[AR] Re: GPS again....
- From: Nathan Bergey <nathan.bergey@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Wed, 30 Dec 2015 11:27:09 -0800
On Thu, Dec 24, 2015 at 7:24 AM, Paul Breed <paul@xxxxxxxxxx> wrote:
Nathan,
Can you charactorize the data loss in your GPS data?
On average we have runs of about 20 seconds of good data with ~1 to 50
millisecond gaps. No regular pattern is obvious.
We've been working to actually get this together into something easily
shareable. All of our telemetry data is packed in a custom format, so
there are layers of unpacking. We've been careful to make sure what we think
is in the file is really there, since we had this loss issue.
At our meeting last night we were able to get pretty far!
Get the data:
Clone our Launch-12 repo on github (~200 MB):
$ git clone
https://github.com/psas/Launch-12.git
In the 'data' directory there is data stuff, and in 'GPS' I've
included about a minute of raw MAX data already unpacked and labeled,
broken out into two files that are contiguous. File format is detailed
in the readme.
Or just go straight to the directory on github:
https://github.com/psas/Launch-12/tree/gh-pages/data/GPS
If you want *all* the data, as of last night this worked on our
machines, but I've had some reports that something in our unpacking
code breaks for some people:
Get the full telemetry file from annex.psas.pdx.edu (> 3 GB!)
$ wget
http://annex.psas.pdx.edu/Launch-12/flightcomputer.log
Install the latest packed python deserializer:
$ git clone
https://github.com/psas/psas_packet.git
$ cd psas_packet
$ sudo python setup.py install
You should now have the `split-gaps` utility in your path, try
$ split-gaps < flightcomputer.log
You should then have a raw MAX file for each contiguous section of
data, the number after the @ in the filename is when that chunk starts
in seconds from launch, to give you a sense of what piece is what. All
the negative numbers will be sitting still on the pad, for instance.
Further unpacking of the IMU data should work too, simply running
$ log2csv flightcomputer.log
should give you a CSV of every data instrument in the log file, except
the raw GPS of course.
ADIS.csv will have IMU data, the header of the file has a description
of each column.
Let me know if it works!
-Nathan
PSAS
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