Turning airliners into flying weather stations

From Scripps Institute New Airborne GPS Technology for Weather Conditions Takes Flight

First-time demonstration led by Scripps Institution of Oceanography captures key meteorological data from aircraft, along with the potential to improve hurricane forecasting

GISMOS system

A new GPS system aboard airplanes tracks key atmospheric conditions.

GPS technology has broadly advanced science and society’s ability to pinpoint precise information, from driving directions to tracking ground motions during earthquakes. A new technique led by a researcher at Scripps Institution of Oceanography at UC San Diego stands to improve weather models and hurricane forecasting by detecting precise conditions in the atmosphere through a new GPS system aboard airplanes.

The first demonstration of the technique, detailed in the journal Geophysical Research Letters (GRL), is pushing the project’s leaders toward a goal of broadly implementing the technology in the near future on commercial aircraft.

Current  measurement systems that use GPS satellite signals as a source to probe the atmosphere rely on GPS receivers that are fixed to ground and can’t measure over the ocean, or they rely on GPS receivers that are also on satellites that are expensive to launch and only occasionally measure in regions near storms. The new system, led by Scripps Institution of Oceanography geophysicist Jennifer Haase and her colleagues, captures detailed meteorological readings at different elevations at targeted areas of interest, such as over the Atlantic Ocean in regions where hurricanes might develop.

“This field campaign demonstrated the potential for creating an entirely new operational atmospheric observing system for precise moisture profiling from commercial aircraft,” said Haase, an associate researcher with the Cecil H. and Ida M. Green Institute of Physics and Planetary Physics (IGPP) at Scripps. “Having dense, detailed information about the vertical moisture distribution close to the storms is an important advancement, so if you put this information into a weather model it will actually have an impact and improve the forecast.”

“These are exciting results, especially given the complications involved in working from an airplane,” says Eric DeWeaver, program director in the National Science Foundation’s (NSF) Division of Atmospheric and Geospace Sciences, which funded the research. “Satellite-based measurements are now regularly used for weather forecasting and have a big impact, but airplanes can go beyond satellites in making observations that are targeted right where you want them.”

The GRL paper details a 2010 flight campaign aboard NSF aircraft and subsequent data analysis that demonstrated for the first time that atmospheric information could be captured by an airborne GPS device. The instrumentation, which the scientists labeled “GISMOS” (GNSS [Global Navigation Satellite System] Instrument System for Multistatic and Occultation Sensing), increased the number of atmospheric profiles for studying the evolution of tropical storms by more than 50 percent.

“We’re looking at how moisture evolves so when we see tropical waves moving across the Atlantic, we can learn more about which one is going to turn into a hurricane,” said Haase. “So being able to look at what happens in these events at the early stages will give us a lot longer lead time for hurricane warnings.”

“This is another case where the effective use of GPS has the potential to improve the forecast and therefore save lives,” said Richard Anthes, president emeritus of the University Corporation for Atmospheric Research, which currently runs the satellite based GPS measurements system called COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate).

While the current GISMOS design occupies a refrigerator’s worth of space, Haase and her colleagues are working to miniaturize the technology to shoe box size. From there, the system can more feasibly fit onto commercial aircraft, with hundreds of daily flights and a potential flood of new atmospheric data to greatly improve hurricane forecasting and weather models.

The technology also could improve interpretation of long-term climate models by advancing scientists’ understanding of factors such as the moisture conditions that are favorable for hurricane development.

Paytsar Muradyan, who recently received a Ph.D. from Purdue University in atmospheric sciences, started working with Haase in 2007 as a graduate student during the formative stages of GISMOS’s design and development. She eventually flew with the group in the 2010 campaign and took away a wealth of experience from the demands of the project.

“It was a lot of responsibility but certainly rewarding to work with a group of world-known scientists in an interdisciplinary project,” said Muradyan.

In addition to Haase and Muradyan, coauthors of the project include students Brian Murphy and Kuo-Nung Wang, and Professor James Garrison of Purdue University; F. Felipe Nievinski of Universidade Estadual Paulista, Presidente Prudente (Brazil); and Professor Kristine Larson of the University of Colorado, Boulder.

Funding for the project was provided by NSF, NASA, the Ross Fellowship, the Schlumberger Faculty for the Future Fellowship, the Capes/Fulbright Graduate Student Fellowship, and a NASA Earth System Science Research Fellowship.

About these ads

42 thoughts on “Turning airliners into flying weather stations

  1. Not sure that this is news. Qantas and other Australian airline aircraft have had a weather reporting system onboard for years, used in conjunction with radiosonde data to plot upper air charts. The main issue with present technology is making humidity sensors robust enough to withstand the rigors of aircraft usage, especially vibration, so the main data gathered is temperature and wind speed/direction.

