122
5 Performance Characteristics of Radar Location …
Then, a possibility of non-response equals 1 − K res . Non-response probability by
this interrogator is calculated in accordance with the following expression:
1 − K res =
t
T arv
=
(N − 1)K res t int
T arv
,
(5.91)
where t = (N − 1)K res t int —average time, during which a responder replies to other
(N − 1) interrogators.
Introduce a parameter ν =
t int
T arv
, characterizing a relative value of safety time.
Then, according to (5.91), we can write down:
K res =
1
1 + (N − 1)ν
.
(5.92)
For practice, an inverse problem also is of interest, when by specified probability
of response receiving K res int and at known value ν, it is required to define a maximum
number of interrogators N max , which this responder can operate. With regard to (5.92),
we have:
N max =
[1 − K res int (1 − ν)]
K res int
.
(5.93)
For modern radar location and radio navigation systems, N max ≤ 100.
One of the possible techniques of bandwidth capacity increase of radar location
and radio navigation systems with interrogator is reducing of interrogated pulses
repetition frequency in tracking mode. However, in this case, there are more severe
requirements to distance measuring unit since it should operate normally at less
number of response pulses in a time unit.
5.6 Interference Immunity of Radar Location and Radio
Navigation Systems
From the technical point of view, noise influence on radar and RNS can be in a form
of the following effect:
– desired (valid) signal waveform distortion and change of its main parameters;
– desired signal suppression (signal-to-noise ratio reducing) at signals and noises
traveling through nonlinear elements;
– overloading of receiver, its separate elements (amplifiers, transducers etc.), signals
and data processors, and indicator.
From the tactical point of view, interference effect on radar and RNS can lead to
screening of desired signal (target) by noises, or to imitation of desired signals by
forming of false signals (decoy targets).
5 Performance Characteristics of Radar Location …
Then, a possibility of non-response equals 1 − K res . Non-response probability by
this interrogator is calculated in accordance with the following expression:
1 − K res =
t
T arv
=
(N − 1)K res t int
T arv
,
(5.91)
where t = (N − 1)K res t int —average time, during which a responder replies to other
(N − 1) interrogators.
Introduce a parameter ν =
t int
T arv
, characterizing a relative value of safety time.
Then, according to (5.91), we can write down:
K res =
1
1 + (N − 1)ν
.
(5.92)
For practice, an inverse problem also is of interest, when by specified probability
of response receiving K res int and at known value ν, it is required to define a maximum
number of interrogators N max , which this responder can operate. With regard to (5.92),
we have:
N max =
[1 − K res int (1 − ν)]
K res int
.
(5.93)
For modern radar location and radio navigation systems, N max ≤ 100.
One of the possible techniques of bandwidth capacity increase of radar location
and radio navigation systems with interrogator is reducing of interrogated pulses
repetition frequency in tracking mode. However, in this case, there are more severe
requirements to distance measuring unit since it should operate normally at less
number of response pulses in a time unit.
5.6 Interference Immunity of Radar Location and Radio
Navigation Systems
From the technical point of view, noise influence on radar and RNS can be in a form
of the following effect:
– desired (valid) signal waveform distortion and change of its main parameters;
– desired signal suppression (signal-to-noise ratio reducing) at signals and noises
traveling through nonlinear elements;
– overloading of receiver, its separate elements (amplifiers, transducers etc.), signals
and data processors, and indicator.
From the tactical point of view, interference effect on radar and RNS can lead to
screening of desired signal (target) by noises, or to imitation of desired signals by
forming of false signals (decoy targets).