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Radar Signal Processor

The signal processor is that part of the system which separates targets from clutter on the basis of Doppler content and amplitude characteristics. In modern radar sets the conversion of radar signals to digital form is typically accomplished after IF amplification and phase sensitive detection. At this stage they are referred to as video signals, and have a typical bandwidth in the range 250 KHz to 5 MHz. The Sampling Theorem therefore indicates sampling rates between about 500 KHz and 10 MHz. Such rates are well within the capabilities of modern analogue-to-digital converters (ADCs).

The signal processor includes the following components:

• the I&Q Phase Detector,
• the Moving Target Indication and
• the Constant False Alarm Rate detection.

The plot extraction and plot processing elements are the final stage in the primary radar sensor chain. The essential process is that of generating and processing plots as distinct from processing waveforms. The main components are:

• the plot extractor or hit processor (translates hits from the signal processor to plots),
• the plot processor (combines primary radar plots and minimises false plots) and
• the plot combiner (combines primary and secondary plots, uses complementary features to minimise false alarms).

The radar data chain can include the following devices:

• a sensor tracker (it combines some plots of a target to a track), and
• the Multiple Sensor tracker (it combines plots or tracks of other radar sensors).

(The distinction between a correlator and a tracker being, that in the case of a correlator the plot positions are not changed by the process.)

Some of these devises can carried out as a software-modul after the digitalizing of the radar data. The Plot Extractor of the Ukrainian company Aerotechnica corporation (see the picture) is a Radar Data Extractors for all types of radars an is designed to upgrade analogue radars.