  2. Sorry, a bit O/T:

    It is a serious pity (even after 9/11) that persons on board a civilian airliner are able to disengage the flight identification transponders, and the ACARS system. How much would it cost, seriously, to install a proper GPS locator for all commercial aircraft, which could NOT be disabled by a person or persons unknown? Minuscule, compared to the value of the airliner, let alone its pax!

    The lawyers for the families will have a field-day with MH-370.

  3. The technology also could improve interpretation of long-term climate models“. I doubt it. If the climate models are wrong, no amount of interpretation of them will help. I suspect they meant that interpretation of the data from the technology could help improve the models. I doubt that, too, until some other major changes have been made to the models.

  4. One thought I had a few years ago during a public/private weather agency included replacing some weather balloon observations with autonomous gliders launched from FedEx’s air fleet. They would be released near FedEx sorting facilities and glide (with GPS guidance) to a rooftop landing. They be picked up, data sent to the weather guys, and repacked for a trip back to the airport with the next truck and installed on the next plane out.

    I bet this could provide much more data than the weather balloon program does for much less money. Weather ballon data reports data higher than flight levels, we could either live without it or work on providing a VAP – Vertical Assistance Package.

  5. This abstract is misleading. It does not describe a system which reports meteorological conditions using GPS positions. That does exist; see here for one such system:

    http://cliffmass.blogspot.com/2013/09/critical-aircraft-weather-data-unused.html

    The key phrase in this abstract is “systems that use GPS satellite signals as a source to probe the atmosphere”. The atmospheric conditions that affect the accuracy of a GPS signal, such as moisture in the signal path, could be studied by examining the timing anomalies of the signals over the paths they travel.

  6. On the topic of new data, climate.data.gov has launched.

    “Here you can find data related to climate change that can help inform and prepare America’s communities, businesses, and citizens. Initially, in this pilot phase, you can find data and resources related to coastal flooding, sea level rise, and their impacts. Over time, you will be able to find additional data and tools relevant to other important climate-related impacts, including risks to human health, the food supply, and energy infrastructure. Please share your feedback.”

  7. Until it gets turned off.

    Incidentally, SPDRDR, there are valid reasons why things like automatic comms might be turned off: in the event that they are giving misleading positional information etc.

  8. I realise this is terribly prosaic, but bright idea = more kit = longer turn-round time + increased weight = higher fuel consumption = extra cost to the carrier. Who pays?

  9. And after they manage to get the device down to shoebox size, they’ll have to sell the idea to the commercial airlines. What benefit would airlines get from installing it? If there’s none, the device would just be dead weight.

    • As I mentioned in an earlier post, Qantas have had weather data recording and transmitting devices fitted for quite some time.Qantas was and remains supportive, on the simple basis that the data provides better data for flight forecasts.

      • Qantas (no “U”) has made a loss due to pure local reasons- the other carriers allowed to operate here have foreign capital to work with. Qantas is barred from substantial foreign investment. Qantas remains one of the safest airlines to fly with. Hardly a “basket-case”.

  10. OMG the contrail nutters will go ape over this. Just one more piece of “weather war technology” or some such bulldust. I would go a step further and use some surplus UAV’s (Post Afghanistan of course) . Look at it this way. No pilot on-board, can stay in the air for hours without any supervision, can fly above normal air traffic heights and can be tasked away from their assigned area if needed. Just need the right packages on-board, already has the military standard GPS packages installed, could be used to Cyclone/Typhoon/Hurricane/Tornado chase or could be used in a weather emergency to bring back real time weather information.

  11. Look what happened to the thermometer data we had. As soon as we start getting ‘adjustments’ to this aircraft data because it is not what is expected, we’re right back to square one.

    More data in the wrong hands is more wrong data.

  12. Aircraft fly at a pressure height based on 1013.2mb which enables the correct flight separation between aircraft. GPS can give real altitude (sometimes) so the difference between the two will give an indication of surface air pressure at the aircraft’s position, known from the GPS. Other bits of useful information like local lapse rate, surface temperature etc are more of a problem.

  13. RMF says:
    March 18, 2014 at 10:00 pm

    > On the topic of new data, climate.data.gov has launched.

    And crashed? I get a long delay and then:

    Error

    Data.gov is temporarily unavailable. We apologize for this inconvenience and assure you that work is underway to correct this problem. Please check back in 15 minutes and thank you for using Data.gov.

  14. [Oops – didn’t save the edit buffer ignore the above comment.]

