A Meteorological Telemetry System for Gun-Launched Probes

A telemetry system has been developed for meteorological investigations of the upper atmosphere that is capable of withstanding gun-launched environments of 60 000 g. This system was developed for the Project HARP (High Altitude Research Probe) 5-inch gun. The telemeter is part of a parachute payload that is ejected at altitudes up to 70 km and records temperature during descent. The telemeter consists of a VHF transmitter, with a power output of 300 milliwatts, modulated by a standard IRIG subcarrier oscillator. An in-flight calibrator is used to obtain a 2-point resistance calibration at the input of the SCO. The system is powered by nickel cadmium batteries and is capable of transmission for periods from 30 to 60 minutes.