5.3 Operating Space of Radar Location and Radio Navigation Systems
111
We assume that a target fly over time of this surveillance zone t t.fly is more than scan
time (scanning period) T srv :
t t.fly ≥ T srv .
(5.68)
Target fly over time t t.fly should be selected as a least of two values, corresponding
to a target fly over of surveillance zone as both in radial and in tangential directions.
Fly over time in tangential direction (e.g., in azimuth):
t t.fly =
ψ a3 D
V t.tng
,
(5.69)
where ψ az —admissible sector of target fly over in azimuth; D—distance to a target.
This distance should be selected by the least from boundary values. Fly over time in
radial direction t t.fly.r is defined by a value:
t t.fly.rd =
D fly
V t.rd
,
(5.70)
where D fly —admissible distance of target fly over in radial direction (e.g.,
resolution element size in range).
Characteristics of radar surveillance at the most degree depend on type directional
pattern of radar antenna.
Radar surveillance method, applied in radar of a certain type, is imposed by
tactical purpose of the system. Radar structural design should correspond to a set of
requirements to radar air surveillance, the most important of which are:
1. Scan should cover the completely assigned space, for which an illumination
and target signals receiving should be provided, positioned in any point of
surveillance zone in range and angular coordinates. As single and multiple
radio beams pass through a target (depending on surveillance method), the last
one should receive an amount of sounding energy sufficient for its detection at
maximum range.
2. During scanning, an assigned measuring accuracy of target coordinates and
assigned resolution capability on its coordinates should be provided, that is also
determined by efficient radar energy management during beam pass through a
target.
3. Duration of each scanning cycle (period) should be quite short (repetition scan
(sweep) rate—long enough), in order to have a possibility of identification of the
same target, observed in different scan cycles. At fulfillment of the mentioned
condition, a continuous observing (tracking) of a target will be provided, despite
to high approaching (offset) speed of a target and radar.
4. Predetermined operation reliability, specified mass and dimensions of antenna
unit, engaging in realization of radar surveillance should be provided.
111
We assume that a target fly over time of this surveillance zone t t.fly is more than scan
time (scanning period) T srv :
t t.fly ≥ T srv .
(5.68)
Target fly over time t t.fly should be selected as a least of two values, corresponding
to a target fly over of surveillance zone as both in radial and in tangential directions.
Fly over time in tangential direction (e.g., in azimuth):
t t.fly =
ψ a3 D
V t.tng
,
(5.69)
where ψ az —admissible sector of target fly over in azimuth; D—distance to a target.
This distance should be selected by the least from boundary values. Fly over time in
radial direction t t.fly.r is defined by a value:
t t.fly.rd =
D fly
V t.rd
,
(5.70)
where D fly —admissible distance of target fly over in radial direction (e.g.,
resolution element size in range).
Characteristics of radar surveillance at the most degree depend on type directional
pattern of radar antenna.
Radar surveillance method, applied in radar of a certain type, is imposed by
tactical purpose of the system. Radar structural design should correspond to a set of
requirements to radar air surveillance, the most important of which are:
1. Scan should cover the completely assigned space, for which an illumination
and target signals receiving should be provided, positioned in any point of
surveillance zone in range and angular coordinates. As single and multiple
radio beams pass through a target (depending on surveillance method), the last
one should receive an amount of sounding energy sufficient for its detection at
maximum range.
2. During scanning, an assigned measuring accuracy of target coordinates and
assigned resolution capability on its coordinates should be provided, that is also
determined by efficient radar energy management during beam pass through a
target.
3. Duration of each scanning cycle (period) should be quite short (repetition scan
(sweep) rate—long enough), in order to have a possibility of identification of the
same target, observed in different scan cycles. At fulfillment of the mentioned
condition, a continuous observing (tracking) of a target will be provided, despite
to high approaching (offset) speed of a target and radar.
4. Predetermined operation reliability, specified mass and dimensions of antenna
unit, engaging in realization of radar surveillance should be provided.