136
6 Detection of Radio Signals and Its Parameters Measuring
is selected based on tactical requirements and conditions of radar operation, it is
possible to determine univalently a desired threshold value y thr .
We should note that perfect processing system of coherent signals is the most
effective in terms of detection and use of signal energy at radar input. As it was
mentioned before, to coherent signals are referred all signals, in which a phase
structure of HF signal inclination is definitely known. In particular, if a coherent
pulse burst (train) is used, then a signal energy E equals to energies sum of all pulses
in burst E = N p E 1 , where N p —number of pulses and E 1 —energy in one pulse.
The required signal energy in perfect system for a target detection is minimal as
compared with other none-perfect systems.
Detection characteristics are calculated and graphically plotted based on obtained
formulas (6.15–6.19). The detection characteristics for an ideal case of target detection unit operation are performed on Fig. 6.7. The dependence of correct detection
probability P cd (expressed as percentage) as a function of R parameter (relation of
signal energy to spectral noise density R = 2E/N o ) in decibels at specified values
of false alarm probability P f a is performed. R value in decibels, as normal, can be
found according to the following formula:
R [d B] = 10lg R.
(6.20)
Fig. 6.7 Targets detection
characteristics at use of
coherent signals in lossless
6 Detection of Radio Signals and Its Parameters Measuring
is selected based on tactical requirements and conditions of radar operation, it is
possible to determine univalently a desired threshold value y thr .
We should note that perfect processing system of coherent signals is the most
effective in terms of detection and use of signal energy at radar input. As it was
mentioned before, to coherent signals are referred all signals, in which a phase
structure of HF signal inclination is definitely known. In particular, if a coherent
pulse burst (train) is used, then a signal energy E equals to energies sum of all pulses
in burst E = N p E 1 , where N p —number of pulses and E 1 —energy in one pulse.
The required signal energy in perfect system for a target detection is minimal as
compared with other none-perfect systems.
Detection characteristics are calculated and graphically plotted based on obtained
formulas (6.15–6.19). The detection characteristics for an ideal case of target detection unit operation are performed on Fig. 6.7. The dependence of correct detection
probability P cd (expressed as percentage) as a function of R parameter (relation of
signal energy to spectral noise density R = 2E/N o ) in decibels at specified values
of false alarm probability P f a is performed. R value in decibels, as normal, can be
found according to the following formula:
R [d B] = 10lg R.
(6.20)
Fig. 6.7 Targets detection
characteristics at use of
coherent signals in lossless