WXforum.net
Weather Station Hardware => Davis Instruments Weather Stations => Topic started by: Greg_M on June 21, 2018, 09:08:52 AM
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I've had my Davis for a few years now (Christmas present) and been waiting to put it up at the new house in New Mexico.
Finally got my tower up which will provide a place to mount it.
So I think today is the day.....
(http://www.datilcam.com/old%20glory.jpg)
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Wow, nice tower.
So how are you getting the equipment on it? Assume the anemometer on top and ISS near bottom?
Do keep us updated with your progress.
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I climb it....
(http://www.datilcam.com/flag1.jpg)
I am trying to keep an area near the top clear of things, so I think I will put the anemometer near the cell phone antenna.
Probably have the rest at about 10'.
I still have an antenna to put up on top and I don't want to be stepping on stuff as I put it up.
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Well that was pretty easy.
The anemometer is at about 30'. I had to put it on the NW leg of the tower so I could get it to point north.
Iss is at 11'.
Now I can fiddle the computer interface into working.
(http://www.datilcam.com/davis.jpg)
Looks like the fire down towards Reserve is kicking up again.
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What antenna are you putting up? I see that you are a Ham also. Probably a nice beam?
What is the small Yagi, is that 33cm? Is it for a Davis repeater, or something else in the 900MHz band? (unless I can't judge the size correctly)
73, Greg H. (the other, other Greg) KE8DAF
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I bought a used Hygain TH6DXX (3 band 10-15-20) and I am refurbishing it before I put it up.
The small yagi is a cell phone antenna. It picks up the distant signal and sends it to an indoor amp and then to an indoor antenna. We don't get cell with out it.
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Got my weather station running and on the net at this temporary location
http://www.oldthomasplace3.com/weather/ (http://www.oldthomasplace3.com/weather/)
Once I get the webcam running I will be moving some stuff around, but for now you can see it at that link location.
VP2 → Cumulus → Website
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This is a dream installation for weather station owners... Any reason why you didn't bring the ISS down to 4 or 5 ft? It would be easier to clean the rain bucket and general maintenance.
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Concerned about radiation from the 10 yard chunk of cement that is the base.
Also don't wanted to think about curious hands, although way out here I have few concerns that it will be an issue.
I have a step ladder that I can reach it from. It's only at 11'.
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This is probably exactly accurate, but...
Barometer 22.977 in
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I'll have to do some searching and try to figure out how to calibrate it.
I just wanted to get it up and running.
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Concerned about radiation from the 10 yard chunk of cement that is the base.
Also don't wanted to think about curious hands, although way out here I have few concerns that it will be an issue.
I have a step ladder that I can reach it from. It's only at 11'.
I don't really think it is enough cement to worry about... If it was an airport runway of cement that would be another story. I think I would bring it down, but that is just me over thinking it perhaps, but I do know that temperature and humidity vary moving higher, and often the thermometer will read higher moving up in elevation. Humidity will be lower most times. If you have children around that might try to damage it, I would leave it be.
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I had not set the Lat-Long-El on the Davis.
That made a difference!
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I had not set the Lat-Long-El on the Davis.
That made a difference!
Barometer 22.977 in
Barometer 29.517 in Rising Rapidly 2.182 in/hr
:-) :-) :-) :-) :-)
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Concerned about radiation from the 10 yard chunk of cement that is the base.
Also don't wanted to think about curious hands, although way out here I have few concerns that it will be an issue.
I have a step ladder that I can reach it from. It's only at 11'.
I don't really think it is enough cement to worry about... If it was an airport runway of cement that would be another story. I think I would bring it down, but that is just me over thinking it perhaps, but I do know that temperature and humidity vary moving higher, and often the thermometer will read higher moving up in elevation. Humidity will be lower most times. If you have children around that might try to damage it, I would leave it be.
I discovered a radiation problem at my astronomy shack out of Bend, OR a few years back.
I had an 11'x11' cement pad and pier I would set my telescope up on to do astrophotos. I noticed the heat radiating from the pad when I went out to mess with the scope, so I tried throwing a bucket of water on the pad to cool it at dusk. It worked to a degree (ha!).
It was then that I noticed that all modern professional observatories are built up off the ground to get out of "ground effect" heat. The reason we moved to here is to do astronomy and my new observatory will be at about 20'.
