Radar is absolutely the most unpredictable form
of speed trap, appearing anywhere at any time.
It also features the most potential inaccuracies.
There are thousands of moving radars mounted on
Highway Patrol cars throughout Australia. Models include
Decatur Genesis, Stalker and Kustom Eagle II.
Decatur "Genesis Select"
is an example of state-of-the-art
moving radar. As with all dual antenna
types, the Genesis can record speeds
of vehicles traveling in both directions
coming towards and going away from
the Patrol Car. The units used in
Queensland (Australia) have a single
radar antenna. They record the speeds
of vehicles coming towards the forward
facing antenna and those in front
going in the same direction. The "DGS" operates within
the Australian "Ka" band.
The specific frequency is 35.1 GHz.
moving radars have been operated
by Highway Patrols in Australia
since the late 1970s. Most are the
KR10 SP model. Some Hawk and Eagle
units are in use with various states.
The Eagle II uses the smaller Ka-band
antennas. The frequency is 34.9 GHz.
Stalker DSR is operated the Victorian Highway Patrol. Perhaps the most advanced moving radar in the world, the dual-antenna version of the Stalker records speeds of vehicles coming and going towards the patrol car in the same or opposite lanes. The Stalker frequency is 34.7 GHz right in the centre of the Australian "Ka" band.
of Moving Radar:
Moving radar is prone to different errors than
stationary radar. The most common is "tracking"
error. A portion of the radar beam reflects off
the "terrain" to calculate the speed
of the patrol vehicle. The radar thinks it is
stationary and the road is proceeding towards
it at speed. Sometimes the radar picks up reflections
from large stationary or moving objects thereby
producing a tracking velocity that is lower than
true speed. When subtracted from the "closing"
velocity of the police and target vehicle, the
target speed is increased proportionately. An
innocent driver can be ticketed.