User's Manual

GLX-RSS-4 User Manual

Page 11 of 16

Picture 5. Radar coverage area - vertical plane

Minimal detectable target

RSS-4 radar sensor detects moving and stationary targets in the radar field of

view by transmitting modulated electromagnetic wave in 24 GHz frequency range (K-

band), and measuring the frequency shift of the reflected electromagnetic wave.

Reflection of the electromagnetic wave from the target is making it detectable and

stronger the reflection is, better are the chances to detect target and target will be

detectable in the greater distance from the radar sensor. Radar cross-section (RCS) is a

measure of how detectable an object is with a radar. Several different factors determine

how much electromagnetic energy returns to the source such as:

• material of which the target is made

• absolute size of the target

• relative size of the target (in relation to the wavelength of the illuminating radar)

• the incident angle (angle at which the radar beam hits a portion of target which

depends upon shape of target and its orientation to the radar source)

• reflected angle (angle at which the reflected beam leaves the part of the target

hit, it depends upon incident angle)

• the polarization of transmitted and the received radiation in respect to the

orientation of the target

In respect to above factors that are defining target radar cross-section and target

detect ability by the radars, some typical values of the measurement radar cross-section

for typical targets are:

• Insect: 0,00001 m

(-50dBsm)

• Small bird: 0,008 m

(-20,97dBsm)

• Large bird: 0,01 m

(-20dBsm)

• Crawling human: 0,25 m

(-6 dBsm)