SS-FM: A Telemetry Technique for Wide-Band Data

A telemetry technique is discussed which promises to alleviate an enigma facing the telemetry engineer: How to adequately transmit the avalanche of vibration and other wide-band data desired in the development phase of large missiles and launch vehicles. The data channels are stacked in the frequency spectrum as single-sideband subcarriers which frequency-modulate the RF carrier. The system design utilizes to advantage the statistical properties of vibration data to achieve maximum data transmission efficiency from the available RF carrier deviation. However, in contrast to proposed statistical predigestion techniques, the data is transmitted in raw form. The background and philosophy of the technique is given, followed by a general description of the SS-FM vehicle and ground telemetry equipment utilized in the Saturn vehicle program and a summary of system characteristics and performance.