摘要: Radio frequency telemetry of surface to air missiles during the environmental, guidance and control, and homing phases was studied. The use of error detection codes in PCM - FM telemetry system is discussed. However, the low trans... 展开 Radio frequency telemetry of surface to air missiles during the environmental, guidance and control, and homing phases was studied. The use of error detection codes in PCM - FM telemetry system is discussed. However, the low transmission bit rate, the expected bit error rate (BER) and the short flight duration imply that error detection codes are not necessary. The transmission problems caused by ionization of the air by the motor efflux were assessed. As these happen at the start of a flight when the range effects are low, ionization is not usually a significant problem. A single multiplexor hybrid PCM - FM / FM - FM is recommended. It is shown that as long as the range of the missile is 40 km then a 3 W transmitter is adequate to transmit the data with an acceptable BER. 收起