Thursday, March 13, 2014

The Search for Flight MH370: Nighttime Satellite Imagery

Still no sign of Flight MH370.  

It's a bracing reminder that the 21st century information-and-technology blanket we've wrapped ourselves in still has a few gaping holes.  High-resolution satellite imagery isn't yet continuous and ubiquitous - not even close.  We're still too often in response mode when something like this occurs, scrambling to deploy the information-gathering tools long after the event occurred and the evidence has faded. If somebody didn't have the awesome foresight to program an imaging satellite, days in advance, so it was ready to snap that critical picture in exactly the right place at exactly the right time, that image never comes into existence. 

But we do have some pretty cool tools nonetheless.  Thanks to the helpful suggestion of a SkyTruth fan (let us know if you don't mind us sharing your name!), we've been looking at the "Nightfire" nightly fire-detection product coming from data collected by the VIIRS instrument on the Suomi-NPP satellite operated by NOAA. That's a lot of capital letters, but you've seen this stuff before if you've been following our blog. These data indicate sources of combustion, and measure the temperature of those fires.  Our assumption is, if the flight went down shortly after air traffic control's last contact at 17:30 GMT on Friday, March 7, we might see an isolated fire from that wreck site for a short period of time.  Maybe one or two days if it crashed over land; less than a day if it hit the water (and didn't immediately sink).  So we looked for short-term, isolated fire-detections that were in remote areas over land, or on the water, within 20 miles of the expected flight path and the western deviation implied by some inconclusive Malaysian military radar data.

Some caveats and disclaimers: 1) Our work with the VIIRS data is by no means exhaustive or comprehensive. So feel free to take a crack at it yourself.  2)  The VIIRS Nightfire product is still experimental, and fires can be obscured by clouds and go undetected. And this is a pretty cloudy part of the world.  3)  There are lots of fires in this area: gas flaring from the many offshore oil platforms in the Gulf of Thailand, intentional fires set to clear land for farming, and wildfires.  

Anyway, we've found a few interesting things during our cursory look at the Nightfire detections. Please share this with anyone who might be in a position to actually use this information.

Overview showing all Nightfire detections on March 8, 2014. Bold orange line shows our approximation of the expected flight path from Kuala Lumpur to Beijing.  Bold red line shows our approximation of the deviation from that flight path that was suggested by eyewitness reports of a jet flying low over Kota Bharu, and Malaysian military radar contact of an unidentified aircraft near Pulau Perak Island. Other points of interest marked and explained in a previous blog post





Gulf of Thailand -- we only found one combustion source we can't confidently explain, although it's in the general vicinity of offshore oil platforms that are flaring gas on a regular basis, and Landsat-8 imagery indicates there may be a platform at this location:
Detail showing all Nightfire detections for March 5 - March 11 over Gulf of Thailand. All but one of these sources (see below) is persistent, occurring on multiple days; they are probably gas flares at offshore oil platforms.
Location and temperature information for the only single-night combustion source detected in the Gulf of Thailand near the expected flight path. Fire detected by VIIRS on March 8 at 18:36 GMT, 21 hours after last ATC contact with the flight.  A persistent multi-night combustion source 11 nautical miles north-northwest of this location is probably a large manned oil platform.




Western Deviation -- we found three single-night combustion events detected by VIIRS in very rugged, remote, forested areas along our approximation (red line) of the supposed western deviation from the flight path:

Nightfire detections of combustion sources along the supposed western deviation (approximated by red line) from the flight path. Dark green shows large areas of thick forest.

Isolated, single-night combustion source on a remote peak in rugged forested terrain of western Malaysia, detected by VIIRS on March 8 at 18:36 GMT.  See below for location.
Location and temperature information for combustion source shown above.
A second isolated, single-night combustion source in rugged forested terrain of western Malaysia, detected by VIIRS on March 9 at 18:18 GMT.  See below for location.
Location and temperature information for second combustion source, shown above.
A third single-night combustion source on a peak in rugged forested terrain of western Malaysia, detected by VIIRS on March 9 at 18:18 GMT.  See below for location.
Location and temperature information for third combustion source, shown above.

Cambodia -- if Flight MH370 actually crossed the Gulf of Thailand and came down on land somewhere along the expected flight path to Beijing, there are large, remote blocks of dense forest where it could have "disappeared."  We found several single-night combustion sources in Cambodia that meet these conditions, and show one of these below (to repeat, we have not done an exhaustive analysis, and are providing this work only as an example of what can be done with publicly available satellite data -- and what we hope is being done, in a rigorous and systematic way, by the authorities conducting the search):


Nightfire detections for March 5 - March 11 along expected path of Flight MH370 (approximated by orange line) as it traveled from Kuala Lumpur to Beijing. Heavily forested areas are dark green.
Location and temperature information for a combustion source detected by VIIRS on March 8 at 18:34 GMT, on a densely forested, isolated ridge in north-central Cambodia, shown above. 

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