APRS coverage in the USA:
Frank Perdicaro says in comments:
Urban heat island measurement via APRS.
Today I finished off my ham radio General license, and one of the topics covered was APRS. The APRS system lets one communicate identity, location, time, and other meta data. I think it should be possible to create an APRS-enabled temperature station.
With a dozen stations, it would be possible to have a dozen people cross an urban
area in parallel, as their position and temperature were automatically noted by
the APRS net. Use of a few dozen APRS volunteers could produce definitive UHI maps by driving the same routes repeatedly across many days.
Due to the robustness of APRS, this looks like an easy task. All that is required is the funding.
Here in Orange County, we could definitively debunk the validity of the county’s
three official temperature stations. One is at the largest airport, one on the roof of a fire station in an urban setting, and the third next to the AC exhaust of the Nixon Presidential Library.
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See all here. First congrats to Frank for completing his General License. I’m still a Technician Class, maybe time to move up. For those who don’t know :
Automatic Packet Reporting System (APRS) is an amateur radio-based system for real time tactical digital communications of information of immediate value in the local area. In addition, all such data is ingested into the APRS Internet system (APRS-IS) and distributed globally for immediate access. Along with messages, alerts, announcements and bulletins, the most visible aspect of APRS is its map display. Anyone may place any object or information on his or her map, and it is distributed to all maps of all users in the local RF network or monitoring the area via the Internet. Any station, radio or object that has an attached GPS is automatically tracked. Other prominent map features are weather stations, alerts and objects and other map-related amateur radio volunteer activities including Search and Rescue and signal direction finding.
APRS has been developed since the late 1980s by Bob Bruninga, callsign WB4APR, currently a senior research engineer at the United States Naval Academy. He still maintains the main APRS website. The acronym “APRS” was derived from his callsign.
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What Frank proposes has some merit, and this seems a good place to toss around ideas. It would provide for a separate “ground truth” of climate data, free from adjustments.
In fact, somebody has already invented an APRS thermometer, see here. It’s probably a bit crude for this application, but it is a proof of concept.
Isn’t that pretty much already in place?
http://www.findu.com/citizenweather/
http://www.beals5.com/wx/
http://www.davisnet.com/weather/products/weather_product.asp?pnum=06540
http://www2.fiu.edu/orgs/w4ehw/w4ehw-aprs.html
A coordinator (and cheerleader) for longterm climate data is likely in order, and there may be some commercial possibilities the Weather Shop could focus on, so
I’m sure there’s work to be done.
REPLY: Not for mobile yet, and it is not standardized. A lot of those weather stations in the network are junky Chinese knockoffs like the horrible Oregon Scientific WM918 and WMR968. The temp sensors are shonky and they have no useful IR shielding.
In order to make something like this work for a scientific purpose, it would have to be standardized and calibrated. Anything less is just like using NOAA COOP data.
This idea intrigues me. While I don’t currently have an APRS setup, it shouldn’t be difficult to put one together for the purpose. Once we could get the proper thermometer, the OM or myself (average age: retired) should be able to chauffeur it over a fixed route and time schedule for a year or two or whatever.
Anthony,
KF6TAR here. I do not have a APRS capable rig, but will be glad to upgrade and participate.
I’m a tech also, I got my license at 14…..I enjoy SWL more than talking but this looks like a convincing reason to get back into it….
“Here in Orange County, we could definitively debunk the validity of the county’s three official temperature stations. One is at the largest airport, one on the roof of a fire station in an urban setting, and the third next to the AC exhaust of the Nixon Presidential Library.”
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If debunking is the purpose, credibility will be an issue.
I would expect some differences in absolute temperature from place to place in Orange County, but I doubt the trends would differ significantly.
REPLY: Heh, lectures on credibility from the anonymous coward, Wren.
With so many smart phones with GPS now out there, it’s too bad there aren’t inexpensive Bluetooth thermometers available, so an app could run in the phone.
Anthony, it’s a great idea. Don’t you sell weatherstation gear as a sideline? Perhaps the community could sponsor the issuing of calibrated – standardized equipment to volunteers through you?
Wren says:
June 6, 2010 at 11:09 pm
“Here in Orange County, we could definitively debunk the validity of the county’s three official temperature stations. One is at the largest airport, one on the roof of a fire station in an urban setting, and the third next to the AC exhaust of the Nixon Presidential Library.”
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If debunking is the purpose, credibility will be an issue.
I would expect some differences in absolute temperature from place to place in Orange County, but I doubt the trends would differ significantly.
