Requirements

Mission Requirements

The system shall be able to receive and decode AX.25 (and other available protocols) telemetry packets from amateur satellites.

The front-end of the system shall be protected from received energy exceeding the limits of the SDR hardware.
The input to the SDR hardware will utilize two separate polarizations to reduce losses in signal strength.
The front-end of the system will have lightning protection.
The front-end of the system shall operate in simplex mode.

The software should produce a waterfall display on a GUI that can be adjusted by the user.
There should be an interface displaying the contents to a user containing the decoded information from an AX.25 signal.
The system shall be accessible to a user operating the program with the option to focus on a particular satellite.
The system should have some means of displaying received data in real time.
The system should be able to switch focus on satellites in real time.

The system shall be designed to receive satellite signals from the Very High Frequency (VHF) band (145.8-146 MHz).
The front-end should be able to filter interference from Verizon’s cell tower.
The system will utilize Doppler correction to receive messages.
The system should indicate if the receiver can receive a strong signal from a satellite but cannot decode a message.
The software should be designed so that it can interface with multiple amateur satellites.
The software should automatically save received data and append new information onto the preexisting file.
The software should automatically save received IQ samples.