Road to Ubar Pa - Nicholas Clapp [29]
"Any chance of a peek?" I wheedled. "Just a quick peek?"
"Let me see what I can do," Ron replied, ever good-natured.
The next afternoon, Ron cleared George Hedges and me through JPL security and led us to the Image Processing Lab. Its heart was a dark, hushed room in which not only the floor but the walls were thickly carpeted. At a dozen or so workstations, planetary scientists were caught in the glow of large color monitors. With a few taps on their keyboards, digital tapes rolled, were routed through a mainframe computer, and became beautifully rendered images of Earth and distant planets and moons.
Settling into our workstation, we were joined by data entry technician Jan Hayada and Bob Crippen, a colleague of Ron's who had a knack for matching wits with space images and coming up with unforeseen data. It was 3:15; we had until 4:00 to see what we could see.
Bob's fingers rippled across the keyboard. Nothing happened. "We're sharing a mainframe Data General," Ron noted. "Lot of people must be on it today. Slows it down." Then (slowly) a series of scans—cyan, magenta, yellow—swept down the screen and produced a high-resolution video image of our corner of far Arabia. "This is a Landsat quarter-scene, sixty kilometers across. False color," Ron explained.
"Bands three, five, and nine," Bob added. "Original plus an eleven-by-eleven high-pass filter. Linear stretch. Standard stuff."
Ron nodded. As a result of "false color" imaging, the scene's gravel plains were rendered in unnatural blues and greens; dunes were painted rich shades of beige, ocher, and brown. We searched the scene: there wasn't a hint of anything man-made.
"Can we take a closer look? Here?" I wondered. Up and to the left was the outline of the ancient lakebed where Bertram Thomas had encountered "the road to Ubar."
"Sure," Bob replied, "It will take a few minutes, though." He centered a cross-hair cursor on the lakebed and typed in a sequence of commands.
We waited. Then, ever so slowly, the image rescanned. And we saw roads. Not one but several roads, coming from the east, crossing the lakebed, then branching off to both the west and the north.
"Fantastic!" George exclaimed.
"Not too shabby." Ron nodded and smiled. We were elated. But then it sank in that some, if not all, of these roads had to be modern, tracks laid down by oil prospectors, military patrols, and by freewheeling bedouin of the age of the Toyota.
"Well, Bob..." Ron mused.
"Well, what?" Bob asked.
"Let's beat up on it," Ron said, a shade grimly.
"We could do an enhancement," Bob suggested, electronic gunslinger eyes narrowing. "Divide one band by another, that sort of thing..."
A dense computer-tech conversation ensued, which I only vaguely followed. Ron theorized that ancient tracks—hammered by the feet of thousands of camels over hundreds of years—would be more compressed than those left by modern vehicles skittering over the terrain. Did this compression have a spectral signature?
Detail of Landsat 5 image
"Hmm," Bob responded. He tentatively tapped his keyboard. "We could also hit up on the near-infrared, shift it to visible." Without waiting for a reply, Bob typed furiously. Then typed some more and rocked back in his chair.
"Hmm, we'll see."
The wall clock at the far end of the room read 3:52 P.M. The image rescanned, now producing waves of color that were surreal, psychedelic. And a strange and curious thing happened. The tracks crisscrossing the image faded away, disappeared. All but one.
Landsat detail after image processing
"Well, look at that," said Bob. What remained on his monitor was a thin black line that arced up across the screen and led off into the dunes of the Rub' al-Khali.
We took turns, like little kids, following it with our fingers.
There it was, before our eyes and in far Arabia, the road to Ubar.
6. The Inscription of the Crows
IT DIDN'T TAKE LONG to come up with an expedition scenario. On the ground we would locate and follow the thin black line that angled across JPL's Landsat