David Baxter shifted his weight before continuing his lecture.
“Second, it has superb optics. The Ritchey-Chretien telescope, or folded-mirror telescope, has a main mirror ninety-four inches in diameter. The main mirror is also an engineering marvel, constructed, not of glass, but of an aluminum-coated composite. Thousands of piezoelectric transducers embedded in the mirror permit an onboard computer to warp the surface of the mirror minutely, thereby correcting for any distortions caused by the atmosphere. Once the incoming light is reflected from the main mirror and condensed by the secondary mirror, it passes through a zoom lens that permits a ground-based operator to zoom-in on any objects on the ground of particular interest. On a clear day, the Advanced KENNAN’s telescope has little difficulty in distinguishing objects less than an inch in diameter from an altitude of sixty miles.”
“One inch?” Lazarus exclaimed.
“Yes, sir,” the young man said matter-of-factly. “However, the real marvel is not the lens, but the film, or what is used in place of film. The compartment behind the rear of the telescope contains several photosensors, which give the telescope its phenomenal acuity. Each of the photosensors contains a strip of over ten thousand charged-coupled devices, or CCDs. Acting like the rods and cones of the retina of your eye, the CCDs directly convert the light falling on each element into an electric current proportional to the amount of light. These, in turn, are converted into digital values understandable by the computer that’s part of the onboard image processor. The way it makes a picture is called ‘push broom’ scanning. The satellite’s movement sweeps the strips of CCDs over whatever the telescope is pointing at quite like the way you push a broom over the floor. Thus each individual CCD takes a series of individual readings forming a string of readings which the computers add together to form a complete picture.”
Lazarus gave the young man a puzzled expression.
“I lost you?” David inquired.
“Go over that ‘push broom’ thing again, if you would.”
“Well,” David began. “Look at it this way. Let’s say you wanted to digitize a picture. One thing you could do is to make a matrix of photocells and then project the picture on it. That way you can see the picture quite like a fly would, as a series of individual dots, say one hundred dots wide by one hundred dots high.”
“That’s sort of the way a television works, isn’t it?” Lazarus leaned forward and peered at the computer screen. “Or this thing, for that matter.”
“Exactly,” the young man agreed. “That’s exactly how that computer screen works. There are something like two thousand rows of two thousand dots each. They are called pixels and each is just a dot of light which has a particular color and brightness.”
“Fine, then I understand your point.” Lazarus looked back at David. “Please continue.”
“Well, let’s say that you don’t have a lot of money and you want to save some. One of the things you can do is simply take a strip of a hundred photocells and move it across the picture at a steady rate and repetitively sample the image each photocell sees a hundred times. That way you’ll have the same information, one hundred by one hundred dots, but you only need ten percent of the photocells to do it.”
“I see,” Lazarus exclaimed, “You’ve pushed the strip over the picture like a push broom, except the string of photocells is your broom. That’s why you called it ‘push broom’ scanning, isn’t it?”
“Yes, that’s correct,” David answered, obviously surprised. “Given that the satellite is moving anyhow, it’s a natural thing to do it. There is also another advantage. Instead of having a matrix of one hundred wide by one hundred deep, you can take all ten thousand CCDs, line them up side by side and have a ten thousand dot wide picture by however long you want. That will improve resolution a lot.”
“Ah, yes, how obvious,” Lazarus commented. “And if you have a second set of those photocells right behind the first, but offset by half the width of the individual photocells, you now can combine the information from the two sets of photocells and get a resolution that is actually smaller in diameter than that of the photocell itself, can’t you?”
“Ah, who told you that?” David uttered in shock. “That’s supposed to be a top secret.”
“It’s also obvious to anyone who thinks about it for more than ten seconds,” Lazarus replied with a chuckle. “You can also extend the idea by having several rows of CCDs, I think you called them, each offset slightly from the row in front and get really fine resolution. I’ll bet that’s what you do.”
