The Conservative Cave

Interests => Around the House & In the Garage => Topic started by: Gamle-ged on November 16, 2016, 09:35:40 PM

Title: Is your radar detector just a new-car detector?
Post by: Gamle-ged on November 16, 2016, 09:35:40 PM
Imagine the frustration of investing and installing a new radar detector only to discover that all it alerts you to is something installed in your car and every other new car within close proximity. The reason this is happening is that car manufacturers are installing collision avoidance and adaptive cruise control systems into new cars, which use radar or laser sensors, enabling the car to automatically sense its driving environment and to respond accordingly. Because many of these systems use the same radar and laser frequencies that police use, many radar detectors sold today are nothing more then new-car detectors.

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Due to the impact these anti-collision sensors have had on radar detectors, manufacturers have already stepped up to the plate to offer their own unique solutions to this increasing threat. Most notably, those companies include Stinger, Escort, and Valentine Research.

http://www.autoblog.com/2015/11/17/radar-detector-new-car-detector/

The last time I bought a new detector was some years back when I approached one of those "Your speed is" electronic signs and it accurately told me my speed, but my radar detector stayed silent. A check of the internet told me that there was a then-new Ka band frequency being used in police radar! Might be getting near time to buy a newer (more expensive) unit...


Title: Re: Is your radar detector just a new-car detector?
Post by: J P Sousa on November 17, 2016, 09:25:47 AM
Thirty years ago I had a radar detector that only beeped when I passed a supermarket but that did not stop a cop from giving me a ticket for having one.  :censored:
Title: Re: Is your radar detector just a new-car detector?
Post by: SVPete on November 17, 2016, 10:40:58 AM
A key problem is that microwave frequency bands are very broad. The Ka band, for example, is from 26.5 GHz to 40 GHz. That's extremely broad, and one could use a vast number of individual frequencies in that band, simultaneously in the same geographic area without individual users interfering with each other. So your radar detector has to scan the full band. Unless it's very discerning, it can't tell whether the sensed signal is from a police radar, an adjacent car, a supermarket with an anti-theft shopping cart wheel locking system, or a Predator drone. Scanning an entire spectrum (or a broad segment) is time consuming, and analyzing sensed signal to identify them is even more time consuming. The latter is also expensive.
Title: Re: Is your radar detector just a new-car detector?
Post by: SPYDER on April 19, 2018, 05:18:34 PM
A key problem is that microwave frequency bands are very broad. The Ka band, for example, is from 26.5 GHz to 40 GHz. That's extremely broad, and one could use a vast number of individual frequencies in that band, simultaneously in the same geographic area without individual users interfering with each other. So your radar detector has to scan the full band. Unless it's very discerning, it can't tell whether the sensed signal is from a police radar, an adjacent car, a supermarket with an anti-theft shopping cart wheel locking system, or a Predator drone. Scanning an entire spectrum (or a broad segment) is time consuming, and analyzing sensed signal to identify them is even more time consuming. The latter is also expensive.

  Today the only band you really need to monitor is the Ka band.  Maybe around town they might use laser, but most police are lazy and just use the Ka band.  And the Ka band for police radar is much narrower than you posted. They use to use  33.4 - 36.0 GHz. In 1983 the FCC allocated the spectrum from 34.2 - 35.2 GHz for police radar use.