJ geographic</font></td> |
|
<td><font size="2" face="Verdana">3D-X,Y,Z > |
|
geographic</font></td> |
|
<td><a |
|
href="http://www.jhs-suositukset.fi/suomi/jhs153"><font |
|
size="2" face="Verdana">JHS153</font></a><font |
|
size="2" face="Verdana">, 5.2</font></td> |
|
<td><font size="2" face="Verdana">Hayford ellipsoid, |
|
table 2</font></td> |
|
</tr> |
|
<tr> |
|
<td><font size="2" face="Verdana">KKJ geographic</font></td> |
|
<td><font size="2" face="Verdana">KKJ grid-coordinates</font></td> |
|
<td><font size="2" face="Verdana">Transverse Mercator |
|
projection (Gauss-Kr¸ger)</font></td> |
|
<td><a |
|
href="http://www.jhs-suositukset.fi/suomi/jhs154"><font |
|
size="2" face="Verdana">JHS154</font></a><font |
|
size="2" face="Verdana">, app. 1</font></td> |
|
<td><font size="2" face="Verdana">KKJ-grid-coordinates, |
|
table 3</font></td> |
|
</tr> |
|
</table> |
|
<p><font size="2" face="Verdana"><strong>Conversion services |
|
online</strong></font></p> |
|
<p><a href="http://www.fgi.fi/index_eng.php"><font size="2" |
|
face="Verdana">Finnish Geodetic Institute</font></a><font |
|
size="2" face="Verdana"> has created </font><a |
|
href="http://coordtrans.fgi.fi/index.jsp"><font size="2" |
|
face="Verdana">online conversion service</font></a><font |
|
size="2" face="Verdana"> for coordinate conversions between |
|
all coordinate reference systems used nationally in Finland.</font></p> |
|
<p><font size="2" face="Verdana"><strong>About the conversion |
|
accuracy</strong></font></p> |
|
<p><font size="2" face="Verdana">The conversions between the |
|
3D-Cartesian, geodetic and grid-coordinates very seldom cause |
|
considerable errors, but as explained above, due to the |
|
distortion in both scale and orientation in the current KKJ-system, |
|
the seven parameter similarity datum transformation with best |
|
parameters between KKJ and EUREF-FIN leaves residual errors |
|
of maximum two meters. Most handheld GPS devices and mapping |
|
and navigation programs use simpler three parameter |
|
similarity transformation, which leaves even greater residual |
|
errors (see table 6)</font></p> |
|
<p><font size="2" face="Verdana">It is however worth noticing, |
|
that the conversion errors are only one part of the total |
|
error. The geodetic and cartographic base work, GPS-techniques |
|
and user's navigation activities are all measuring after |
|
measuring, and errors are by definition an inseparable part |
|
of all measuring. This applies even, when all activities are |
|
made in formally correct way; in addition to that errors are |
|
caused by misinterpretations, misunderstandings, operational |
|
errors etc. The total error is the sum of the errors made in |
|
different phases of a positioning or navigation act. </font></p> |
|
</blockquote> |
|
|
|
<h1><font size="2" face="Verdana">Acknowledgements</font></h1> |
|
|
|
<blockquote> |
|
<p><font size="2" face="Verdana">I want to thank Ph.D. Matti |
|
Ollikainen for his kind advice and for his corrections of |
|
some mistakes and inaccuracies in this article. </font></p> |
|
<p><font size="2" face="Verdana">I also want to thank all |
|
other individuals, who have kindly commented this article, |
|
for their valuable input.</font></p> |
|
</blockquote> |
|
|
|
<h1><font size="2" face="Verdana">References</font></h1> |
|
|
|
<blockquote> |
|
<ul> |
|
<li><font size="2" face="Verdana">Hirvonen, R.A., 1949: |
|
Die Gauss-Kr¸gersche Projektion f¸r breite |
|
Meridianstreifen auf dem Internationalen Ellipsoide. |
|
In Publication of the Finnish Geodetic Institute no |
|
36 (in German)</font></li> |
|
<li><font size="2" face="Verdana">Ollikainen, M., 1993: |
|
GPS-koordinaattien muuttaminen |
|
Kartastokoordinaateiksi. Geodeettinen laitos, tiedote |
|
8 (Converting GPS coordinates to Finnish National |
|
Coordinate System coordinates, Finnish Geodetic |
|
Institute, research note 8, in Finnish)</font></li> |
|
<li><font size="2" face="Verdana">Poutanen Markku, 1998, |
|
GPS-paikanm‰‰ritys - ISBN 951-9269-89-4, |
|
Publication of </font><a |
|
href="http://www.ursa.fi/english.html"><font size="2" |
|
face="Verdana">Ursa</font></a><font size="2" |
|
face="Verdana"> no 64 (GPS-positioning, in Finnish)</font></li> |
|
<li><font size="2" face="Verdana">Ollikainen, M., H. |
|
Koivula and Markku Poutanen, 2000. The densification |
|
of the EUREF network in Finland. The Publication of |
|
Finnish Geodetic Institute, no. 129. P.O. Box 15, FIN-02431 |
|
Masala</font></li> |
|
<li><font size="2" face="Verdana">Ollikainen, M., Koivula |
|
H., Poutanen M., 2001: EUREF-FIN koordinaatisto ja |
|
EUREF-pistetihennykset Suomessa, Geodeettinen laitos, |
|
tiedote 24 (EUREF-coordinates and EUREF-densification |
|
in Finland, Finnish Geodetic Institute, research note |
|
24, in Finnish)</font></li> |
|
<li><font size="2" face="Verdana">Suomen kartasto, vihko |
|
112 (Finnish mapping, book 112, in Finnish)</font></li> |
|
<li><a href="http://www.jhs-suositukset.fi/suomi/jhs153"><font |
|
size="2" face="Verdana">Public Recommendation 153</font></a><font |
|
size="2" face="Verdana">, JHS 153, Realization of the |
|
pan-European coordinate system ETRS89 in Finland</font></li> |
|
<li><a href="http://www.jhs-suositukset.fi/suomi/jhs154"><font |
|
size="2" face="Verdana">Public Recommendation 154</font></a><font |
|
size="2" face="Verdana">, JHS 154, Map projections |
|
and plane coordinates used with EUREF-FIN as well as |
|
accurate datum transformation methods</font></li> |
|
<li><font size="2" face="Verdana">Marko Ollikainen and |
|
Matti Ollikainen, 2004, </font><a |
|
href="http://www.maanmittauslaitos.fi/sites/default/files/Finnish_Coordinate_Systems.pdf"><font |
|
size="2" face="Verdana">The Finnish Coordinate |
|
Reference Systems</font></a><font size="2" |
|
face="Verdana">. Published by the Finnish Geodetic |
|
Institute and the National Land Survey.</font></li> |
|
</ul> |
|
</blockquote> |
|
|
|
<p><a href="../gb/index.htm"><font size="2" face="Verdana">Eino |
|
Uikkanen's homepage</font></a><font size="2" face="Verdana"> </font></p> |
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