Development of a Low-Resource AM Radio Receiver for Sounding Rocket Applications*

Ground-based transmissions combined with rocket-based receivers have long been used to produce absolute measurements of electron density in the D-region. While these techniques date back to the Friedrich and Seddon methods of the 1950s, recent advances in microcontrollers and software-defined radios provide a powerful alternative to analog systems. Recently, analog AM radio components have become scarce and lack interfacing ability, while modern SDRs offer a better alternative to studying the ionosphere. Bulky traditional software defined radios (i.e., Ettus, HackRF, RX888, etc) require a power hungry host computer (Raspberry Pi). We present a low cost alternative method using the Teensy Convolutional SDR which is composed of an analog downconversion board and a sampling audio card. We further present results of laboratory testing of the Teensy Convolutional SDR's basic signal reception and signal strength properties, power draw, and mechanical layout. This work is in pursuit of an upcoming Rocksat-X student sounding rocket mission, where we will test the SDR in the space environment using existing AM radio transmitters as the emitters of opportunity.