commit b6ca979f9bab10b2e5dd285f29b33c5c5eb215b5
Author: Erwin Ried <1091420+eried@users.noreply.github.com>
Date:   Tue Apr 21 13:40:17 2020 +0200

    Transmitters / GPS Sim

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+This app allows you to broadcast GPS baseband signal data streams. You can use [gps-sdr-sim](https://github.com/osqzss/gps-sdr-sim) to generate data for this app.  
+
+## Example
+`gps-sdr-sim -e brdc3540.14n -l 30.286502,120.032669,100 -b 8`
+
+That will create a `gpssim.bin` file that you rename to `BBD_NNNN.C8` and then create `BBD_NNNN.TXT` with:
+```
+sample_rate=2600000
+center_frequency=1575420000
+```
+
+Copy to your PortaPack MicroSD and open the file from the GPS Sim app.
+
+## References
+https://blog.csdn.net/shukebeta008/article/details/103270214
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