    RMF says:
    March 18, 2014 at 10:00 pm

    > On the topic of new data, climate.data.gov has launched.

    And crashed? I get a long delay and then:

    Error

    Data.gov is temporarily unavailable. We apologize for this inconvenience and assure you that work is underway to correct this problem. Please check back in 15 minutes and thank you for using Data.gov.

    BTW, it’s not a .gov site:

    $ host climate.data.gov
    climate.data.gov is an alias for http://www.data.gov.edgekey.net.
    http://www.data.gov.edgekey.net is an alias for e4605.dscb.akamaiedge.net.
    e4605.dscb.akamaiedge.net has address 23.48.30.173
    e4605.dscb.akamaiedge.net has IPv6 address 2001:559:11:197::11fd
    e4605.dscb.akamaiedge.net has IPv6 address 2001:559:11:189::11fd
    e4605.dscb.akamaiedge.net has IPv6 address 2001:559:11:190::11fd

  15. It is a serious pity (even after 9/11) that persons on board a civilian airliner are able to disengage the flight identification transponders, and the ACARS system. How much would it cost, seriously, to install a proper GPS locator for all commercial aircraft, which could NOT be disabled by a person or persons unknown? Minuscule, compared to the value of the airliner, let alone its pax!
    The problem isn’t installing a proper GPS locator, it is building an infrastructure to receive these position reports in sparsely populated areas, such as the area in where Air France 447 was lost. The only practical means is to launch a new series of low orbit satellites that are equipped to receive and relay the volume of data that would be generated by the thousands of aircraft airborne worldwide at any given time.

    There are thoughts of putting “cloud-based black boxes” on commercial aircraft, which would essentially be your idea. Perhaps MH370 will be the catalyst to make this a reality, and a local weather reporting system could be incorporated at little additional cost.

  16. ‘“This is another case where the effective use of GPS has the potential to improve the forecast and therefore save lives,” said Richard Anthes’

    Grant fishing BS.

    “with hundreds of daily flights and a potential flood of new atmospheric data to greatly improve hurricane forecasting and weather models.”

    More grant fishing BS.

    Also note that these people are working to produce more data. No one is working on doing anything with the data. This is “build it, and they will come” BS.

    A nation $17,000,000,000,000 in debt, and it’s got money for this. Our decadence will be our death.

  17. I haven’t looked at the actual report – do they address the issue that the airspace covered by commercial airliners typically follows well-traveled routes across the Atlantic, which would give an abundance of samples in areas that may have little bearing on predicting the formation and course of tropical storms?

    Or perhaps obtaining a large quantity of observations is not the goal, inasmuch as any observations whatsoever over the area of interest would provide data where otherwise there is none.

    BTW, as noted above, a lot of the commenters seem not have grasped the concept of the GPS satellite signals themselves being used to probe atmospheric conditions, as opposed to merely being used to give the location of readings taken by more conventional weather measurements.

  18. Ric Werme–it is a .gov site.

    Here’s what the about page says about climate.data.gov

    “Data.gov is the home of the US government’s open data.

    You can find Federal, state and local data, tools, and resources to conduct research, build apps, design data visualizations, and more.

    The Data.gov team works at the U.S. General Services Administration, but the site itself is open source, and we’d love your help making it even better.”

    There’s a story about it today in the NYT and other places.
    Check it out.

    “As part of its effort to make the public see global warming as a tangible, immediate and urgent problem, the White House on Wednesday will inaugurate a website aimed at turning scientific data about projected droughts and wildfires and the rise in sea levels into eye-catching digital presentations that can be mapped using an app.”

    http://www.nytimes.com/2014/03/20/us/politics/white-house-to-introduce-climate-data-website.html

  19. Regarding GPS locators: General aviation already has the gear and infrastructure, using the Iridium satellite-phone network, generally costing under $200/month to track aircraft position at one-minute intervals. For example http://us.spidertracks.com/

    I’m sure commercial airliners could install something similar.

  20. on the surface, I think the basic idea is valid as more data is always more better….until someone ‘adjusts it’.

    A weakness is the falacy that it really adds that much over what we already have. Sure it would give us tons of data from all the flights, but in reality most of those follow exactly the same course. More redundant data is not really more useful data.

  21. Why not do an ARGO project for the atmosphere? In fact, why not extend ARGO above sea level so that each buoy performs a sounding while on the surface? Why not install a network of fully automated sounding sites all over the planet at randomly determined fixed locations, and actually measure atmospheric conditions on a gradually improving grid that isn’t shaped by the accident of where humans live in large numbers and corrupt local measurements with UHI? Why not install automated sounding devices all over the world’s deserts, where one in principle might be able to directly measure the CO_2-connected GHE change over a decade (at least, if it is as large as it is purported to be, it should be easy to measure there)?

