Command signal transmission for satellites - correlates received radio signal with signals stored before flight

摘要

A method of command transmission to satellites or flying objects is based on a pre-flight storage of analogue command codes in the satellite receiver by means of an umbilical connection. Multidigit binary signals are generated by a random generator and individually arranged into command codes. In the transmitter an FM carrier signal is modulated with the code signals which serve as reference signals following their storage in the memories in the satellite receiver. Signals received in flight are compared with the stored signals by a correlation process. If a predetermined corelation is attained, the received signal is recognised as a command code. The binary signals may be in the form of double-frequency modulation of the carrier frequency.