The thermal mass of this 10 yards of cement is considerably more than the little pad in OR.
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I had not set the Lat-Long-El on the Davis.
That made a difference!
Barometer 22.977 in
Barometer 29.517 in Rising Rapidly 2.182 in/hr
:-) :-) :-) :-) :-)
Pretty dramatic, eh?
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I wonder if you can scrape enough gravel/dirt/sand/rocks from the surrounding area and cover over the exposed concrete pad?
That way it would be identical, actually IS, to the surrounding area, and it would be no different than driving a post in and securing your temperature/humidity sensor to that.
I know you don't want anything dark or heat absorbing but in this case, rock is rock.
I think that a few inches of stuff over the concrete would also effectively isolate it from the sun's energy, heating up in the day and then cooling more slowly at night.
I know a neighbor here in the midwest greenery galore and not much of your surface, who puts big rocks for landscaping purposes in his garden, only to discover that they cool slowing after the sun goes down providing a wonderful warmer niche for his hostas. You'd being doing the opposite by keeping the huge mass at ambient temperature.
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Not a bad idea
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Concerned about radiation from the 10 yard chunk of cement that is the base.
Also don't wanted to think about curious hands, although way out here I have few concerns that it will be an issue.
I have a step ladder that I can reach it from. It's only at 11'.
I don't really think it is enough cement to worry about... If it was an airport runway of cement that would be another story. I think I would bring it down, but that is just me over thinking it perhaps, but I do know that temperature and humidity vary moving higher, and often the thermometer will read higher moving up in elevation. Humidity will be lower most times. If you have children around that might try to damage it, I would leave it be.
I discovered a radiation problem at my astronomy shack out of Bend, OR a few years back.
I had an 11'x11' cement pad and pier I would set my telescope up on to do astrophotos. I noticed the heat radiating from the pad when I went out to mess with the scope, so I tried throwing a bucket of water on the pad to cool it at dusk. It worked to a degree (ha!).
It was then that I noticed that all modern professional observatories are built up off the ground to get out of "ground effect" heat. The reason we moved to here is to do astronomy and my new observatory will be at about 20'.
The thermal mass of this 10 yards of cement is considerably more than the little pad in OR.
Hello to a fellow Astrophotographer and Davis owner!
William
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I've used outdoor carpet before lighter shade like grey marine grade for mold and mildew resistance.
Not sure I would worry about such a small slab provided sensor is mounted at top of suggested height 6'. Nice setup BTW.
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Greg,
Rohn 45G is marvelous stuff.
I have a whole bunch of weather stuff added to my tower, first put up solely for the ham radio stuff, and was well planned for that.
Then the local TV stuff was added when HDTV came on and we being 90 miles or so from the Twin Cities added some antennas and preamps. The sensors and pyranometers came on later, and I wished I had the energy to climb any more and go up to strip the old stuff off, but it works for me. I got a few more things to get up then be happy until the next big thing comes along.
Keep posting the pix.
Dale
K9ELD
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Greg,
Rohn 45G is marvelous stuff.
I have a whole bunch of weather stuff added to my tower, first put up solely for the ham radio stuff, and was well planned for that.
Then the local TV stuff was added when HDTV came on and we being 90 miles or so from the Twin Cities added some antennas and preamps. The sensors and pyranometers came on later, and I wished I had the energy to climb any more and go up to strip the old stuff off, but it works for me. I got a few more things to get up then be happy until the next big thing comes along.
Keep posting the pix.
Dale
K9ELD
Thanks Dale, nice collection up there.
This tower is actually 55g. I found it on Craigslist. It was unused. A guy had bought it and never put it up. Couldn't pass it up.
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Better yet! How far down did you bury it? I have guys on mine but am only 4' into the ground.
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I got 4 sections from the guy on Craigslist.
One section and a little bend in the most end rung so I used that for the bottom piece and buried half of that section. The Rohn engineers give pretty exact instructions on the the hole size and rebar (#7).
I figured they sell those 5' sections for burying so I went with 5' of the first section with the bent rung.
I'm not real good with my tractor so the hole got a bit bigger than they called for. Instead of close to 6 yards it wound up being closer to 10.
Oh well. I always tend to overbuild.
