file formats

dick
dick
Joined: 3 Dec 05
Posts: 2
Credit: 405,197
RAC: 0
Topic 193424

LS.

Is somewhere a description of the content of the files earth_... and sun_...? Which parameters are given and what units are used?
Similar questions for the other files in the directory ..../einstein.uwm.phys.edu

Dick.

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,125
Credit: 126,931,764
RAC: 13,035

file formats

Quote:

LS.

Is somewhere a description of the content of the files earth_... and sun_...? Which parameters are given and what units are used?
Similar questions for the other files in the directory ..../einstein.uwm.phys.edu

Dick.


Hmmm .... good question.

Quick answer: I think the Earth & Sun files are empherides - positional data - as I believe the calculations are referred back to the frame of the solar system's centre of mass.

But in case that's random rubbish from my head today, let me look into that and I'll get back on that .... :-)

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Bernd Machenschalk
Bernd Machenschalk
Moderator
Administrator
Joined: 15 Oct 04
Posts: 3,938
Credit: 200,150,634
RAC: 44,204

Yes, earth and sun are

Yes, earth and sun are ephemeris files, describing the motion of the sun and earth.

They are plain ASCII files. After the 1st header line there are 10 columns, giving the time (GPS seconds IIRC), 3 Cartesian cords for the position (in units of sec), 3 for velocity (sec/sec) and 3 for acceleration (1/sec). “sec� here means “light-sec� – light travel time from the Solar System Barycenter to the Earth or Sun, respectively.

The other files h1_* and l1_* contain pre-processed data from the detectors in a proprietary binary format, basically some frequency bins of the SFTs of several time stretches of detector data. H1 is data from Hanford, L1 from Livingston. The number in the filename is the base frequency of the data in the file, i.e. the frequency (in Hz) the lowest bins in a file correspond to.

BM

BM

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.