    After all, if this were done with random site selection, it would by construction not require a UHI correction at all (and indeed, would give us the data needed to increasingly precisely determine the UHI effect and the mean contribution of LOCAL warming to current estimates of GLOBAL warming).

    ARGO itself is flawed because far too many of the buoys are not moored and are not located at randomly selected sites. It’s like nobody has ever heard of Monte Carlo and the importance of random sampling when constructing unbiased estimates, just as people have apparently never heard of rescalable icosahedral tessellations of the sphere and the problems with kridging and extrema on a sparse grid, or using a kridge or any other interpolating polynomial to do a quadrature as a step towards evaluating an estimate of the mean, especially on a coarse grained spherical polar coordinate decomposition of a spherical surface with its polar singularities.

    rgb

  22. My only concern is that trans-oceanic tracks are typically moved away from big weather events if at all possible, so that you may not get the information that is of most interest when you could really use it. Airliners are not hurricane hunters; they are hurricane avoiders; the same goes for avoiding storms in the ITCZ when flying N-S or S-N.

  23. To further elaborate, moving the tracks to avoid weather could mean you end up with favorable selection of samples, because, if at all possible, the aircraft tracks will be located in fair winds over following seas, instead of flying into the teeth of a storm. Thus over time, all the samples in a given are will be more likely than not to be representative only of good weather in the area, but not provide the overall picture, including stormy weather.

  24. It’s like nobody has ever heard of . . . rescalable icosahedral tessellations of the sphere and the problems with kridging and extrema on a sparse grid, or using a kridge or any other interpolating polynomial to do a quadrature as a step towards evaluating an estimate of the mean, especially on a coarse grained spherical polar coordinate decomposition of a spherical surface with its polar singularities.

    Ya think?

  25. Katherine says: And after they manage to get the device down to shoebox size, they’ll have to sell the idea to the commercial airlines. What benefit would airlines get from installing it? If there’s none, the device would just be dead weight.

    A system regularly transmitting GPS locations would also provide yet another way of tracking of Malaysian Airlines planes. It would be particularly useful if mounted in a place where the pilots can’t turn it off

  26. The article is here:

    http://onlinelibrary.wiley.com/doi/10.1002/2013GL058681/full

    It discusses how doppler readings are used to extract the refractive index of the air along the ray path. This is the same technique that has been used to measure the atmospheres of other planets as spacecraft fly behind them, just applied at Earth, and with a dozen satellites overhead. a measurement is obtained each time a sat rises and sets (1 to 2 per hour), getting a humidity measurement along each line of sight.

    GPS radio occultation uses radio signals to sense the atmosphere as a transmitting GPS satellite sets behind or rises above the horizon relative to a moving receiver (Figure 1). The radio waves undergo refractive bending and a Doppler shift due to variations of refractive index within the atmosphere primarily in the vertical direction. The refractive index in the neutral atmosphere depends on the pressure (hPa), P, temperature (K), T, and water vapor partial pressure (hPa), e,

    [equation here]

    [Rüeger, 2002]. Thus, information on the structure of the atmosphere can be retrieved from precise measurements of the amplitude and Doppler shift of the radio waves.

    That the signal is used for navigation is immaterial to the science instrument, it’s the carrier wave that’s being measured. To get the airlines to carrier the science packages is quite simple- pay them for the privilege. Encourage the airlines to boast of how they are helping further scientific research and the price should go down some. :)

  27. Ric – Akamai is a site which maximizes a response speed on the Net by caching the original web page in a server near your location. .gov sites are free to use akamai services.

  28. The paper seems to indicate that GPS signals themselves are used to measure meteorological data. Not impossible in itself; let’s say the GPS device gets signal from 7 satellites in different directions. The problem is that each signal is distorted by – let’s say we are interested in water vapor – an overall water vapor along this signal’s path. To deduce a vertical distribution of water vapor from these 7 signals seems next to impossible to me. It would be nice to see error margins.

  29. Ya think?

    Well, OK, maybe that was a bit over the top, but they should be aware of all of those things:

    http://en.wikipedia.org/wiki/Geodesic_grid

    Note scaling in figures — note also that this tiling has been in use since at least 1968 for geophysical problems. Yet it is my belief that basically all of the GCMs use lat-long spherical polar tiling with completely asymmetric tile shapes and areas. I quote from the article (referring to the universally used lat-long grid):

    “However, such a pattern does not conform to many of the main criteria for a statistically valid discrete global grid,[2] primarily that the cells’ area and shape are not generally similar; this is especially noticeable as the cells are developed towards the poles.”