REPLY: Heh, lectures on credibility from the anonymous coward, Wren.
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If I use my real name, do I have to give up being polite?
Why limited to N. America?
I agree that you should sell the equipment. You have a clear idea what constitutes an acceptable product and it could easily catch on. Brass pounders have run out of things to talk about (except how we invented everything).
HAM operators are a very cooperative community always looking for ways to assist. It has a SETI ring to it with a much greater chance of finding something valuable. The equipment would make a great present for Father’s or Mother’s Day (VE3HUG). Sure – why not?
KUTGW (keep up the good work) WUWT.
Crispin
3DA0AC / VE3NLD
“Here in Orange County, we could definitively debunk the validity of the county’s
three official temperature stations. One is at the largest airport, one on the roof of a fire station in an urban setting, and the third next to the AC exhaust of the Nixon Presidential Library.”
Does the above imply there is already an official localised UHI temperature that is readily available? I think this idea sounds interesting but ideally it needs to be either matched to a official comparable record or to be done to a consistent standard that has proper validity and becomes an acknowledged record in its own right. In the case of the latter, whilst it is a useful record of ‘today’ it can’t be compared to what has gone in the past.
In my view I think UHI is a far greater and demonstrable problem than is CO2 induced AGW. As far back as the Roman period temperatures in urban areas were known to be several degrees warmer than the surrounding countryside which forced the leading citizens to flee Rome in the summer.
Whilst UHI has some benefit in winter to many Northern cities it will be the final straw in the summer and I think we ought to be looking at ways to mitigate it. That can’t be done until we know the extent of the UHi so this sounds a promising idea.
Tonyb
I’m still a technician, too.
Still, wouldn’t it be easier to just look at a couple tree rings? Hrm… Or maybe one carefully selected tree ring. We could attach a boring device and macro-zoom webcam to a radio-controlled mobile robot. That way we wouldn’t have to drive out of convenient Starbuck’s distance. It would be all IPCC approved sciency and stuff. 🙂
Excellent Idea. It would be nice to have some good data on several cities that let us settle the “Heat Island Effect” question without lots of hand waving instead of real science.
AnonyMoose says:
June 6, 2010 at 11:40 pm
With so many smart phones with GPS now out there, it’s too bad there aren’t inexpensive Bluetooth thermometers available, so an app could run in the phone.
You neglect to consider the obvious: Where do most people keep their cell phones?
Yep: In a pocket. You’ll be measuring skin temperature most of the time, and hot breath for the remainder!
In order to correctly measure temperature, the device needs to soak in the atmosphere for a considerable period of time in order to ‘normalize’ to that atmosphere.
Additional to that is the fact that the phone radiates energy every time it is employed to make a call, and that in itself nullifies its possible use as an accurate device to measure temperature.
Gail Combs says:
June 7, 2010 at 4:32 am
Excellent Idea. It would be nice to have some good data on several cities that let us settle the “Heat Island Effect” question without lots of hand waving instead of real science.
The idea is ‘nice’ in theory, but the execution of it falls flat for a number of reasons, not the least of which is that actually being ‘involved’ by moving around, amounts to influencing the readings.
In a previous post by Anthony, regarding the use of his temp sensors being attached to a moving vehicle, I pointed out that merely being in the environment which you’re wanting to measure taints the data. Think: Heisenberg uncertainty principle.
From the American Heritage English Dictionary:
—————————————————————————
uncertainty principle
n.
A principle in quantum mechanics holding that increasing the accuracy of measurement of one observable quantity increases the uncertainty with which another conjugate quantity may be known.
—————————————————————————
Placing you finger into a body of water to determine its temperature, will influence that temperature.
My suggestion then –as now– is to place some sensors at strategically FIXED locations such that there is a great degree of repeatability for those locations.
The whole idea there is to eliminate –as much as possible– any aspect of artificial influence.
You are microwaving the atmosphere!, kind of Radio Global Warmers 🙂
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Sorry, but I don’t see the advantage of using APRS. We could easily use a device with a thermometer & GPS that writes to a removable flash memory. Then simply upload to a web site at your convienence and you’re done.
Lyman Horne
KB7EZY
The main question I would have would be how to get accurate measurements from a semi-permanently vehicle-mounted sensor. Compromises would have to be made for wiring access, aerodynamics, shielding, etc. Might be OK for trends, getting decent absolution calibration is probably a loss on something installable on a vehicle without making it look like a VORTEX2 probe. Cost will also be an issue (upper bound is probably $50-100, or no ham will ever buy it).
