Chapter 9
Compensation of Signals from Stationary
Objects
The problem of detecting and discriminating (isolation) of moving targets is solved by
signal separation from moving targets and interfering reflections (IRf), and improving
the conditions for detecting of a signal, reflected from a moving target. Signal extraction of moving target is a joint task of target resolution and detection. At present,
various devices are known for the technical implementation of methods for identifying moving targets based on the use of coherent impulse signals. Such devices are
divided into two groups:
(1) devices for suppression (rejection) of interfering reflections;
(2) devices for extraction and accumulation of signals from moving targets.
The signals from IRf represent radio signals in the form of passive interference,
reflected when they are irradiated by sounding signals of the radar. Their effect is
manifested in the suppression and masking of signals, reflected from the observed
target. The intensity of interference can significantly exceed not only the level of the
receiver’s own noise, but also the useful signal of target, which complicates its radar
observation and sometimes makes it completely impossible.
Passive interference (clutters) is created by reflections of radar signals from
objects, which are in the radar surveillance zone. Natural passive interference is
reflection from land and sea surfaces; terrain feature; moisture targets (meteorological
formations) or hydrometeors (rain, snow, fog); atmospheric inhomogeneities (traces
of meteorites in the atmosphere, lightning, “angel clutters,” etc.). Passive jamming
(intentional passive interference) is reflection from clouds of dipole reflectors,
aerosols or ionized particles, as well as reflections from decoys.
The features of passive interference include:
• their appearance only when the radar transmitter is operating;
• location of the interfering source either in one resolution element with a useful
target or in close vicinity from it;
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
D. A. Akmaykin et al., Theoretical Foundations of Radar Location
and Radio Navigation, Springer Aerospace Technology,
https://doi.org/10.1007/978-981-33-6514-8_9
167
Compensation of Signals from Stationary
Objects
The problem of detecting and discriminating (isolation) of moving targets is solved by
signal separation from moving targets and interfering reflections (IRf), and improving
the conditions for detecting of a signal, reflected from a moving target. Signal extraction of moving target is a joint task of target resolution and detection. At present,
various devices are known for the technical implementation of methods for identifying moving targets based on the use of coherent impulse signals. Such devices are
divided into two groups:
(1) devices for suppression (rejection) of interfering reflections;
(2) devices for extraction and accumulation of signals from moving targets.
The signals from IRf represent radio signals in the form of passive interference,
reflected when they are irradiated by sounding signals of the radar. Their effect is
manifested in the suppression and masking of signals, reflected from the observed
target. The intensity of interference can significantly exceed not only the level of the
receiver’s own noise, but also the useful signal of target, which complicates its radar
observation and sometimes makes it completely impossible.
Passive interference (clutters) is created by reflections of radar signals from
objects, which are in the radar surveillance zone. Natural passive interference is
reflection from land and sea surfaces; terrain feature; moisture targets (meteorological
formations) or hydrometeors (rain, snow, fog); atmospheric inhomogeneities (traces
of meteorites in the atmosphere, lightning, “angel clutters,” etc.). Passive jamming
(intentional passive interference) is reflection from clouds of dipole reflectors,
aerosols or ionized particles, as well as reflections from decoys.
The features of passive interference include:
• their appearance only when the radar transmitter is operating;
• location of the interfering source either in one resolution element with a useful
target or in close vicinity from it;
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
D. A. Akmaykin et al., Theoretical Foundations of Radar Location
and Radio Navigation, Springer Aerospace Technology,
https://doi.org/10.1007/978-981-33-6514-8_9
167