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.
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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