    As you say, “Ya think?”

    Then there is Kriging:

    http://en.wikipedia.org/wiki/Kriging

    Note well two things from this article. First of all, note the enormous uncertainty of the interpolation in one dimension with a moderately sparse grid. This uncertainty strictly depends on assumptions made about the underlying process being fit — again I quote: “Under suitable assumptions on the priors, kriging gives the best linear unbiased prediction of the intermediate values.” That’s sort of like saying “if the process being interpolated is nonlinear, or if the prior assumptions one makes are unsuitable, kriging will not give you the best unbiased prediction of the intermediate values”. Second, note from the figure itself note that the specific place where the interpolation is quite different from other e.g. spline interpolations is in interpolated segments where an extremum (probably) occurs. Here’s where those prior assumptions come into play — cubic splines are well-known to be very good for certain classes of problem, and still other interpolating polynomials can be good for still other classes of problem.

    It seems reasonably likely that kriging underestimates extrema, possibly systematically, and it is virtually certain that it leads to very large errors across the interpolated regions. One is then left with nothing but a “fond hope” that those errors are symmetric and on average cancel, as opposed to systematic so that they don’t.

    Finally, there is a well-known connection between interpolating functions and quadrature (numerical integration):

    http://en.wikipedia.org/wiki/Numerical_integration#Quadrature_rules_based_on_interpolating_functions

    The idea is that one numerically interpolates a set of data points with some smooth function (e.g. piecewise polynomial) according to some criterion, and then integrate the interpolating function one constructs to estimate the integral over some sampled domain. Note well that error estimation is serious business and is based on all sorts of assumptions that any numerical/computational scientist knows can easily be defeated by nothing more than bad luck for any given non-adaptive grid. This is why using adaptive methods are absolutely key.

    Note also the comments in the article about multidimensional integrals and the curse of dimensionality. Note the solutions — Monte Carlo (which I mention above) or some very sophisticated methods one can implement for sparse, non-uniform grids on hypersurfaces or in hypervolumes that may or may not be flat. Again, errors are enormously difficult to control for sparse, non-uniform, non-random grids on curved surfaces, and most oversimplified forms of linear interpolation quadrature are going to really suck.

    Since estimating global surface temperature is precisely taking an irregular, sparse, non-uniform sampling of points locally averaged in 5×5 degree lat-long surface cells, kriging to interpolate, integrating the interpolation over the area, and then dividing out the total “spherical” area, all of these remarks are entirely apropos, and IMO are serious criticisms of the GCMs right out of the box(es).

    I could, of course, be wrong — maybe there are GCMs built on rescalable icosahedral grids — but none of the ones I’ve looked at so far were, and a lot of them (if not all of them) seem to share “DNA” at this level — use common lat-long input data, use a similar gridding, etc.

    rgb

  30. Oops, didn’t close the blockquote properly. The equation shows that the refractive index is mostly sensitive to pressure over temperature, less than 10% as much to humidity over temp, and also to humidity over temp^2. I’m not sure how they back out “e” from the “n” measurement with P & T unknown.

  31. spdrdr says:March 18, 2014 at 8:56 pm “How much would it cost … to install a proper GPS locator for all commercial aircraft, which could NOT be disabled by a person or persons unknown? ”

    Apparently not much considering that trucking companies and DPW’s already install them in semi’s and snow plows. (However… I believe those rely on ground cell service to rely the GPS info to the home office so airplanes would have to use something like Airfone over the USA unless we start allowing cell phones from airplanes.)

    But your point brings up an interesting dovetail to GPS weather reporting from airplanes in that it could easily be incorporated into long-haul semi tractor-trailer trucks right now. There are a lot more trucks, distributed over a lot more area than there are airliners resulting in finer resolution of barometric pressure and temperature, (well.. temperature on asphalt but consistently so for 99%).

    Plus, with so many trucks going in and out of cities every day, imagine how it could refine the issue of UHI magnitude?

  32. Doug Jones gave the URL for the article. If you read that, or if you glance at the illustration at the top of this post, you will see that the GPS satellites used by this method are the ones that are extremely low to the horizon. These satellites are not very useful in navigation because the path of the signals passes through so much of the atmosphere, causing timing errors. An airliner flying at altitude, above the weather, has plenty of GPS satellites with clean signals to establish a position. The border-line GPS satellites near the horizon can then be analyzed and their errors turned into information about the atmosphere along that signal path which grazes the earth, far from the actual position of the plane. Think of it as a kind of over the horizon “radar”.

Comments are closed.