Inverse monopulse technique Inverse monopulse seeker

one way avoid many of these problems use monopulse radar technique. in these systems, radar signal split in 2 before sent antenna. 2 paths include form of encoding remains intact after reflecting off target. polarization common solution. filters split signal 2 components, , comparison of relative strengths can made before. however, if signals directional, in case of polarization, there no need spin antenna - difference between signals can used determine directionality.

the major advantage of technique comparison instantaneous, completed within length of 1 pulse. allows seeker reject signals received @ different times, making highly resistant random jamming pulses, being able reject reflections off ground. also, because signals cause glint take place on period longer 1 pulse, problem largely eliminated; in testing, majority of skyflash missiles hit target aircraft directly, compared original aim-7 s conical scanning solution brought missile within 20 to 30 metres (66–98 ft). additionally, able attack aircraft flying @ 1,000 feet (300 m) altitude, limit selected allow tracking cameras see target. these tests demonstrated there no practical lower altitude limit technique.

the downside inverse monopulse seeker twofold. one, requires radar on launch platform have monopulse encoding, or there no directional signal seeker process. links such missiles aircraft more tightly more generalist conical scanning systems can used radar seeker can tune in. more importantly, seeker more complex , requires more electronics, not possible in era of vacuum tube electronics , became practical in 1970s. instance, skyflash receiver had single fixed antenna, required 4 receivers, 1 each channel , comparitor electronics generate 3 signals, 1 sum of signals, , 2 differences.