User's Manual

LX-80 User Manual
Page 13 of 32
synchronization is very complex to achieve so the interference probability between several
radars on the same location is very small.
It is possible that some wideband radiation sources can introduce small and impulse
interference for the short period of time, but this should not, or it is very unlikely to affect
measurements reported by radar sensor.
4.4. Fogging and evaporation
Generally, radar sensors are not affected by fog or evaporation of water unless very
heavy evaporation is present and water density in the air is very high.
The best solution for the distance measurement is in most cases to increase
average period to get better average distance value. As evaporation is naturally very
turbulent event with significant difference in density over the surface area and in time,
averaging of the distance measurement spectrum is solving the problem of accuracy in
such conditions.
4.5. Reflections
Water is very reflective medium for the radar waves and most of the power
transmitted from radar transmitter will be reflected from the water surface. Reflections
of the radar transmitted power beam follow the same physical laws as in optics and every
time radar beam hits the surface part of the power is reflected away from the radar, part
of the power is reflected towards the radar and only a small part of power is absorbed by
the water. Depending on the surface roughness and incident angle ratio between power
reflected in the direction away from the radar and direction back towards the radar can
significantly vary. As incident angle for radars in fixed, only the roughness is determining
the ration in our case.
In the case of level meter where incident angle of transmitted radar beam to the
water is around 90° most of the power is reflected to the sensor and only small portion
of the transmitter power will be dispersed in all directions. Ratio between power reflected
to the sensor and power dispersed in all directions is dependent on the surface roughness
but in general it is very small amount of the energy that is dispersed, and it is very unlikely
that dispersed energy will cause additional multipath problems due to the more reflections
from surrounding objects.