gr-satnogs/examples/README.md

Examples

This directory contains a set of useful examples and flowgraphs for testing and demonstrating the performance of the different components of this OOT module

Files

• morse_ref.wav : This is a reference file containing the HELLO WORLD message. The file is sampled at 8 KHz and the audio frequency is 700 Hz. The Morse code Words per Minute (WPM) is about 20.

Flowgraphs

• test_matched_filter.grc: Demonstrates the performance of the implemented matched filter for CW decoding.

• morse_decoding_flowgraph.grc: This flowgraph decodes a CW signal and prints the corresponding message at the stdout. To demonstrate the capabilities of the decoder, signal and noise power GUI sliders are provided for easy testing and experimenting.

• ax25_example.grc: This flowgraph semonstrates the AX.25 encoder and decoder. It has two different AX.25 payload source blocks. The first one is the Debug Message Source block that assigns as payload a predefined message, whereas the second one is a UDP Message Source block that receives the AX.25 payload from a UDP packet.

• test_rigctl.grc: This particular flowgraph demonstrates the capabilities of the module implementing a portion of the rigctld functionality. It received rigctl commands through a TCP socket and produces the appropriate messages. In the example these messages are received from the Doppler correction block. To generate rigctl commands you can use the GPredict software. Note that you have to specify the frequency of the transmitter satellite. As this block does not use any satellite signal rather than a simple sine, you do not expect any correction at all. However you will be able to see how smoothly the sine peak is drifting. This drift in normal situations will be the correction offset.