图吧坐标转WGS84坐标

wgs84.rb

  def transform_coordinate
    begin
      wgLon,wgLat = mapBar2WGS84(self.lon,self.lat)
      gdlat,gdlon = transform(wgLat, wgLon)
      self.lat,self.lon = gdlat.round(6),gdlon.round(6)
      self.coordinate_updated = 1
      self.save
    rescue => e
      Rails.logger.error e
      Rails.logger.error "id:#{self._id},coordinate:#{self.coordinate}"
    end
  end

  def mapBar2WGS84(lon, lat)
    # 图吧坐标转WGS84坐标
    # 参数：
    # lon - 经度
    # lat - 纬度
    # 返回值：
    # 经度, 纬度
    lon = lon * 100000 % 36000000.0
    lat = lat * 100000 % 36000000.0
    lon1 = -(((Math.cos(lat / 100000)) * (lon / 18000)) + ((Math.sin(lon / 100000)) * (lat / 9000))) + lon
    lat1 = -(((Math.sin(lat / 100000)) * (lon / 18000)) + ((Math.cos(lon / 100000)) * (lat / 9000))) + lat
    lon2 = -(((Math.cos(lat1 / 100000)) * (lon1 / 18000)) + ((Math.sin(lon1 / 100000)) * (lat1 / 9000))) + lon + ((lon > 0) ? 1 : -1)
    lat2 = -(((Math.sin(lat1 / 100000)) * (lon1 / 18000)) + ((Math.cos(lon1 / 100000)) * (lat1 / 9000))) + lat + ((lat > 0) ? 1 : -1)
    return lon2 / 100000.0, lat2 / 100000.0
  end

  # World Geodetic System ==> Mars Geodetic System
  def transform(wgLat, wgLon)
    ###
    # transform(latitude,longitude) , WGS84
    # return (latitude,longitude) , GCJ02
    ###
    a = 6378245.0
    ee = 0.00669342162296594323

    if outOfChina(wgLat, wgLon)
      mgLat = wgLat
      mgLon = wgLon
      return
    end
    dLat = transformLat(wgLon - 105.0, wgLat - 35.0)
    dLon = transformLon(wgLon - 105.0, wgLat - 35.0)
    radLat = wgLat / 180.0 * Math::PI
    magic = Math.sin(radLat)
    magic = 1 - ee * magic * magic
    sqrtMagic = Math.sqrt(magic)
    dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * Math::PI)
    dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * Math::PI)
    mgLat = wgLat + dLat
    mgLon = wgLon + dLon
    return mgLat,mgLon
  end

  def outOfChina(lat, lon)
    if (lon < 72.004 or lon > 137.8347)
      return true
    end
    if (lat < 0.8293 or lat > 55.8271)
      return true
    end
    return false
  end

  def transformLat(x, y)
    ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(x.abs)
    ret += (20.0 * Math.sin(6.0 * x * Math::PI) + 20.0 * Math.sin(2.0 * x * Math::PI)) * 2.0 / 3.0
    ret += (20.0 * Math.sin(y * Math::PI) + 40.0 * Math.sin(y / 3.0 * Math::PI)) * 2.0 / 3.0
    ret += (160.0 * Math.sin(y / 12.0 * Math::PI) + 320 * Math.sin(y * Math::PI / 30.0)) * 2.0 / 3.0
    return ret
  end

  def transformLon(x, y)
    ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(x.abs)
    ret += (20.0 * Math.sin(6.0 * x * Math::PI) + 20.0 * Math.sin(2.0 * x * Math::PI)) * 2.0 / 3.0
    ret += (20.0 * Math.sin(x * Math::PI) + 40.0 * Math.sin(x / 3.0 * Math::PI)) * 2.0 / 3.0
    ret += (150.0 * Math.sin(x / 12.0 * Math::PI) + 300.0 * Math.sin(x / 30.0 * Math::PI)) * 2.0 / 3.0
    return ret
  end