I can’t imagine why this project exists. We have thousands of weather stations across the world already. Disentangling the temperature of your pocket from the actual temperature seems like an exercise in futility to me. Even the authors claim they can only get within 2.7 degrees Fahrenheit, so what is the point of having this inaccurate data?
From the American Geophysical Union
Crowdsourcing weather using smartphone batteries
WASHINGTON, DC — Smartphones are a great way to check in on the latest weather predictions, but new research aims to use the batteries in those same smartphones to predict the weather.
A group of smartphone app developers and weather experts discovered a way to use the temperature sensors built into smartphone batteries to crowdsource weather information. These tiny thermometers usually prevent smartphones from dangerously overheating, but the researchers discovered the battery temperatures tell a story about the environment around them.
Crowdsourcing hundreds of thousands of smartphone temperature readings from phones running the popular OpenSignal Android app, the team estimated daily average temperatures for eight major cities around the world. After calibration, the team calculated air temperatures within an average of 1.5 degrees Celsius (2.7 degrees Fahrenheit) of the actual value, which should improve as more users join the system.
While each of the cities already has established weather stations, according to the new method’s creators it could one day make predictions possible at a much finer scale of time and space than is currently feasible. Whereas today, weather reports typically provide one temperature for an entire city and a handful of readings expected throughout a day, the technique could lead to continuously updated weather predictions at a city block resolution.
“The ultimate end is to be able to do things we’ve never been able to do before in meteorology and give those really short-term and localized predictions,” said James Robinson, co-founder of London-based app developer OpenSignal that discovered the method. “In London you can go from bright and sunny to cloudy in just a matter of minutes. We’d hope someone would be able to decide when to leave their office to get the best weather for their lunch break.”
The work was published today in Geophysical Research Letters, a journal of the American Geophysical Union.
Smartphone sensors
Robinson’s OpenSignal app collects information voluntarily sent from users’ phones to build accurate maps of cellphone coverage and Wi-Fi access points. The app boasts about 700,000 active users according to Robinson, about 90 percent of which opt in to providing statistics collected by their phones.
Robinson originally wondered whether smartphones running on newer, 4G networks ran hotter than those running on older networks. When no difference showed up, he looked for other potential uses of the temperature information available on Android-powered devices.
“Just sort of for fun we started looking to see if there was a correlation with anything else,” said Robinson. “We got some London weather data for comparison and found the two sets of temperatures were offset, but they had the same sort of shape.”
While OpenSignal is available to iPhone and iPad users, the temperature readings on those devices are not accessible like on their Android counterparts.
Cellphone thermometers
After finding the correlation between smartphone and air temperatures in London, Robinson and his fellow developers assembled temperature data from other major cities where they had a large number of users. Comparing data from Los Angeles, Paris, Mexico City, Moscow, Rome, San Paulo and Buenos Aires, Argentina, they saw the same link between the two sets of temperatures they saw in London.
“It was amazing how easily the correlation sort of popped out,” said Robinson. “We didn’t do any handpicking of data—it sort of just emerged.”
A smartphone’s environment affects its temperature, according to Robinson. On a sweltering day, a cell phone tucked in a pocket will be hotter than the same cell phone on an icy day. Weather experts helped Robinson develop a way to calculate outdoor temperatures from smartphone battery temperatures, the latter of which are typically hotter.
However, other factors unrelated to the outdoor weather can play a role. A phone outdoors running the latest 3-D game could run at 46 degrees Celsius (115 degrees Fahrenheit) while the same phone idling in an air-conditioned building nearby could be only running at 27 degrees Celsius (80 degrees Fahrenheit).
To avoid fluctuations in temperature unrelated to the real outdoor temperature, Robinson needed large amounts of data. While an individual phone might not provide an accurate representation of the weather, combining the readings from hundreds or thousands of phones together gives a more truthful overall picture. Currently Robinson collects over half a million temperature readings each day from users of his OpenWeather app. He said he plans to make the data freely available to academic researchers.
“There’s the wider promise when logging all this information that there will be something really interesting you can understand,” said Robinson. “The most obvious application is climate and weather tracking.”
Personal weather predictions
Currently weather tracking primarily takes place at weather stations, such as those at airports. However, weather stations provide only one point of reference and are rare outside of densely populated areas, forcing weather forecasters to fill in the gaps when making their predictions, reducing both accuracy and how specific an area they can make predictions for.
