| RADAR SYSTEMS AND NAVIGATION (B.Tech 6TH & 7TH Semester, 2052) Time : 3 Hours Maximum Marks : 60 NOTE:- This paper consist of Three Sections. Section A is compulsory. Do any Four questions from Section B and any two questions from Section C Section-A Marks : 20 1 (a) Define multiple time around echo in radar systems. (b) Give the block diagram of a pulsed radar system. (c) The noise entering the IF amplifier is white Gaussian. If threshold-to-Noise ratio is 14 dB, what will be the probability of false alarm ? (d) Calculate the maximum unambiguous range of a low PRF pulse radar with a PRF of 100 Hz. (e) An aircraft is flying at a speed of 250 km/h. Compute the Doppler frequency for a radar operating at a frequency for a radar operationg at a wavelength of 5 cm. (f) For a radar operating at 10 Ghz and PRF of 300 Hz, calculate the first, blind speed. (g) How is tracking in range achieved ? (h) Enlist different techniques for Electronic counter measures. (i) Mention the operating frequencies, power requirements and expected range of an actual radar system. (j) Explain the use of loop antenna for radio direction finding. Section-B Marks:5 Each 2.A 12 Ghz radar has the following characteristics : peak transmitted power = 240 kW, power gain of antenna = 2400, minimum detectable signal power by reciever = 10 raised to -14 wats, cross-sectional area of radar antenna = 10 m qube. Find out maximum range upto which a target of 3 m square can be detected 3. Compare different types of tracking methods. 4. Give the case study of an actual raar system. 5. Write a technical note on Electronic counter-counter measures adopted in antijamming. 6. With the help of block diagram, describe an automatic finder for aircrafts Section-C Marks : 10 Each 7. Derive an expression for blind spped of an MTI radar. Discuss the effect of large wavelength and large pulse repetition frequency on lowest blind speed of target. What is staggered pulse repetition frequency and what are its advantages ? 8.For a radar system, the following paprmees are given : Bandwidth of If amplifier = 1 MHz. Tolerable average false alarm time = 15 min. probability of false alarm = 1.11 x 10 -9(power) Find the ratio of threshold voltage to r.m.s. value of noise voltage necessary to achieve this false alarm time. Derive the formula used. 9. Explain the working of an FM-CW radar used to measure the height fo an aircraft during vertical take off. in a FM-CW radar system, the averafe meter reading is 41 khz and difference meter reading is movinf . Also find the range at which the target is expected. The carrier frequency is 4.2 GHz. |
| RADAR SYSTEMS AND NAVIGATION |
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