The APRS format would have to have additional kludges to transmit temperature in a standard way so it’s tied to a mobile position report. Right now the standard telemetry frame does not uniquely identify the sensor’s position at the time of observation.
Mr. Watts,
Could the information from the Oklahoma Mesonet be of any help in this project?
According to their tab, they use (or have used) the following instruments:
Thermometrics Fast Air Temperature 2004-Present;
Vaisala HMP35C 1994-2003.
I think Kansas and Nebraska are developing a similar network. Here on the Southern Plains weather is of more immediate import than climate.
OK S.
I referred to a Bluetooth thermometer so the thermometer could be mounted on the car, with the wireless link to the phone. My smart phone already has a thermometer on the battery, but you just described why that is difficult to calibrate to air temperature.
Yes, I do know of Bluetooth serial adapters, but the cheap RS-232 thermometers only have 0.5°C resolution. There are industrial/laboratory temperature probes which are expensive. The Kestrel 4500/4500 NV Weather Meter isn’t cheap enough ($300-400) but does have 0.1° resolution and 1°C accuracy.
I suppose that because hams are involved, I should also point out another technological option for temperature measurement. An RFID chip with a temperature sensor, such as the MLX90129 can be polled by an RFID unit. Phones don’t have RFID readers, but RFID readers can work with Bluetooth/RS232 devices. I’m not sure of that chip’s precision; I suspect it’s around 1°C if I interpret the datasheet properly.
I don’t think that would help the debate at all. I have my own wx station reporting to the internet 24/7 (Lents Weather) and I know it doesn’t meet the standards for temperature reliability; unless one has at least a half acre of ‘pasture’ the UHI monster is going to rear it’s head. Very few people in the city have a half acre of ‘unimproved’ land available. (you notice that most of the Ham operators on the above map are in the city) All that would happen with the proposed network is add ‘noise’ to the data.
The link in my previous comment didn’t work here it is http://tinyurl.com/2eaox8a
I’ve never played around with APRS but I probably have 3 rigs that are APRS capable. The problem (as I see it) is the lack of a standard for temp measurement. I have a lousy Oregon Scientific WM968 system. I KNOW how inaccurate these are. What we need (Anthony) is a standardized device that is affordable, reasonably accurate, has wireless connectivity and USB compatibility to a PC (and preferably compatibility with AmbientWeather software). If it were available I’d play
N5UDH
David S. Van Dyke
This could be a world wide thing – the same packet nets obviously exist over here in Europe.
ps upgrade to Extra – Pete G4TNB
there is also http://aprs.fi/ (which ‘guesses’ you location from your IP address as well)
A nice mobile thermometer would be nice & why not ask WB4APR to add a temperature message to the APRS standard ? It does have added value in SAR circumstances so it may not be too much of an ask.
Might actually get me to finally build my tinytrack aprs module…
Since UHI seems to be decried; I would imagine that the UHI profiles of MANY different locations around the world would demonstrate it as a real effect; it may even be possible to develop reasonable theories allowing predictions of the UHI profile. All we would then need would be the original temperature data (oh; I keep forgetting; they can’t find it…) to allow a properly adjusted (for UHI) temperature series to be developed
Been a G4 since ’75….
The APRS radio is a good idea, however at least some can not do wx and gps at the same time. The Kenwood TM D710 says a gps OR wx station. They plug into the same place.
Kenwood suggests the Davis Instruments Vantage Pro 2 as an acceptable instrument.
Bruce G. Wilkins KE9VZ
Now we may start to get some accuracy –
Then again, how do we know if some of these hams may not be trolls for AGW?
But at least it is a start.
This would just increase coverage of areas that are already covered. How do we get data from the Arctic region, where it’s currently being made up from the comfort of GISS offices thousands of miles away?
I have the Davis Vantage Pro 2. This weather station is very accuate as long as I monitor the calibration. My data is QC’ed by findu.com daily. I check it about once per month to see if my data is calibrated. If I need to calibrate the station, I can easily make the change in the software I have. Findu also provides sitting information. My station is sat properly and is quite accurate. I can’t say the same for other stations around me. As for the OS stations, I had one for about a year. It lost it calibration after about three months. It was also very hard to calibrate and shield from the sun, and any time it rained, the aenonometer would stop reporting. Hey, the station cost $300. My Vantage station is excellent. It was $1200 and well worth it. My findu.com ID is CW8931, so check the data. I live on the SW side of Houston. I know for a fact that UHI is a huge around Houston. My station can be up to 10 degrees cooler than KHOU or KIAH, that’s mostly in the fall and winter after sunny days. I would say on average I’m about 2-3 degree cooler then KHOU and KIAH.