(http://www.datilcam.com/tower1.jpg)
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That tower's not going nowhere. I see where the slab could be a big heat sink now.
My suggestion is to have weather station off to side somewhere and just use tower for anemometer. Rain gauge needs mounted at about 3' elevation anyway.
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That tower's not going nowhere. I see where the slab could be a big heat sink now.
My suggestion is to have weather station off to side somewhere and just use tower for anemometer. Rain gauge needs mounted at about 3' elevation anyway.
According to the Rohn engineers it's supposed to be good for 100 mph wind with a 7 sq ft load at the top.
So far, according to the Davis, our gusts have been at about 33 but we do have bigger winds on occasion.
I put the tower 45' from the house and it is only 35' tall.....just in case.
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Great project. Yet, if that amount of concrete is below the surface and covered with natural material, the whole thing is 'natural material'. There looks to be an appreciable amount of rock there in the ground anyway, which would have a thermal mass of it's own, but not if protected from direct absorption of the sun by being covered.
In any event, you will have a built in FARS if you have at least some wind all the time.
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That tower isn't going anywhere. the ideal height for the ISS is 5 feet above the surface, but the wind can be as high as you care. Just thinking... in about 100 years some geology guy is going to dig there and wonder WTF? is this thing . Write a paper and be world famous
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Just before the pour.
That's #7 rebar which is pretty close to an inch in diameter.
WTF indeed!
:grin:
(http://www.datilcam.com/tower2.jpg)
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We've been 'out west' a few times. The ground in many places seems to be rocky. I look at the high tension lines carrying power over valleys and over passes and wonder how the world did they set those poles!
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You mean there's dirt with out rocks?
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Great tower and that thing sure isn't going anywhere! I'm getting ready to expand my Koi pond this fall when it cools off a bit, could use your help bending the #6 rebar (3/4 inch dia) I put in the first pond and surrounding foundation/waterfall. =D>
I see you've already addressed the height of your ISS. If you haven't run across the dot gov website yet, that's the siting resource many use; albeit, most are unable to fully comply with:
https://www.weather.gov/media/epz/mesonet/CWOP-OfficialGuide.pdf (see page 31)
https://www.weather.gov/media/epz/mesonet/CWOP-Siting.pdf (see page 6 for a laugh)
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Ok, I'll lower it to 6' but no lower.
I hate walking in to things.
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Greg,
There's the official way and then there's the practical way.
If it is already up, that carries a lot of weight in your decision. Being wireless, its easy to move, but time on the tower is hard on my feet and having a ground crew is sometimes hard to get in place.
I think the most telling tale is you saying you had almost constant breezes or zephyrs depending upon the day.
The natural mixing and movement is going to cancel out any stratification that may occur otherwise. The guidelines say wind at 30' up or so, and there are a lot of papers from universities showing the wind speed slowing caused by the earth's surface, and this makes sense, but it is tough to get something that high, not whip around, and yet be able to be 'easily' taken down. Haven't been able to find a sky hook at at flea markets lately.
I think the height above ground was chosen for, well, the observer's height. I recall being envious of the white slatted shelters that we'd see at ranger stations or DNR offices, all on stilts which my dad joked was to make it hard for snakes to curl up inside them.
I'll look to see if there are the same kind of graphs for variation in temperature with height the same as the wind speed ones that I mentioned. But standards ARE standards and if you go too far from the expected, there is going to be avoidable variation. I know that of the many thermometers and humidity sensors I have, some are differing by a couple degrees and 20% depending on sun, wind, how much vegetation is growing, whether it rained and the underlying leaves are soaked, and so on. Wind is a great equilibrator, mixing things up a lot.
I'd probably not go to too much trouble, but the little battery may need changing once in awhile, but you have a good safety harness for climbing. And I don't see many maple or oak trees for plugging up the rain collector as much as my woods does.
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I can find plenty of stuff on how the temperatures drop as you go up, thousands of feet, that is.
The only thing I've found was this, pasted below, which implies that the stations have three temperature sensors, and they look for them to be within 0.3 degrees C of each other, do averages and all sorts of stuff with the data loggers.
I'd like to have them put one in my back yard!
