Spread spectrum KA band radar - does it exist?

[justin81]

Several years ago, I was having a conversation with a police officer about radar. He was explaining that his department had "new" superwide KA band radar guns that had the ability to hop around on five different frequencies on the KA band to avoid detection. He more or less implied that radar detectors were totally obsolete against this gun because it put out the signals so quickly that the filtering circuitry in detectors would reject the brief signals as false alarms.

First of all, does this really exist?

Second, if it does, is it detectable by current detectors?

Thanks,
Justin

[amoney]

No it does not.

It was thought of but never implemented.

In the end it basicly came to be that there were different Ka bands used thus the detector took longer to sweep the wide band to search for the possible freq used, making it harder for the detector to detect was the idea, but RD manufactures trumped the police radar by making a detector work. Didn't skip a beat.

It is amazing how little officers know about the technology.

[MEM-TEK]

...It is amazing how little officers know about the technology [that they use].

I'm rather glad that they don't know!

[amoney]

...It is amazing how little officers know about the technology [that they use].

I'm rather glad that they don't know!

:wink:

[bart99gt]

Stalker toyed with the idea some years ago, but as was mentioned, nothing ever came about it. I don't know if any prototypes or other working test units ever appeared or if it was just some rumblings from their R&D department.

[ahmadr]

On a side note,
spread spectrum != frequency hopping

Frequency hopping is relatively easy to detect.

Spread spectrum (CDMA) can become very hard to detect, but implementing it (on Ka) is hard/costly too.

[Won Hunglo]

Great idea but 20 years too late.

[JonnyZero]

On a side note,
spread spectrum != frequency hopping

Frequency hopping is relatively easy to detect.

Spread spectrum (CDMA) can become very hard to detect, but implementing it (on Ka) is hard/costly too.

Why would CDMA be difficult to detect? My old POS Sprint phone managed to sniff it out okay. As long as I am not trying to decode the digital message, and am simply trying to sniff out transmission in the freq range, why would there by any difficulty?

I fail to see why a police radar needs digital encoding; the dopper effect is purely analog, and takes very little bandwidth to operate. At 34.7 GHz, 100MPH causes 10KHz of shift, they have got 2.6 GHz of bandwidth to play with.

[Lucky225]

On a side note,
spread spectrum != frequency hopping

Frequency hopping is relatively easy to detect.

Spread spectrum (CDMA) can become very hard to detect, but implementing it (on Ka) is hard/costly too.

Why would CDMA be difficult to detect? My old POS Sprint phone managed to sniff it out okay. As long as I am not trying to decode the digital message, and am simply trying to sniff out transmission in the freq range, why would there by any difficulty?

I fail to see why a police radar needs digital encoding; the dopper effect is purely analog, and takes very little bandwidth to operate. At 34.7 GHz, 100MPH causes 10KHz of shift, they have got 2.6 GHz of bandwidth to play with.

Agreed and we all know what happens when CDMA misses part of the encoded message, the audio skips, and this skipping probably would produce false readings

[KnightHawk]

On a side note,
spread spectrum != frequency hopping

Frequency hopping is relatively easy to detect.

Spread spectrum (CDMA) can become very hard to detect, but implementing it (on Ka) is hard/costly too.

Why would CDMA be difficult to detect? My old POS Sprint phone managed to sniff it out okay. As long as I am not trying to decode the digital message, and am simply trying to sniff out transmission in the freq range, why would there by any difficulty?

I fail to see why a police radar needs digital encoding; the dopper effect is purely analog, and takes very little bandwidth to operate. At 34.7 GHz, 100MPH causes 10KHz of shift, they have got 2.6 GHz of bandwidth to play with.

Agreed and we all know what happens when CDMA misses part of the encoded message, the audio skips, and this skipping probably would produce false readings

X2 I think it only applies to radio frequency hopping like the LEO people use or when sending encrypted messages with a deciphering program. I don't think i will work when applying it on radar systems. If it's possible, it will be very hard and one unit can be costly.

All radar units sold today are already sufficient to counter all radar detectors with or without a spectre unit. What else do they need?