While Robinson says his multitude of mobile phones can provide large amounts of data, individual areas still need to be fine-tuned using existing weather stations before the incoming information can be usable for weather prediction.
“The challenge is whether we can take this technique and use it in places where we don’t already have reliable weather information to retune the model,” said Robinson. “That’s something we’re still working on.”
Robinson says some recent smartphones come with built-in sensors specifically built to measure the environment around them such as air temperature, humidity and pressure. To take advantage of these features, Robinson and his fellow developers released WeatherSignal, an app built around mobile weather watching.
As these features become commonplace in the smartphone market, Robinson foresees smartphones becoming an important tool in weather monitoring.
Notes for Journalists
Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of this early view article by clicking on this link: http://onlinelibrary.wiley.com/doi/10.1002/grl.50786/abstract
Could come in handy when dating, you could tell if your date is getting hot and heavy.
I’d bet this has less to do with science as it has to do with Waze.
Or more specifically, Waze getting bought for $1 billion dollars.
Waze = crowdsourced traffic – despite all kinds of alternate traffic data available (Google was paying Inrix for traffic data, presumably not anymore).
The above = crowdsourced weather data.
It won’t be long before they start walking down the temperatures from our 1930s cell phone records.
TerryT says:
August 13, 2013 at 5:30 pm
Could come in handy when dating, you could tell if your date is getting hot and heavy.
>>>>>>>>>>>.
Omigod. Worse than pet rocks. They’ve reinvented the mood ring.
So for teenagers the temperature of the phone would be about right as it is always attached to the side of their heads, but for folks like me it would say the climate was a continuous 98±1F, because it is usually in my front pocket, except for right now when it is completely lost.
Oh! Oh! We are now going to have the UJI or the Urban “Junk” Island effect.
The most ‘accurate’ way to get a temperature reading of a cellphone carrier’s environment would be to use the technology in temporal thermometers. When a call comes in, that technology kicks in and sends a time-sensitive signature of the surrounding temperature as the cellphone leaves its holding environment; is touched by a hand; that then passes the phone through the air; and up to an ear. By looking at and cataloging the values and shapes of many such ‘typical’ ways users handle their cellphones, and rejecting the outliers, it just might be possible to crowd source a temperature trend over the next century. Quick, get a grant!
Michael J. Dunn says:
August 13, 2013 at 12:30 pm
There is no way at all that you can measure the air temperature from a bunch of phones, however many you use. They are in pockets etc, spend most of their time indoors or in cars anyway, and will probably be kept warmer when it is either cold or wet. How can that possibly measure outside air temperature, even relatively?
“In London you can go from bright and sunny to cloudy in just a matter of minutes.”
Yeah, and vice versa.
M. Courtney thinks measurements are representations of reality. Okay. But my pocket is a different reality than the city around me. No amount of data about the one reality will tell you anything about the other. Most cell phones are in someone’s purse or pocket, covered by 1 to 8 layers of fabric and located in a car or building. This “idea” is utterly worthless. Garbage x 1,000,000 = garbage.
CodeTech says: “Wouldn’t it make more sense to build a network to monitor the outdoor thermometers built into most cars?”
The NSA will nix this idea and will refuse to say why.
a Rube Goldberg device looking for something to do. [ H. R. 8/13 at 2:31PM]
Yup! #[:)]
“It isn’t necessarily daft.”
Totally daft. Most folks spend very little time of the day actually outside. Most are at work 8 hours a day and asleep 8 hours a day. If it is cold outside most seek indoors for warmth. If it is hot outside, well look for the A/C. Don’t buy it for a minute.
Justification for monitoring location and data on every phone.
From tmonroe on August 13, 2013 at 1:40 pm:
I love lithium ion batteries. Sure, I’m changing the set in the TV remote every two weeks, but I’m not buying or throwing out any.
You can get a wall charger with 4 batteries for about the battery cost. Last Rayovac set was a plain black charger (#PS132), AA’s and AAA’s charge in pairs, I left them in. I noticed the batteries got rather warm, while a different charger with auto shutoff stayed cool.
After attacking with the “tamperproof screw” driver set, I found a small transformer and two circuits from the secondary. Each was a single diode (not full wave), then the batteries in series, and an LED with a ballast resistor that would stay on whenever the batteries are in.
