[AR] Re: GPS again....
- From: "David W. Schultz" <david.schultz@xxxxxxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Tue, 4 Aug 2015 18:30:29 -0500
On 08/03/2015 03:03 PM, Nathan Bergey wrote:
Not sure why or how much but I think
our log is peppered with dozens of millisecond long holes.
It is taking a long time to suck that 3GB file through the straw the
server has provided but I have started to play around with it.
The first thing I did (after poking around to find that JGPS is the tag
for the raw GPS data) is to extract the time stamps on all of
those packets and plot the differences. This quickly showed that there
are occasional gaps in the data. After a bit more massaging of the data,
here are the gaps so far:
47.140756 0.081569
78.390957 0.126617
78.920875 0.231625
109.067105 0.034037
110.640586 0.228710
135.014773 1.755687
141.997925 0.080251
173.631826 0.094469
210.152500 0.088027
242.073334 0.235092
278.043531 0.205582
308.175787 0.039637
309.744244 0.206678
First column is the difference between the first time stamped JGPS
packet and the current packet. Second column is the difference between
the current time stamp and the previous one. All in seconds. The average
difference was 500 micro-seconds which works out to 2MB/sec.
--
David W. Schultz
http://home.earthlink.net/~david.schultz
Returned for Regrooving
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