Satellite imagery to show strategic information has been national space programmes primary function from deep within the Cold War. The US ‘Discoverer’ series (CORONA spy satellites hidden behind a civilian name) were the first western Earth-observing systems launched, years in advance of far cruder meteorological imagers (1960) and more than a decade before environmental monitoring started with Landsat-1 (1972).
So what do modern systems say about timeliness of monitoring modern strategic information? What’s interesting about the conflict in Syria is the speed of online delivery systems has a by-product that some of the large-scale activity on the surface are visible in near-real-time to casual users. No dedicated, nor top secret, monitoring system is necessary.
The NASA Terra MODIS imagery from the early pm overpass on 23rd November shows two conflagrations to the SW of Raqqa, the stronghold of ISIS in northern Syria. The pink overlay is a shapefile of the Syrian road network, which are free to download.
These dark clouds of smoke are are most likely from some form of oils storage facilities burning. These could be tankers or larger, static oil tanks. The spatial resolution of MODIS is 250 m, so there’s a lot of smoke with these- the most northerly plume stretches for tens of kilometres. Static containers are most likely
Here’s the MODIS image above, bit as a close up of the fire closest to Raqqa.
Well, what can we tell? The fire is located near a road, but not on one, so it’s infrastructure, rather than transport that’s burning.
How can we investigate further? We need greater spatial resolution. The next (free, unclassified) stage is Landsat. As discussed previously, Snapsat have produced the most user-friendly interface imaginable. Even better, the downloads are now in geotiff format- you can slot them straight into your favourite GIS tool. Landsat has a 17-day revisit cycle. Luckily, there was a Landsat 8 overpass the next day and, most importantly, it was cloud-free.
This is an ‘urban’ 7-6-4 mix, but many other combinations available.
There’s a group of oils storage containers, just from where the smoke is emanating. It appears that only one of the storage cylinders exploded, located in the SW corner of the complex. Here, a day later, there’s still a faint trail of smoke visible. It’s the faint smudge, seen drifting NW.
We can see this in greater detail using the USGS’s Explorer site to add the 15 m spatial resolution band 8.
This is a clearer product spatially, but unlike the multispectral Snapsat product, there’s no atmospheric corrections- it’s raw. This gives a washed out feel. Doing corrections isn’t too hard, but for quick-looks like this, it’s time-consuming. Also the reflectance products from USGS are currently suspended (starting 01/11/15) due to issues with TIR, so that removes another layer of clarity.
A 1:10 000 scale image highlights the superior spatial resolution that to a skilled analyst, or just someone who knows the area, can provide immense information. It could also be that the fire is out and those grey streaks are just an extension of what seems to be a Wadi to the south.
The other source of near-real-time visible data is NOAAView- but that’s available one day later (shows the previous day) and is only 750 m spatial resolution – these sort of applications were secondary or even tertiary considerations in its design. Here is 23rd November mid-afternoon. The clouds of dark, oily smoke are dissipating.
However, there’s still some useful information. In this later afternoon overpass, the fires are still burning, but no new activity can be seen.
What does this set of images tell us? Lots, if you’re an interested party. But at their base-level, they illustrate that high-quality strategic information is available to everyone, if you know where to look for it. Also, they’re easy to obtain: it took longer to write this blog post than to download and process all the images.