"Surface Air Temperature
Each USCRN station has three thermometers which report independent temperature measurements each hour. These three observed temperature value are used to derive a single official USCRN temperature value for the hour. This single value is sometimes a median and sometimes an average of various combinations of the three observed values, depending on information about which instruments agree in a pairwise comparison within 0.3°C. Each station transmits the three independent observed values; the computation of the official USCRN temperature value is done after these values arrive at NCEI. The discussion below describes the details of the three observed values.
Each station has three Thermometrics platinum resistance thermometers, each of which is housed in its own Met One 076B 7308 aspirated solar shield. Each thermometer measures the temperature (in degrees Celsius) every 2 seconds. Every 5 minutes the station datalogger computes the average of these 2-second values, giving 12 5-minute averages for each thermometer. Standard deviations are also calculated for each thermometer. Finally, a moving 5-minute average displaced 10-seconds at a time is used to determine the maximum and minimum 5-minute periods ending within the hour in question.
In addition to the thermometer values, the station also measures the speed of the fan in each aspirated shield. As the shield's fan rotates, a contact closes and generates a pulse twice per rotation. The datalogger counts these pulses every two seconds. Every hour these 2-second values are averaged to obtain an average number of pulses per second for the hour. The hourly data stream from the station thus include the average pulse rate per second for each of the three sensors. The actual speed of the fan in revolutions per second is half the pulse rate."
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You can see what our tax dollars brought for this system with the pictures in this pdf
http://www1.ncdc.noaa.gov/pub/data/uscrn/documentation/site/photos/stationsbystate_lores.pdf
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You can see what our tax dollars brought for this system with the pictures in this pdf
http://www1.ncdc.noaa.gov/pub/data/uscrn/documentation/site/photos/stationsbystate_lores.pdf
Nice link, first thing I noticed was all the DFIR (Double Fence Interna-onal Reference) rain gauge shields.
Studies show DFIR are superior especially for snow catch compared to the single alter windshield. 130mm year more precip caught at test site and over 300mm more vs no shielding at all. The base amount DFIR caught around 820mm total.
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Ok got it lowered.
As long as I don't wear a hat, everything will be fine.
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In the site specs, despite having the Obsessive compulsiveness to have not one, not two, but THREE temp sensors and average them and all, that they chose to have the wind speed at 2 meter height. Very odd.
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In the site specs, despite having the Obsessive compulsiveness to have not one, not two, but THREE temp sensors and average them and all, that they chose to have the wind speed at 2 meter height. Very odd.
Is odd I guess, only thing I can think of its environmental only and not aviation oriented where the 10 meters came from.
I do like the triple redundancy, my almost 4 decade career as operator at supercritical power plant, our critical instruments were triple redundant where 2 of 3 needed to match.
Come to think of it I'm still doing the same with my personal weather station with 3 different ISS's. ;)
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If I recalll the orbiter on the space shuttle system had 5 computers, all voting as to their value. The three that were closest were taken as the commands or accuracy of measurement.
If you look at some of the other information about these sites, the rain gauge is a weird thing. It is a bucket which is suspended by three sensors which weigh it when commanded. They use something called a vibrating wire method (gotta look that one up yet) and weigh it several times. I don't know how or when it automatically dumps, but I've heard of glass tubes, sticks in tubes, tipping buckets, doppler radar estimates of rate and quantity, Vaisala drop impact measurement, capillary tubes, and siphons like RM Young stuff. I guess one could put on dry clothes, stand in the rain and weigh yourself too or how much the long haired dog gained in weight while out, but this one is a new one to me.
https://www.ncdc.noaa.gov/crn/instruments.html
http://geonor.com/live/products/weather-instruments/t-200b-weather-precipitation-rain-gauge/
And my wife wonders what I do with all my time and in front of the computer.
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Well it's been about 6 mos since the weather station/tower went up.
Finally got my permanent webpage for it up, although I haven't got the webcam running yet. (Too cold to climb towers)
I did go about half way up the tower and take a picture of what the webcam will be looking at and got the link to the weather page at the bottom.
http://www.datilcam.com/ (http://www.datilcam.com/)
I'm working on the webcam currently (inside the house).
Turns out the highest wind gust has been 58mph and it got up to 98.5° F.
Records so far.....
http://www.datilcam.com/weather/record.htm (http://www.datilcam.com/weather/record.htm)
Hopefully I will get the webcam up in the next month or so....Don't want to rush in to anything.
