1) You are designing an air search radar system for a (insert
country of your choice) Navy Frigate with a 25 meter mast.
-At what range will an aircraft flying at an
altitude
of 300 meters enter radio (radar) line-of-sight?
-Suppose the aircraft dips to an altitude of 10
meters. What range will it enter radio line-of-sight?
2) Design specifications call for a .5 µ second pulse
and
detection out to 100.8 kilometers.
-Calculate the maximum allowable Pulse Repetition
Frequency.
3) Systems Engineers have decreed that the maximum allowable false alarm rate is 3.5 false alarms per minute. Calculate the necessary P(False Alarm) to achieve this given that P(F.A.) is a function of the P.R.F. calculated in (2).
4) Calculate the received peak power necessary to detect a target with probability = .95 given a system temperature of 2000K.
5) Calculate the transmitter peak power necessary to yield the received power of (4) for a target at maximum range, with a radar cross section of 100 square meters, carrier frequency = 15 GHz, and antenna gain of 30 dB.
6) Given an antenna with beam width equal to .3 degrees, calculate the maximum allowable antenna rotation rate using the PRF of (3).
7) While on patrol, an aircraft which is being tracked by
this
system launches a 1000 Km/hr Exocet Missile ( with a radar cross
section
of .1 square meters) while 35 Km away. This missile immediately drops
down
to an altitude of 4 meters.
-At what range will this missile enter radio
line-of-sight?
-How many seconds will you have to detect the target
(based on the range just calculated)?
-Calculate P(detection) at the range just
calculated.
This problem set 'inspired' by the Iraqi Exocet missile attack on
the
USS Stark in the Persian Gulf, 17 May 1987.
To probe further, read Missile Inbound by Jeffrey
Levinson
and Randy Edwards, Naval Institute Press, 1997.