For all you folks following along at home who want to see some pretty
pictures, here you go!

https://drive.google.com/open?id=1pnFV5MWkx5YR9ZlutetgDrejNG9SZx6Zp6xbdKl48Ps&authuser=0

I sometimes have blissful moments of forgetting that Google wants all of
my data, always.  In this particular instance, we may as well let them
help out.  So there is a Google Drive folder linked at the bottom of the
doc which contains "gpslog_big-outside.raw" along with various other
files we have been talking about.

Transmitting the prn1 converted to complex floats through the HackRF and
grabbing a sample with jGPSv3 correlates!  Check out that
signal-to-noise ratio for SV 1!.

$ ./soft-correlator < data/gpslog_prn1_rx.raw
# frequency of 1-bits: i-sign 51.7%, i-mag 33.6%, q-sign 48.8%, q-mag 30.0%
# SV, S/N ratio, doppler shift (Hz), code phase (chips), sample clock error 
(chips/s)
* 1     601.457508      -14801.532243   253.000000      9.611385
* 2     14.721936       -799.801893     330.000000      0.519352
* 4     15.425549       -6801.062185    669.000000      4.416274
* 11    14.114000       -10801.489275   302.000000      7.013954
* 17    15.250208       2199.254809     77.000000       -1.428088
* 24    14.148221       -7794.920364    335.000000      5.061637
* 28    13.145979       14199.180477    545.000000      -9.220247
* 30    13.199176       5798.007429     466.750000      -28.764940
# 8 satellites in view; average clock error -1.598834 chips/s

I'm surprised to see that the added noise was enough to correlate the
pseudo-noise sequence from other satellite vehicles.  This was done in
the basement, so I know it wasn't accidentally picking up any real
satellites.

-- 
Kenny
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