tobin

% Configuration:
%
%  [laser1] --->  [mod1] ---->  [    ]  <--- [mod2] <--- [laser2]
%                               [ BS ] 
%   [PD1] <-------------------  [    ]  ---------------> [PD2]
%
% PD1 and PD2 form a balanced homodyne detector for laser1 and laser2.  If
% you want to consider a "DC readout" type configuration (or a squeezer
% coherent control configuration) where you just have one PD, you can just
% ignore PD2.

tobin

For LIGO Magazine, it's envisioned that we'll have some kind of regular "How does it work?" feature, which will explain various concepts in gravitational wave detection making liberal use of nice illustrations. This is a list of some concepts we might consider illustrating in this way.

Astrophysical stuff

• gravitational waves
• Michelson interferometer as GW detector
• multiple GW detectors as interferometric detector network
• resonant bar detector
• Robert Forward's interferometer
• pulsar timing for GW detection
• Hulse-Taylor pulsar system

tobin

foo

tobin

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

char charset[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789~!@#$%^&*-+=";

int main(int argc, char **argv) {
  srand(time(NULL));
  for (int i=0; i<10; i++) 
    printf("%c", charset[rand() % sizeof(charset)]);

tobin

% This code answers the question at http://dsp.stackexchange.com/a/110/64

N = 150;    % Order of LPC auto-regressive model
P = 500;    % Number of samples in the extrapolated time series
M = 150;    % Point at which to start predicting

t = 1:P;

x = 5*sin(t/3.7+.3)+3*sin(t/1.3+.1)+2*sin(t/34.7+.7); %This is the measured signal

tobin

function phi = findSystematicPhase(X)
% This function finds the angle (in radians) that minimizes the sum of the
% squared imaginary components of a list (or matrix) of numbers.  Note that
% there is an ambiguity of pi radians in the result; resolving that is up
% to you.
%
% Tobin Fricke - 2009-01-05

% Possible future enhancement: consider the matrix of errors on the
% real and imaginary components of X, and weight the corresponding

tobin

pt@pt-ws2 /opt/src/projects-aei/tds/TDS $ ls
Makefile     tdscntr.cc     tdsdcpl     tdsline     tdsread.o     tdssine.cc
Makefile.am  tdscntr.o      tdsdcpl.cc  tdsline.cc  tdsrelief     tdssine.o
Makefile.in  tdsdata        tdsdcpl.o   tdsline.o   tdsrelief.cc  tdswait.cc
tdsalgn.cc   tdsdata.cc     tdsdmd      tdslink     tdsrelief.o   tdswfs.cc
tdsavg       tdsdataGPS     tdsdmd.cc   tdslink.cc  tdsresp       tdswrite
tdsavg.cc    tdsdataGPS.cc  tdsdmd.o    tdslink.o   tdsresp.cc    tdswrite.cc
tdsavg.o     tdsdataGPS.o   tdsdump.cc  tdsread     tdsresp.o     tdswrite.o
tdscntr      tdsdata.o      tdshead.hh  tdsread.cc  tdssine
pt@pt-ws2 /opt/src/projects-aei/tds/TDS $ ./tdsavg

tobin

I want to make a short cable to connect the electronics box directly to an accelerometer. In the isolation_table_wiring.sch document, I find:

--- ACC ---
1. EXC +
2. ACT +
3. SENS +
4. N/C
5. N/C
6. EXC -

7. ACT -

tobin

Dr. Klaus-Wolfgang Höhne
http://flug-med.net/
Alleestraße 2 
30167 Hannover

Dr. Angelika Stenzig
http://www.drstenzig.de/flugmedizin/
Lister Platz 1 
30163 Hannover

tobin

EPICS and MEDM on Ubuntu 9.10

I re-installed recently on a new Ubuntu 9.10 system. It was actually totally painless and just took 15 minutes.

The first step is to make a directory for the EPICS software to live in. It's conventional to put it in "/opt/epics". So make this directory:

cd /opt

sudo mkdir epics