Author Topic: AWEKAS  (Read 1296 times)

Blicj11

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Re: AWEKAS
« Reply #15 on: August 28, 2017, 06:42:58 AM »
I tried to explain to AWEKAS that I am reporting pressure adjusted to sea level. They sent me the following link. After looking at their link, I still think I am reporting the correct pressure. Am I missing something?

https://www.awekas.at/for2/index.php?page=Thread&threadID=15235&highlight=pressure
Blick


xairbusdriver

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Re: AWEKAS
« Reply #16 on: August 28, 2017, 02:34:04 PM »
I fear you may never 'convince' AWEKAS of the quality of your data until they have several other stations at higher elevations in your vicinity. You are probably fighting the 'law of averages', not to mention non-standard conditions for computing the value they want. Your terrain could be affecting the air temps in your location. Maybe you could offer the NWS an acre to place one of their reporting/recording systems!

When I started flying, high altitude vertical spacing was based on 2,000' separations. Now, using GPS, they use 1,000'! Too much variation in instrument capabilities, installation and air conditions! "Computers/satellites never fayle!"

elagache

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But, but, but, . . . . (Re: AWEKAS)
« Reply #17 on: August 28, 2017, 10:39:34 PM »
Dear Blick and WeatherCat troubleshooters,

In addition, when I compare my pressure readings to the SLC Airport, I am pretty much where I should be given the altitude difference between here and there and I know they adjust for sea level.

But, but, but, . . . . . that is precisely what is not supposed to happen!  You have entered your elevation into your Davis console, therefore it should be reporting barometric pressure at sea level (that's the whole point of putting in your elevation.)

As JosBas says:

I just checked the AWEKAS site and I see weather-stations in Switzerland at 2,800m (±9,100 ft) reporting 1014hPa. A nearby station at 215m (700ft) is reporting practically the same value so they MUST be using the same reference altitude (= sea level).

So it stands to reason, your station isn't calibrated correctly if you are close enough to the Salt Lake City airport that the pressure should be the same.  The alternative explanation is that you far enough away that the pressure is different because the air masses are different.  If Salt Lake City is close enough that the values are the same, then something is out of whack with your David barometer.  In that case, perhaps you should use the WeatherCat adjustments so that your station indeed is reasonably close to the Salt Lake City values.

Sorry this is such a mess, but it should possible to resolve this such that AWEKAS is satisfied.

Keep pluggin' on this one!

Cheers, Edouard

Blicj11

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Re: AWEKAS
« Reply #18 on: August 30, 2017, 04:32:52 AM »
Special thanks to Edouard and Jos for patiently helping me understand this issue. My brain has finally kicked into gear and I now understand what you are both saying.

Because the Davis formula for correcting air pressure for altitude does not precisely match the NOAA formula, entering my altitude into the console does not quite allow my pressure to align with the SLC Airport. Re-reading your posts, plus re-reading the AWEKAS email, plus re-reading the calibration section in the Davis manual finally combined to turn on the light bulb in my head.

In addition to the altitude adjustment, I simply calibrated my console slightly to match the Metar data from the airport. I prefer to calibrate the console because i don't like seeing one number on the console and a different number in WeatherCat. I'll watch this over the next few days and see how it tracks. I have been under reporting my pressure by about 0.26 inHg, which also explains why I have never been able to pass the CWOP quality control check for pressure.

Maybe my scores in quality weather data contests will now improve. I have already proven that standardized tests don't accurately measure how brilliant I am, but there may yet be hope for me in backyard weather station circles.

Thanks again for helping me see the light (at altitude).
Blick


xairbusdriver

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Re: AWEKAS
« Reply #19 on: August 30, 2017, 02:39:16 PM »
Congrats, Blick, it takes a big man to admit recognizing an error in understanding. You've encouraged me to take another look at how my station is working and reporting. Might even join AWEKAS!

elagache

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Let us know if this does the trick. (Re: AWEKAS)
« Reply #20 on: August 30, 2017, 10:44:58 PM »
Dear Blick, X-Air, and WeatherCat station calibration adjusters,

Because the Davis formula for correcting air pressure for altitude does not precisely match the NOAA formula, entering my altitude into the console does not quite allow my pressure to align with the SLC Airport.

This is really quite interesting.  I would assume that it requires a significant elevation for the difference to be noticeable.  I wonder why Reinhard hasn't had this problem as well.

In addition to the altitude adjustment, I simply calibrated my console slightly to match the Metar data from the airport. I prefer to calibrate the console because i don't like seeing one number on the console and a different number in WeatherCat. I'll watch this over the next few days and see how it tracks. I have been under reporting my pressure by about 0.26 inHg, which also explains why I have never been able to pass the CWOP quality control check for pressure.

Let us know if indeed that satisfies AWEKAS and CWOP!

Congratulations on your persistence bearing fruit!  ThU32:-)

Might even join AWEKAS!

Joining AWEKAS isn't quite as easy to do as most of the WeatherCat data upload services, but the instructions can be found on the WeatherCat Wiki:

http://wiki.trixology.com/index.php?title=Automatic_Weather_Map_System_(AWEKAS)

Cheers, Edouard  [cheers1]

xairbusdriver

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Re: AWEKAS
« Reply #21 on: September 02, 2017, 03:55:42 AM »
After skimming the data quality suggestions and the recent problems in this thread, I doubt I will register at AWEKAS. It would probably just be more work for their quality assurance computers and end up not being useful for them. With the anemometer on the roof, I don't know exactly how high above the highest ridge without climbing up there. And there is no way I could have 40 meters between it and the trees and both of the houses on either side of me. Nor do I even have 20 meter diameter of open space anywhere on my lot for the temp sensor, much less the 30 meters for the rain gauge! I do have ~200+ acres behind our lot, fortunately, I do not own or pay the taxes on it! [lol]

If there is as much outward growth in the trees in my backyard as I expect, I may have to cease providing any data to CWOP, also. [rolleyes2]

Oh well...

Felix

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Re: AWEKAS
« Reply #22 on: September 02, 2017, 10:44:42 AM »
Exactly the conclusion I came to years ago, X-Air. I am interested in what the weather is in/around my property given the topography which makes things like temp, humidity and wind measurements quite a bit different from a small regional airport some five miles away. I'm not going to artificially offset my measurements to match what the CWOP algorithms "think" I should be reporting. 

xairbusdriver

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Re: AWEKAS
« Reply #23 on: September 02, 2017, 03:04:53 PM »
Algorithms
Trust but Verify!

 ThU5:-)