DGPS TDoA

Recently, some people have observed a DPGS signal on 318 kHz. Existing software displays its location as Shepelevskiy (Leningrad Oblast) ; however KiwiSDR TDoA shows a different likely location.

318 kHz DGPS

4800 symb/sec QPSK signal on 10165 kHz

... noted today on European KiwiSDR. This signal is likely from the same origin as the one described in this blog post and this blog post.

However this time the data stream seems to be pure pseudo-random, at least for all methods of analysis I have tried.

Update 10/12: The signal still carries pseudo-random data

Using GNURadio a perfect constellation diagram can be obtained:

QPSK constellation diagram

... except during times when the signal fades:

QPSK symbols vs. time

The used GNURadio flowgraph, adapted from this tutorial, is shown below.

GNURadio flowgraph