No microchips, no sophisticated charging controls. Oh, and the manual says the LED’s go on to show charging, and stay on to show the batteries are charged.
Made in China.
It’s nice that lithium-ion batteries are, by design, now being used as heating elements when not being energy reservoirs. It clearly shows overheating Li-ion batteries are not the problem they used to be.
davidmhoffer and M Courtney:
I did not intend to comment in this thread but have been called as arbiter in your discussion.
The scientific value of the app is clearly stated in this thread by Joseph who says at August 13, 2013 at 2:14 pm
http://wattsupwiththat.com/2013/08/13/how-is-the-temperature-of-your-pocket-useful-for-meteorology/#comment-1388868
However, if the purpose of the app is to make money for its vendors then it may fulfill its purpose (i.e. be a financial success) because a claim that the app provides climate data suggests it can be sold to the gullible who support AGW.
Richard
Actually, the way I chose to interpret this paper was that it is a first step in the preparation and analysis of crowd-sourced environmental data. One of the key issues with the study of urban microclimate is a terribly low density of measurement. For example, a city might have one or two meteorological stations and then now and again a few short-term field campaigns but this isn’t enough to tell you about the temperature variation inside the city and inform sub-grid scale modelling. i.e. I don’t feel this is intended to tackle the issue of GLOBAL warming, it’s just a method to potentially capture the range of temperature in an urban environment. This study is a primitive first step exploring the possibility of using smart-device technology to sample, providing a network of interconnected “samplers” that are integrated already into an urban environment. In the future, perhaps phones could measure a suite of things, temperature, heat flux, pollution… Sometimes it pays not to take a piece of research as a literal finished article and consider the possible developments that could be wrought from it.
I can’t see how any useful data could be obtained. As the measurements are of the battery temperature this would have a difference with actual ambiant temperature by some unknown variable x. x would be made up of systemic errors (non-calibration and distance from known calibrated temperature guage) and random; placement, battery age, proximity to other temperature differentials. Therefore error x = p*ba*pr*dt*(systemic error) No matter how many x’s you have as each is an independent variable (time and place are unique events) you will not be able to eliminate the errors or determine any trend from noise (as it will all be noise)
“In London you can go from bright and sunny to cloudy in just a matter of minutes.”
or
“In London you can go from bright and sunny to indoors in a matter of seconds.”
or
“In London you can go from bright and sunny but very cold to a heated building in a matter of seconds.”
or
“In London you can go from bright and sunny and hot to an air-conditioned building in a matter of seconds.”
etc…
Paraphrasing Mae West — “Is that your smartphone batteries’ anomaly increasing or are you happy to see me?”
Now all we need to do is give everyone in Sub-Saharan Africa a mobile phone and we’ve got an even better spread of data.
Do mud huts have a plug point for charging your phone?…..
If the phone is down inside my pants the temperature will always be smokin’ !
Although my wife might disagree…
Further to my car thermometer idea, any car with GPS and an external thermometer could be a mobile temperature station. All someone needs to do is drop a $30 Made-in-China RF module on the CanBus somewhere and, a few minutes after starting (to give you time to get out of a parkade or garage and allow for heat-soak dissipation) it would be sending a temperature reading and location at set intervals. These things are usually quite accurate and placed where they’re not very much affected by the radiator or A/C condensor.
But, of course, that assumes that “Climate Scientists” actually want to know the real temperature. I’ve seen very little to make me think they do.
The cell-phone idea is pure marketing hype to sell an app.
This is useless for temperature trends.
However, I predict this will be a tree-ring-quality proxy for:
-teenager cellphone usage trends;
-battery charging frequency;
-latitude of where the cellphone is used;
–
Thousands temperature measurements all over major cities, though unprecise, might be very useful for studying UHI.
UNTIL some big ‘event’ happens and every-one like-utilizes their iPhone/Smartphone on that occasion and/or for the week following, or new model changes/new model introductions introduce a skew (shift) in data requiring ‘adjustments’ to be made … point being not-so-random factors will be present over longer periods of time encompassing several model-lifetimes … then there is the aspect of where the temp sensor IC placed within the device as battery position in device design caries from model to model, and even composition changes in battery technology yielding different temp profiles during charge/discharge and device-use.
.