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Science

Spire Plans To Use Tiny Satellites For More Accurate Weather Forecasts 24

Zothecula writes Weather forecasting is a notoriously inexact science. According to San Francisco-based tech startup Spire, this is partially because there are currently less than 20 satellites responsible for gathering all of the world's weather data – what's more, some of the older ones are using outdated technology. Spire's solution? Establish a linked network of over 100 shoebox-sized CubeSats, that will use GPS technology to gather 100 times the amount of weather data than is currently possible. The first 20 of those satellites are scheduled to launch later this year.
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Spire Plans To Use Tiny Satellites For More Accurate Weather Forecasts

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  • by idontgno ( 624372 ) on Thursday January 29, 2015 @06:20PM (#48935737) Journal

    The last I looked, the state of remote-sensing algorithms for limb profiling (i.e., looking through the layer of the Earth's atmosphere over the limb of the planet from your orbital position) is something between bad and "are you kidding?".

    I wonder what kind of secret sauce these Young Turks have that NASA and NOAA doesn't?

    • by ShanghaiBill ( 739463 ) on Thursday January 29, 2015 @06:55PM (#48935965)

      The last I looked, the state of remote-sensing algorithms for limb profiling is something between bad and "are you kidding?".

      But they are not doing much "remote sensing". All they are doing is recording when a GPS signal is received. That's it. That shouldn't be too hard. The delay between when the GPS should have been received, and was actually received, will tell them the index of refraction of the atmospheric cord it passed through, and from that, a ground computer can calculate the humidity, temperature, and pressure.

      • The last I looked, the state of remote-sensing algorithms for limb profiling is something between bad and "are you kidding?".

        But they are not doing much "remote sensing". All they are doing is recording when a GPS signal is received. That's it. That shouldn't be too hard. The delay between when the GPS should have been received, and was actually received, will tell them the index of refraction of the atmospheric cord it passed through, and from that, a ground computer can calculate the humidity, temperature

    • by fermion ( 181285 )
      The first question that popped into my mind was did they have a new model that would take data from 100 satellites and produce a more accurate forecast. I don't think that satellites alone are not going to create a more accurate forecast. This reminds me when I was talking to a teacher back in the 80's. He mentioned that at one point it was believed that if we could create a dense enough network of satellites and sensors, we could forecast the weather with great accuracy and for arbitrarily long periods.
    • by Anonymous Coward

      http://www.spire.com/weather/ is very vague on exactly what they're doing (other than tracking ships at sea and providing a "data link to the cloud")
      GPS occultation using multiple frequencies is a pretty good observational technique. The GPS RO data provides sufficient information to be about the 3rd best source of input to various weather models (after things like ground observations and balloon radiosondes, etc.). Surface winds from satellite scatterometry over the ocean are also useful. One advantage is

  • A sense of scale (Score:4, Insightful)

    by RightwingNutjob ( 1302813 ) on Thursday January 29, 2015 @06:43PM (#48935889)
    is missing in this notion. Meaningful Earth observation from space is done with cameras that take up more physical space than a cubesat. Yeah, you can squeeze several high definition cameras into a cubesat, but the moment you realize that you need something other than visible band, temperture control on the ccds, and the power-aperture to beam that stuff down to earth in a meaningful timeframe, you've built 1500lb worth of overhead around your tiny little cubesat and you're back in GOES and NPP land.
    • by mspohr ( 589790 ) on Thursday January 29, 2015 @06:56PM (#48935979)

      OMG! Quick somebody tell these people that the experts here at /. have decided that they are making a big mistake. I'm sure they will be grateful for all of the expert opinions of our hive mind since it will save them from making a BIG MISTAKE.
      (OTOH, you could RTFA.)

    • Meaningful Earth observation from space is done with cameras that take up more physical space than a cubesat.

      They don't use cameras. They use GPS antennas, as stated in the summary, and explained in the article.

      • OK, my bad. Somebody who's an RF type: Remind me again if the two GPS bands (civil and military) are chosen for their immunity to or responsivity to atmospheric parameters.
        • They are not. The combination of L1 and L2 allows for estimation of the ionospheric delay since the delay is proportional to frequency (difference between L1 and L2). It's all moot now anyway with the availability of reference stations to obtain a correction.
          • Correct, and the ionosphere is not where the weather all is.
            • Seems what they are trying to do is measure the propogation as tangent to the earth as possible; i.e. get a really long propogation through the atmosphere. That would allow them measurements nearer the surface. Now if you did that from several directions, it may be sort of a CT scan, and you can isolate regions instead of the whoe path.
      • For the purposes of environmental remote sensing, there's no difference between cameras and antennas (radiometers); they just image different parts of the EM spectrum. We've had microwave "cameras" on climate and weather satellites since 1972 [nsidc.org]

    • Somebody is certainly missing a sense of scale.

      Traditional Earth observation is done using a small number of satellites at a large distance, traditionally in geostationary orbit (35,786 km away). Using a large number of satellites in low orbit (300 km away), you can use low-power transmitters and commodity cameras. Sure, without cooling, you lose the thermal IR range, but in return you gain a great deal of resolution in the other bands.

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