You don’t really need to use APRS and lots of people to gather this data.
Simply do a deal with your local bus company and/or train company and place a data logger with GPS and temperature inputs at some suitable location on a few dozens of vehicles.
With modern trains it’s even easier as they all log air intake temperature anyway.
Now let loose these vehicles to ply their trade into and around the city for a year or so. It’s preferable to use routes from urban to rural and vice-versa.
What you are looking at is not the absolute accuracy, but the relative temperature changes as they move through the day.
The combination of long-term sampling and multiple vehicles will eventually give a nice differential temperature map that can be dissected X ways to get night and day, urban and rural temperature profiles.
I am an U.S. licensee and PC programmer with experience writing APRS software. If Anthony et al. can work out the accuracy issues, I’ll volunteer any required programming to support the effort.
73
Is Morse Code still a requirement for a license? I have already learned and forgotten Morse several times in this iteration.
Code is no longer required for ham radio. There are more than a
dozen digital modes now — and code is only one of them.
APRS is interesting because the transmitters, receivers, data gathering and
graphing software all exists already. In order to get good sampling, all that
is needed is a high-precision thermometer and a communications protocol
on top of the APRS. Currently the APRS display software does a
GPS-to-zipcode translation, looks up the zip code internet, finds the most
local temperature on the internet, and shows that. Sending the real temperature
instead is a small step.
Especially here in OC, sampling by bicycle would provide an interesting
control point. Little vehicle heat and constant slow movement would
likely be more be informative that stop&start.
Sampling units on buses and trains is a good idea. Here in OC we have
some long-circuit bus routes that might show variations in the the
urban micro-climates.
To make a new temperature network of value the data produced must be of the highest, unimpeachable, quality. The last thing we need are more class 3 thru 5 measurement stations.
Set up a system of qualification and licenses similar to Ham Radio, and have annual inspections by a local board of master class members. Then post the inspection results and collected data to a board like surfacestation.org. The goal should not only be to post data, but embarrassingly robust data to shame NOAA into fixing their network.
I’ve got to agree; VHF/2 Meter APRS as currently implemented requires a good over-the-air S/N ratio with no inherent EDAC (error detection and correction) in the protocol … makes for corrupted ‘data’ for all but full-quieting signals, thereby requiring a well-placed repeater and a good 35 Watt mobile transceiver a good outside the car antenna …
Better to go with another’s suggestion with the use of Bluetooth and cell phones; participation by ‘civilians’ (the average Joe) would be a lot higher too.
Fill Disc.: Long time comm guy and licensed ham.
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I’m not a ham, but it sound like a good idea. Not all the data has to be for UHI measurement. The units can be stationary much of the time and some could be stationary all of the time. There are probably over one million hams in the world.
If one percent joined in, we could overcome the great thermometer dying.
makes for corrupted ‘data’ for all but full-quieting signals, thereby requiring a well-placed repeater and a good 35 Watt mobile transceiver a good outside the car antenna
If that were true, the APRS system would essentially be overrun with bad data, which it isn’t. You ought know something about that which you attempt to represent to others. Furthermore, APRS digipeaters (not called repeaters in APRS lingo) are only needed to spread the xmission over a region, not to IGate it to the Net. Finally, even medium to small cities, which would be the minimal targets, tend to have iGates if not digipeaters. The only technical issues that needs to be resolved is temp data accuracy and collection methodology. The APRS issues are easily dealt with.
Obviously somebody who doesn’t know the full value of FEC and base-band modulated signals as used by other services.
It’s pretty easy to ‘claim’ you have satisfactory service when you have no other experience and only worked over near line-of-site paths to a digi-peater strategically located waaaay up a tower … you know not what a properly designed and optimally performing data system can *actually* do.
You take your APRS modulation format (what? 1200 baud AFSK on an FM-modulated carrier?) and I’ll take the data format for a Motorola analog trunked system (GMSK with a raw over-the-air data rate of 3600 baud which includes a FEC using a rate 1/2 convolution code, bit interleaving for picket-fence/multipath resilience and a 10 bit block parity code) and we’ll see who has a more robust payload capability, few errors and greater usable range … Full disclosure: I’ve coded-up and tested the receive-side of such a Motorola-format EDAC scheme …
I stand entirely by my words and claims.
What is GMSK Modulation
From: FUNDAMENTAL UNAVOIDABLE FACT OF PACKET LIFE :
Don’t take MY word for it, do a little reading …
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