RD Performance vs. Weather

[crisptito]

Just curious if there has been a study on the performance of RD based on climate conditions. Maybe the GOL have done this? I am in Alabama and most of our year we are in a muggy and humid airmass (thanks Gulf of Mexico). I have noticed a signficant decrease in the sensitivity and range of my V1 when it is warm with high humidity vs over the winter in dry, cooler air. If I had to guess, I would say that detection range and sensitivity is 10-15% better in conditions where external temps are below 80 and relative humidity is less than 60%. I think the humidity/dewpoint has more to do with it than the temps though.

So it leads me to believe that folks who live out in the southwest US might be getting the best performance out of their RD's. Anyone else have thoughts on this? Would love to get Jimbonzzz opinion.

[stevo1569]

Ok well I live in South West Florida so in the summer i can get 95% humidity and in the winter it will get back to the 10-15%. I can safely say the humidity doesnt affect it in any noticeable way.

Now if you're talking about rain, smoke, etc. That will affect the radar range of the LEO and the detection range on your RD. These conditions will affect LIDAR way more than radar. Since LIDAR is only based on optics, LIDAR guns are normally operated in clear conditions.

Hope that helps :)

[stlcardsfan]

Just curious if there has been a study on the performance of RD based on climate conditions. Maybe the GOL have done this? I am in Alabama and most of our year we are in a muggy and humid airmass (thanks Gulf of Mexico). I have noticed a signficant decrease in the sensitivity and range of my V1 when it is warm with high humidity vs over the winter in dry, cooler air. If I had to guess, I would say that detection range and sensitivity is 10-15% better in conditions where external temps are below 80 and relative humidity is less than 60%. I think the humidity/dewpoint has more to do with it than the temps though.

So it leads me to believe that folks who live out in the southwest US might be getting the best performance out of their RD's. Anyone else have thoughts on this? Would love to get Jimbonzzz opinion.Actually crisp amateur meteorology is my other "hobby". I don't know if I can tie it into this case but the relative humidity isn't the best way to measure moisture in the atmosphere. The dew point is. Air with more moisture is more dense and therefore can affect detection range on a radar detector. Also, I can see temperature possibly affecting range if radar transition ties into basic physics. Cold air is more dense than warm air (<-- ever wondered why the second floor of a building than the 1st), therefore I would think that a detector could perform better in warmer conditions. MEM-TEK may have to correct me.

[KnightHawk]

Just curious if there has been a study on the performance of RD based on climate conditions. Maybe the GOL have done this? I am in Alabama and most of our year we are in a muggy and humid airmass (thanks Gulf of Mexico). I have noticed a signficant decrease in the sensitivity and range of my V1 when it is warm with high humidity vs over the winter in dry, cooler air. If I had to guess, I would say that detection range and sensitivity is 10-15&#37; better in conditions where external temps are below 80 and relative humidity is less than 60%. I think the humidity/dewpoint has more to do with it than the temps though.The V1's weakness is heat within the unit itself. If you don't point one of your airvents to the unit, the unit overheats. I had one occassion back in 2005 when I just got my V1 that it did not even alert to LEO just across the street. We were waiting for our lights to go green. This has also been seen during GOL's test in Arizona were the V1's performance got worse after exposure to prolong heat. It has been my observation that when the V1 is cooled properly, performance is exceptional. As far as atmospheric factors, I'll leave it to the pros.

[whiterabbit05]

Heat is the #1 killer of all electronics, if you don't drop it in a pool first.

[crisptito]

Not really talking about heat of the unit here. V1 stays pretty cool with the a/c cranked. I agree with Clay that it seems as though the more moisture in the air, the smaller the range of detection. It would be interesting to see what hampers range more: dewpoint or RH (I am a weather nerd too). I could see detection being decreased on a cooler morning (moist air) with high relative humidity the same amount as a hotter day with increasing dewpoints. Whatever way you look at it, I feel strongly that performance is much better on cooler days with low dewpoints and RH.

[KnightHawk]

I think you have to question the effects of weather with regards to radar's ability to transmit rather than the receiving end or detector's end assuming that the radar detector is in good working condition because the receiver really depends on how the signal is transmitted. If transmission is hampered, expect that the receiver will also have a problem receiving the signal. We know that rain, snow and moisture has an effect to the radar's range and lidar's range.

Other than the heat build up issue with the V1, I don't see no other factors affecting it's ability to receive radar signals.

[stlcardsfan]

Not really talking about heat of the unit here. V1 stays pretty cool with the a/c cranked. I agree with Clay that it seems as though the more moisture in the air, the smaller the range of detection. It would be interesting to see what hampers range more: dewpoint or RH (I am a weather nerd too). I could see detection being decreased on a cooler morning (moist air) with high relative humidity the same amount as a hotter day with increasing dewpoints. Whatever way you look at it, I feel strongly that performance is much better on cooler days with low dewpoints and RH.
You should probably ask James Spann (http://alabamawx.com) down there what he thinks ( I know he's the popular weather guy in B-Ham). ;)

[crisptito]

You should probably ask James Spann (http://alabamawx.com) down there what he thinks ( I know he's the popular weather guy in B-Ham). ;)

Ha! Got his bobble head sitting on my desk as I type this! James is the freaking man when it comes to severe weather. I am actually one of the weatherwatchers for James in north Shelby county.

Good point Nighthawk. That is probably the direction that I should look at this from. The signal source fluctuates while my RD functions at a constant level.

[Stealth Stalker]

Although not necessarily *exactly* the same thing, just think of what happens when the clouds (moist air) roll in over your satellite dish. You lose your signal. There is a proven effect on humidity on RF propagation. But to be more specific, I am unaware of any enthusiast tests to quantify the effect on police radar.

[KnightHawk]

What does the satelite receiver say? Lost signal. That's just a good example that the signal from the satelite is blocked by the clouds or heavy moisture. This is also seen when you operate radar in rainy weather. Transmission is blocked and deflected resulting to poor radar performance. The satelite dish is just a receiver like a radar detector. When a dish cannot capture a signal, it cannot broadcast a signal. Receivers depend on transmitted signals and not the other way around. A radar detectors performance is dependent upon it's sensitivity not by weather conditions or factors. Transmitted signal depends greatly in different weather conditions, terrain and RFI - radio frequency intereference.

[Stealth Stalker]

Agreed. That's why I said that it was not "exactly" the same thing. But the principle of RF attenuation by atmospheric conditions is similar, and would factor in to some degree.

[KnightHawk]

Another example here. You test 2 radar detectors, a V1 and a cobra against radar in the same weather condition. Which will perform better? The V1 or the cobra? Does the weather have to do anything with the ability of the V1 or the cobra to detect the signal? Or is it the V1's sensitivity that outperforms the cobra?

[FoolishOne]

You should probably ask James Spann (http://alabamawx.com) down there what he thinks ( I know he's the popular weather guy in B-Ham). ;)
Why are those people still on the beach?

[partsfreak]

A long while back I posted an observation that is similar to the OP.
I notices that my sensitivity was better in th morning when it was cooler and dropped of a litle later during the day once it got hot.
The average morning temps were in the mid 50s and it heated up into the high 70s to mid 80s in the after noon.
I noticed about 1/4 to 1/2 block difference in alerts. Not a big diff but noticeable.

[KnightHawk]

Check this out.

Radio Receiver Dynamic Range :: Radio-Electronics.Com (http://www.radio-electronics.com/info/receivers/dynamic_range/dynamic_range.php)