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Awesome setup and gorgeous view you have there, Greg.
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I did go about half way up the tower and take a picture of what the webcam will be looking at and got the link to the weather page at the bottom.
http://www.datilcam.com/ (http://www.datilcam.com/)
For those of us that have this view and no more than a few hundred feet out https://map.bloomsky.com/weather-stations/gqBxp6apnJSnoJim
dito John
Enjoy,
Paul
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Awesome setup and gorgeous view you have there, Greg.
Thank you.
They do call it "The Land of Enchantment" and I find that people either love it or hate it.
We love it.
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Broke our previous wind speed record the other day with a new wind speed record of 81 mph.
http://www.datilcam.com/weather/thismonth.htm
I was curious about how wind speeds are figured so I looked around on the net and found this.....
On the Beaufort wind scale......
Near-gale force winds are 28 to 33 knots. (32.22 to 37.97 mph)
Gale force winds are 34 to 40 knots (39.13 to 46.03 mph)
Strong gale force winds are 40 to 47 knots. (46.03 to 54.09 mph)
Winds above 47 knots and below 64 knots are storm winds. (54.09 to 73.65 mph)
Sixty-four knots and above are hurricane force winds. A wind, not necessarily a hurricane, having a speed of more than 72 miles per hour (32 m/sec): the strongest of the winds.
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Broke our previous wind speed record the other day with a new wind speed record of 81 mph.
http://www.datilcam.com/weather/thismonth.htm
I was curious about how wind speeds are figured so I looked around on the net and found this.....
On the Beaufort wind scale......
But please remember that the Beaufort scale was originally developed only for use at sea, where wind speeds tend to be more sustained and less gusty in nature. The way that this is applied nowadays is that the Beaufort scale should only be used in relation to mean wind speeds (10-minute mean is the preferred measure I think, but 2-min may substitute).
So it's really not correct to talk about eg a Force 7 gust because gust speeds simply don't relate to Beaufort, you need to be checking the maximum mean/average speeds.
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Awesome setup and gorgeous view you have there, Greg.
Thank you.
They do call it "The Land of Enchantment" and I find that people either love it or hate it.
We love it.
We have visited NM numerous times over the years. I subscribe to New Mexico magazine and I always get a kick out of the "One of our 50 is missing (https://www.newmexico.org/nmmagazine/heart-of-nm/one-of-our-50-is-missing/)" page.
We visited the VLA (has it already been almost 19 years?), but have spent more time in the Las Cruces and Alamogordo areas. I really love the White Sands National Monument (https://www.nps.gov/whsa/index.htm).
Greg H.
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We originally bought property in Cloudcroft (up above Alamogordo in the mountains) and then a couple years later found the property we finally built on here in Datil.
We would fly in to El Paso (from Seattle) and I always liked the humor of the message "Eat Pecans" that a farmer had spelled out in 200' letters with Pecan shells under the flight path, in Las Cruces.
The VLA is about 20 miles (as the crow flies) from our house, to the east.
I have run in to instances of people thinking we are located in Mexico a couple times.
I usually just say "We are the state between Texas and Arizona". :-)
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WOW, just wow......
Looking at the grass out there, even that would be a problem, i take it grassing a nice square area around it and maintain it is out of the question? thats what i would do, but its all down to preference, what about a few square meters of artificial grass, thats what the UK met office uses now, keeps maintenance to a minimum...
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You'd really have to work at green lawn grass out here.
It can be done but it's a chore.
The UV up here is intense. (7,350')
Maybe with a sprinkler system....but no doubt it would freeze in the winter.
We're in a zone 5 climate.
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You wouldnt need it in the winter :)
How about artificial, its not as good as grass but it must be ok seen as the UK MO uses it :) its a tad expensive but ya dont need much really 3 or 4 sqm?
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I wonder how the UV would be on it?
I'd have to figure a way to keep the AstroTurf from blowing down to the neighbors.
I still have the observatory to build and I was thinking of coating the exposed concrete with the paint they use around swimming pools to keep your feet from getting cooked?
We do have our environmental problems.
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I should think the turf would be UV resilient for sure, and its normally pegged down some how i think, its also dependent on the type you get, some are held down by the weight of that and the sand but as yours will be a relatively small section, then deffo peg it :)