Data transmission by radar

The use of the radar for jamming-resistant data transmission was investigated. The possibilities and limits of data transmission via mechanically rotating radars are presented. The low time and spatial duty cycle of the radar pulses and the antenna main beam, respectively, result in a low average data rate. Thus only short messages of the order of 100 bit during each antenna rotation cycle can be transmitted with high resistance against jamming. A lower immunity from disturbance must be tolerated in order to increase the data rate. Several methods are described, consisting of the modification of signal parameters and modulation, and the use of the antenna sidelobes for transmission. A concept of burst transmission with preamble detection in order to circumvent the high detection loss due to fluctuating sidelobes is given.