Radar Theory (1) PRIMARY RADAR

Question 1

Primary radar principle

Answer 1

Echo(gives range) and search light (gives bearing)

Question 2

Primary radar energy transmitted in the form of ___

Answer 2

Pulses

Question 3

Pulse width and its unit

Answer 3

TIME elapsed in transmission of one pulse

Microseconds

Question 4

PRI ie Pulse recurrence interval/period/time and its unit

Answer 4

TIME elapsed from STARTING of one pulse to STARTING of another pulse

Microseconds

Question 5

PRR or PRF
Pulse recurrence rate or pulse recurrence freq

Answer 5

Number of pulses per sec

Question 6

Relation b/w PRR and PRI

Answer 6

INVERSE
PRF =1/PRI

Question 7

Range covered by primary radar is given by formula

Answer 7

Range = C/2PRF
Range in meters
PRF in pps

Question 8

1nm =

Answer 8

1.852km
6080feet

Question 9

MAX RANGE(primary radar) depends upon

Answer 9

PRF

Question 10

MIN RANGE(primary radar) depends upon

Answer 10

PW ie
Pulse width

Question 11

Angular resolution depends upon

Answer 11

BW
Band width

Question 12

Factors affecting range of primary radar

Answer 12

1) power of transmission
2) ht of transmitter and ht of receiver

Question 13

Relation b/w range and power of trx

Answer 13

Range directly prop to underroot(small4) power
Refer notes if confused

Question 14

To DOUBLE range, power has to be increased by

Answer 14

16 times

Question 15

To TRIPPLE range, power has to be inc by

Answer 15

81 times

Question 16

Relation of range w Tx and Rx

Answer 16

Range (nm)= 1.23underoot ht of tx (feet)+1.23underrootht of rx (feet)

Refer notes if confused

Question 17

Range of radar aka what?

Answer 17

Line of sight

Question 18

Advantage of continuous wave radar over primary radar ?

Answer 18

No minimum range reception restriction