[HN Gopher] Smartphones can detect solar storms
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       Smartphones can detect solar storms
        
       Author : quantum_fan
       Score  : 19 points
       Date   : 2021-04-18 19:44 UTC (3 hours ago)
        
 (HTM) web link (academictimes.com)
 (TXT) w3m dump (academictimes.com)
        
       | mulmen wrote:
       | Isn't that why solar storms are problematic?
       | 
       | I only skimmed but I didn't see any suggestion of leveraging this
       | capability for any benefit. Is there some advantage to making an
       | array of solar storm detectors from cell phones instead of pre-
       | existing and more capable specialized equipment?
        
         | cryptoz wrote:
         | I haven't studied the data that comes from crowdsourced phone
         | magnetometers yet, but I expect it would follow some properties
         | of other data I've studied, which is
         | 
         | - There are vastly more of these sensors and they are located
         | in places where specialized equipment is not
         | 
         | - The data quality per sensor is very low. You typically need a
         | lot of sensors in a nearby geography in order to get any kind
         | of real data out of it
         | 
         | - Often those geographies where you have lots of smartphones
         | aren't covered by the specialized equipment, so you get new
         | data that you otherwise didn't have
         | 
         | What I don't know is how valuable that extra coverage is or how
         | valuable solar storm data is in the first place.
        
       | cryptoz wrote:
       | I'm working on using smartphone sensors to detect anything they
       | can relating to weather, including space weather - magnetic
       | storms. I've been fascinated with crowdsourcing mobile sensor
       | data for like 10 years now and it's only going to get more
       | interesting: air quality sensors should be making their way to
       | phones soon, others as well.
       | 
       | My open source library with limited sensor features is here:
       | https://github.com/JacobSheehy/AllClearSensorLibrary for Android
       | 'background' access to sensors (using foreground library). I
       | don't think that I've got magnetic data there yet but it's mostly
       | a matter of adding another field.
       | 
       | I've got this running live in an Android app if you want to check
       | it out:
       | https://play.google.com/store/apps/details?id=com.allclearwe...
       | (US-only for now, sorry about that, international weather data is
       | pricey)
       | 
       | I typically track hurricanes with obvious low-pressure curves but
       | there's a lot more that can be done.
       | 
       | Crowdsourcing sensor data from phones:
       | 
       | Accelerometers can detect earthquakes, Microphones can detect
       | noise pollution, Magnetometers can detect solar activity,
       | Barometers can detect weather changes
       | 
       | Most phones have those sensors now, and I'm looking out for UV
       | sensors, air quality sensors, and more. The applications of
       | crowdsourcing sensor data are immense and constantly improving as
       | new sensors get added.
       | 
       | --
       | 
       | The main issues honestly are privacy and noise filtering.
       | Ensemble kalman filters running on device can reduce noise
       | dramatically, and you can use anonymizing features like
       | geographic bounding boxes (where sensors can go in and out and
       | only their bounding box is used as location data)
        
         | mulmen wrote:
         | I can see benefits for local phenomenon like air quality and
         | even temperature. But what's the advantage for using cell phone
         | arrays for cosmic scale events like solar storms? Are the
         | effects of solar storms that different over small geographic
         | areas?
        
           | cryptoz wrote:
           | I don't know, but there's only one way to find out!
           | 
           | Lots of people told me that there was no use at all in
           | measuring air pressure on scales smaller than the US already
           | does with official measurements. But years later, there are
           | multiple papers published and I think IBM now uses their
           | mobile apps to crowdsource barometer data as it improves
           | their weather forecasts.
           | 
           | I'm sure there will be naysayers who even say crowdsourcing
           | magnetometer data is useless, but I don't really care or
           | think they're right.
           | 
           | AFAIK there isn't a large-scale effort yet to study
           | crowdsourced magnetometer data, so we really just don't know
           | yet.
           | 
           | > Are the effects of solar storms that different over small
           | geographic areas?
           | 
           | I don't know but now I'm extremely curious how small the
           | measurable variations are in solar storm effects on Earth.
           | And amazingly, there are _billions_ of deployed sensors all
           | around Earth right now that are simply not contributing to a
           | central network. A simple code library is all that 's needed
           | to know this answer, which to me, is amazing, and a reason
           | enough to try it out.
        
             | mulmen wrote:
             | Yeah after considering this for the last few minutes it
             | makes more sense as just capturing all available sensor
             | data in advance of any specific question.
             | 
             | I'm not sure that solar storm data specifically is useful,
             | maybe interesting. But widespread magnetometer data could
             | have all kinds of unexpected applications.
             | 
             | Detecting solar storms with such an array just seems like a
             | proof of concept.
        
           | wiml wrote:
           | The article headline has been simplified a bit[1]; the storms
           | in question are _geomagnetic_ storms[2]. Geomagnetic storms
           | are perturbations of Earth 's magnetic field by changes in
           | the solar wind (i.e. solar storms).
           | 
           | Having a high-spatial-resolution record of the way the
           | Earth's field changes when interacting with the plasma
           | presumably yields extra insights into how space weather
           | behaves.
           | 
           | [1] The paper: https://doi.org/10.1029/2020SW002669 [2]
           | https://www.swpc.noaa.gov/phenomena/geomagnetic-storms
        
         | diegoperini wrote:
         | I'm okay with giving up my privacy to produce public domain
         | data for science.
        
       | peter303 wrote:
       | They are already used as earthquake detectors. Each one is not as
       | sensitive as a professional seismograph. But thousands of times
       | as many make up for that.
       | 
       | https://blog.google/products/android/earthquake-detection-an...
        
       | tediousdemise wrote:
       | Smartphones are well-equipped these days with a variety of EMF
       | sensors, such as magnetometers.
       | 
       | Makes sense that they'd be good at measuring a powerful magnetic
       | event such as a solar storm.
        
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       (page generated 2021-04-18 23:00 UTC)