The days passed quickly at EROS, and I enjoyed the new surroundings and the concentration I was able to muster to look at one piece of work. Gray set me up at a desk that was currently vacant, and had the luxury of a window on to the east of the vast office block. From my window two huge golf balls loomed, containing earth observation receivers that were downloading data from satellites passing overhead. The grass was neatly cut and the drains and culverts, the clipped trees and shrubs made it a pristine parkland. It was still close to nature and I would sometimes glance out to see an eagle soaring overhead. Once I saw three large brown birds. At first I struggled to recognise them; they reminded me of some of the larger birds I knew from African safaris. A colleague of Gray who was sharing my office seemed surprised I did not recognise them as they were wild turkeys. I was used to turkeys being fat waddling farmyard creatures with garish plumage and wattles and seemingly completely paranoid about the world. No doubt with good reason as they almost all end up on someone’s dinner table.
These birds were pensive, yes, but also deliberate. They strolled across the clipped grass, pecking at whatever they could find. And they looked like real birds rather than lumps of meat with feathers. They had the main features of their domestic cousins, the long blue necks and wattles, but their bodies were much more streamlined and with the plumage more akin to pheasants than turkeys, with black backs but brown under feathers and a black and white pattern on their wing tips.
Gray took me over to this parkland area one afternoon after lunch. There was still a stiff breeze but the sun was out and as long as you kept walking you avoided hyperthermia. The EROS estate included a lake and wildfowl area. I had noticed how South Dakota was not just cultivated fields and cattle ranches; there was significant wild land here. Sometimes it might only be a small patch in the corner of the farm where a creek meandered so much no mechanised farm equipment was able to get in. As well as those there were plenty of reserves. I’d also noticed that when I arrived at Sioux Falls, in fact when I was in Dallas, that many of the people coming to South Dakota were hunters. They flew with their dogs, they were travelling in camouflaged fatigues, and when my suitcase came round the carousel in Arrivals, it was accompanied by plenty of large long metal cases carrying shotguns. South Dakota was a huntin’ an’ a fishin’ state and when
driving back and forth to EROS I did see some guys (they were all men) stalking across the fields towards a clump of woodland.
Maybe the thought of what is to all intent and purpose like a library of satellite images is not exciting to you, but it should be. I know I was being all nerdy, but the thought should enter your head that this room contained the history of the earth since the 1960s, and not just a selective biased account from a bunch of opinionated historians, but a systematically collected dataset that uniformly recorded the reflectance of the earth’s surface for many years. To interpret the whole dataset would take longer than life itself has been on the planet, and the archive grows faster than anyone can absorb it, but to know it is there to be referred to is mind blowing. Snapshots of life on earth are all there – the seasons in every landmass, the swirling weather systems, the human footprint ever growing, the disasters, the ebbs and flows, the stases.
Well it blows my mind.
After the tour and some more work, I knocked off a little early as my energy levels had flagged with jetlag, but I thought some fresh air would be good for me before the sun went down. When I came out of the building, I realised the snow had vanished but there were still grey skies and bitterly cold winds, and I put the heater on full blast in the car as I drove back to the city.
Some of the earliest satellite imagery exists in these folders
EROS Data centre is the location of possibly the largest archive of satellite imagery in the world. It was built in the early 1970s when satellite imagery was starting to be collected routinely at the global scale, and one of the USA’s most ubiquitous sources of satellite imagery had been Landsat. I had used it ever since I learnt how to be a remote sensor in the early 1990s. They chose Sioux Falls because they wanted a location which was relatively central to the North American continent to capture the data and download it as the satellites passed overhead. Not only did they download the imagery, but they archived it, and copied it for others to use. I remember waiting weeks for data to arrive on large spools, then tape cassettes, then CDs and DVDs. Now mostly it can be downloaded from the internet.
The storage of all those data was a massive challenge to EROS – especially since those satellites kept on just collecting day and night (even at night you could obtain radar and thermal images). Underneath the building a basement capable of resisting a nuclear explosion was created and Gray took me down there as part of my tour. Big parts of it were now empty, but at one time, Gray said, he could remember when every inch was covered in shelf after shelf of cassettes or spools. Now, he joked, we might as well set up some bowling alleys down here. Later he took me upstairs and looked through bullet proof glass at a large room which contained just two large supercomputers. They now contained many times more data than the large basement had ever held in the 1990s.
Back down in the basement, though, was a fascinating archive of the oldest imagery. There were plastic and metal canisters that contained original film from the early satellites, including from US surveillance forays of Russia and China with the Corona satellite. The images were parachuted back to earth on film negatives. Along another row we came across envelopes of the original Landsat MSS imagery again with negatives in. Gray knew his way around many of these shelves, he was an old remote sensing hand and had spent many an hour searching for imagery he wanted along the aisles. But when I looked up and down the shelves I saw they disappeared several hundred feet off into the gloom. Even now, the physical archive was enormous, and the USGS had not got around to digitizing the whole lot.
