Stalker Doppler audio question: ascending/descending sound

Z0RR0

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Hi guys,

I’m looking for some quite specific info about the Stalker II MDR and Stalker Dual DSR Doppler audio sound/pitch/tone (don’t know what term is better). I suppose, it’s the same on any modern Stalker. I looked at the manuals and found nothing.

Is this correct?
- ascending sound = measured car moving toward the radar gun
- descending sound = measured car moving away from the radar gun


Or are there any differences depending on the mode (moving/stationary)?

Also: can someone give a source for this info?

Background:
I’ve been looking at a lot of court documents lately and it’s a complete mess. Let’s take a typical situation: cop is driving with Stalker always on and measuring oncoming traffic.
- In 75% of the cases it is said, the sound was ascending
- In 20% of the cases it is said, the sound was descending
- In 5% of the cases it is said, the sound was constant/not changing
Obviously, in all those cases the ascending/descending/constant sound was seen as evidence that it was indeed the oncoming car that the officer measured. I just can’t believe it can be the absolute opposite in the same situation (and with the same gun).

Also, there are some rulings, that say that an ascending sound means the measured car is accelerating and descending means the car is deaccelerating/breaking but this is very rare (<1% maybe).


Thanks a lot for any input!
Z.


PS: sorry, if this is the wrong subforum
 

V1Jake

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When I run my Stalker DSR in stationary the tone does increase as the cars ahead speed up. It's very dull low tone and eventually goes to a higher pitched sound based on their speed. It's the same while in moving mode. If doing same direction the cars at your speed will have a lower tone and the ones moving away faster will have a higher tone. For opposite direction the tones will be higher off the bat but the much faster cars will have a very very higher pitched tone
 

sdrawkcaB

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Whenever @SquirrelMaster passes a cop on the highway, it results in the LEO filing for hazard pay due to tinnitus.
:pervert:
 

thebravo

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for some technical reading with math:
Code:
https://copradar.com/chapts/chapt3/ch3d1.html &  https://copradar.com/chapts/chapt3/ch3d1a.html
 

Z0RR0

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for some technical reading with math:
Code:
https://copradar.com/chapts/chapt3/ch3d1.html &  https://copradar.com/chapts/chapt3/ch3d1a.html
Thanks!

The analogy with sound makes sense: a police car driving with the siren on,
speed 55 mph and the siren at 1000 Hz (so one sound wave every 1/1000 sek).

Driving towards me: I get 1078 Hz instead of 1000 Hz - ascending pitch
Driving away from me: I get 933 Hz instead of 1000 Hz - descending pitch
 

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