Combined air surveillance and precision approach radar system

Claim 1

A GROUND CONTROLLED APPROACH RADER SYSTEM OPERATIVE SIMULTANEOUSLY AS AN AIRPORT SURVEILLANCE RADAR AND AS A PRECISION APPROACH RADER, COMPRISING: (A) A BEAM FORMING ANTENNA CONTINUOUSLY ROTATED IN AZIMUTH TO SCAN, PERIODICALLY, A SECTOR INCLUDING AN APPROACH PATH FOR AIRCRAFT TO AN AIRSTRIP; (B) MEANS, SUPPORTED ON THE ROTATING PORTION OF THE BEAM FORMING ANTENNA, FOR FEEDING SUCH ANTENNA WITH PULSES OF S-BAND ENERGY AT A FIRST REPETITION FREQUENCY AND FOR CONVERTING ECHO SIGNALS RESULTING THEREFROM TO A FIRST INTERMEDIATE FREQUENCY; (C) MEANS, SUPPORTED ON THE ROTATING PORTION OF THE BEAM FORMING ANTENNA, FOR FEEDING SUCH ANTENNA WITH PULSES OF X-BAND ENERGY AT A SECOND REPETITION FREQUENCY INTEGRALLY RELATED TO THE FIRST REPETITION FREQUENCY WHEN SUCH ANTENNA SCANS THE SECTOR INCLUDING THE APPROACH PATH, AND FOR CONVERTING ECHO SIGNALS RESULTING THEREFROM TO A SECOND INTERMEDIATE FREQUENCY; (D) MEANS, INCLUDING A PAIR OF COMPLEMENTARY FILTER BANKS AND A FIRST AND A SECOND AMPLIFIER, FOR CONVERTING THE ECHO SIGNALS AT THE FIRST AND SECOND INTERMEDIATE FREQUENCY TO VIDEO SIGNALS;