| MORE from page 11 on.
Doppler radar units have an audio tone "doppler audio" which translates reflections from the beam into tones.
While driving and spraying K band (for example) the tones increase WRT oncoming traffic and each tone pitch respresents a high pitch which = a higher speed. Oscillating tones are two or more reflections being read at the same time. (hence different speed displays depending on the sample rate of the radar unit.
BACK TO LIDAR / LAser.
This Audio tone is generated. Its synthesised. FAKE.
Its derived from the info (pulses) read by the unit so depending on the filtering and processing of pulses to "make" a reading the audio tones generated will just be an audio equivilant of the "processed info".
In other words, if the manipulated data isn't an accurate reflection (distance) of the moving object (over time) then its generated tone is not a true representation of objects actual velocity. IMHO.
Page 11
Laser "is only a tool to be used by the operator. It is NOT a primary function, but secondary to the operator's visual estimation of speed. TRACKING HISTORY of the target is essential, even with a laser based device."
1. Visually observe target vehicle and estimate its speed.
2. Obtain a locking tone.
3. Obtain a reading with the laser and compare the speed reading with the visual estimate. THIS SHOULD BE DONE over a PERIOD OF TIME 2-4 seconds."
While the lidar and lasers "compute" the speed in 1/3 of a second or faster, 2-4 seconds of montioring is NEEDED to verify a valid reading
My FAVORITE:
"As we will see later, there are several anomalies that MAY affect the operation of laser. (REALLY????) therefore, careful tracking history, as with radar, will eliminate or redue misinterpreted readings." Page 11
More later  |