Archive stretching into the distance
I saw the sign off for the EROS data centre for the next turning up ahead, and even in the gloom I could tell I was in the right place. I could see the huge water tower of the complex that had the letters E.R.O.S written across it. I turned up this road for about a mile and then turned into the complex itself. Gray had warned me that I was going to get the third degree of security. I had my passport ready. I was asked to open the bonnet and trunk and step outside the vehicle, so I hurriedly put on my fleece and stood out in the biting wind. I tried to stand behind the booth out of this gale but it swirled round me nevertheless. I was handed a pass to get in the car park and kindly directed down to the reception. I parked up and hurried over to the entrance and found myself in a huge space that looked like an underused airport. I was given a pass and asked to wait for Gray to arrive. I was a bit surprised it was my other colleague Matt who came up the corridor to find me.
The building was huge and mainly on two levels above ground. The central corridor contained an amazing array of spacecraft, all shiny metal and foil just like in the movies, and the walls were adorned with the most colourful and patterned satellite imagery of every sort from around the world. We passed by the canteen at the far end of this gallery and Matt led me off to one side to his office. He did have his own office, it was not particularly open plan in this part, but it was in the central part of the building so he had no window. He just sat there with huge computer resources, a window on to the rest of the world, as it were. It was useful to start my work with him as he was running searches for all the imagery I might need for the job in Sierra Leone. Whereas I had some access to free imagery from outside, he could access the whole archive and because I was working for the US government, hand it over for free.
Gray walked in and we greeted each other like old friends. The previous times I had met the both of them had been out in Freetown, and it was so nice to find them in their own habitat. We chatted about the times we had had, started to work out my schedule for the week and what Gray had to show me to get me up to speed. Gray also said he didn’t want to tax me too much on my first day, especially with the jetlag, but was arranging a tour of the EROS centre.
Gray had suggested not to rush in on the first day, so I planned to head to the EROS data centre around nine. One of the reasons I had my car was the centre is in the middle of nowhere, about 10 miles north of Sioux Falls city. Gray lived in another town altogether, and Matt lived out the opposite side of Sioux Falls so I could not rely on lifts.
The hotel had a certain culture. It was another one of these universal brands that once you had decided you could stay in it you had the system worked out wherever you travelled. There was no dining room, no breakfast service, you were in a motel and the “suites” element was less it was a number or rooms, but more you could cook for yourself. Having arrived near midnight the night before, I had not managed to get anything, so had a few cups of filter coffee from the complimentary drinks selection in my room and hoped that lunch was not too far away. I saw there were machines and a small shop to buy things from the hotel but they looked horribly overpriced and I decided I would wait to do a supermarket shop when I got back from work.
I stepped out of the hotel to icy blasts. The snow was lying but thin on the ground but the roads had been well gritted. I carefully drove up I29 to its junction with one of the great routes of the US, the I90 which goes from Seattle to Boston and at over 3000 miles is the longest Interstate in the US. I followed this for just a few miles before coming off at my junction. There is very little else down this road so I was not too surprised to see the turning signed to the EROS data centre itself.
I now headed north on this ordinary tarmacced road, it rose steeply from the Interstate. I was a little surprised to see how undulating the country was. My impression was the plains were flatter than this. Gray would of course explain this to me later.
The road bounced over several hillocks and although it was still snowing I could make out just how rural this landscape was. There were just a handful of farms, a couple of other homesteads or houses along the route. Every mile I came to a junction where a road would go off at right angles; sometimes I stopped at the junction, sometimes the incoming road gave way. I saw a few cars coming towards me, there seemed to be a few more heading my direction. The sky was grey and still full of snow and I wondered whether I had arrived on the first day of winter and my trip to Sioux Falls was to be completely snow bound. I looked down this straight road with the snow starting to gather on each verge, a long wire fence reaching off into the distance, and I could not help thinking of Fargo. This was the film not the place, but the city from which the film took its title was only about 200 miles north of where I was driving.
Just that hint of “Fargo”
And yet, I went to one place in the States where I came to the conclusion its residents really did have no need to travel further. At one time they had struggled to make their landscape inhabitable and productive, and now they had got it just right there was no need to go spoiling the balance. Once home there you would be happy.
The location of this Shangri-La may surprise you. It is South Dakota.
I never dreamed I would go to South Dakota, but the opportunity arose out of the work I had been conducting in, of all places, Sierra Leone. I’d worked with the US Forest Service out there who were interested in measuring the impact of my project in terms of the land use changes over a period of time since the project had started. The whole point of the project was to protect the forest there that was being decimated by logging, charcoal burning, shifting cultivation and climate change. They wanted me to map various parts of the region to see the different effects, look for trends and see whether protection had improved the forest, or at least decreased the rate of decline. To do this I was to use similar techniques similar to a great colleague of mine who had also worked with me out in West Africa, Gray Tappan.
Gray, and his colleague Matt Cushing worked for the US Geological Survey, one of those huge federal monoliths that even to many laymen in the US would be a household names. They made so may maps people used, recorded earthquakes, mapped the vegetation, rivers, geology, climate and all sorts. I knew of them from the time I started as a geographer at Durham University at the age of 18, and when I was working for NRI and started using satellite imagery, I found myself ordering data from the USGS Center for Earth Resources Observation and Science, or the EROS Data Center, in Sioux Falls. Now I was being asked to go there to learn Gray’s techniques and start my work on Sierra Leone in their offices. As a geographical geek it was like going to the Vatican, the Taj Mahal, the Forbidden Palace. This was my Mecca.