“No comment, sir,” the young man responded automatically. He was obviously surprised by how quickly Lazarus picked up on the idea.
“You said something about a number of photosensors,” Lazarus suggested, trying to change the subject to put David at ease.
“That’s right, there are several individual photosensors,” the young man answered. “Each photosensor is sensitive to a specific wavelength of light. Besides the usual blue, yellow, and red light in the visual spectrum, several infrared and ultraviolet wavelengths are also measured as well. By recombining the information from all of the sensors, the computers in the onboard image processing equipment not only can determine whether it’s wheat or oats growing in a particular field, but what variety of wheat or oats it is.”
“The variety of wheat?” Lazarus stared at the young man incredulously.
“Certainly.” David looked oddly at Lazarus. It seemed to him that a man who just explained how a satellite could resolve detail finer than what an individual CCD could see should intuitively understand spectral analytical technique. “We combine the information from several wavelengths and perform a spectral analysis quite the same way a chemist would. We can tell how mature a crop is, its health, and even calculate the expected yield when it’s harvested.”
“Well, if you say so, I’ll have to believe you since I never took any chemistry,” Lazarus replied with a shrug and turned to the controls on the workstation. “You don’t sit here and play with this all day, do you?”
“Oh, no, sir,” David said. “Only on special occasions, like this one. That’s maybe three or four times a month. We usually leave the satellite in parking orbit and just watch.”
“How does that work?” Lazarus asked.
“Well,” David began, “this satellite has two modes of operation: survey and close-look. Or, if you prefer to think in terms of a camera, wide-angle and telescopic. Survey mode is the Advanced KENNAN’s normal mode of operation, used while orbiting at about two hundred miles altitude, where the atmosphere is virtually nonexistent. That way we don’t waste fuel. In this mode, the satellite is left to automatically map the surface of the earth continuously in eight-mile or so wide swaths, searching for anything suspicious. It is not under manned- control. The satellite is merely circling the earth, continuously taking relatively low-resolution images of whatever is below and beaming the information electronically via the MILSTAR communication satellites. Mostly, the Defense Mapping Agency uses the images to draw maps.”
“Could you explain just how you get that phenomenal zoom-in effect I just saw?” Lazarus inquired.
“Well, Mr. Keesley,” David Baxter told him. “It’s sort of complicated because the camera is used in two different modes.”
“The survey and close-look modes?” Lazarus guessed. He was watching David with an intensity that left the young man nervous.
“Yes, exactly,” David replied. “You see, in the survey mode, we want to cover as wide an area as possible on each orbit. The view of the camera at that altitude is only about six to eight miles, so it would take quite awhile to cover the whole earth. However, that isn’t the real purpose of the Advanced KENNAN. It can be tilted from side to side on each pass and so cover those areas of the world we are particularly interested in.
“What happens next?”
“Well, the image goes into the optical equipment I just described,” David answered. “With the aid of the onboard image
processing computer while in survey mode, it can resolve objects as small as three feet. That is to say, it can spot a man lying down in the grass and show him as a blob on the screen, but it won’t see the dog with him unless it was quite large.”
“How about the close-look mode?” Lazarus prompted.
“Well, in that case, the satellite is deorbited slightly so that it will pass as low as sixty miles over whatever we’re interested in. Also, the camera is switched to close-look mode. Essentially, all that happens is the zoom-lens system comes under human control via a satellite data link. You just did that yourself a couple of minutes ago. The operator can watch live, real-time images as the satellite takes them, and then adjust the orientation of the satellite with small computer-controlled thrusters to point at whatever he is interested in. He can also use the zoom lens to take a really close look as well.”
“That’s what those joysticks do, isn’t it?” Lazarus pointed to the controls he had played with a few minutes earlier.
“Yes,” David replied. “Given that the satellite is almost three times closer than normal to its target and the zoom-lens is set at high magnification, the resolution is far greater than in survey mode. That gets the resolution down to about one centimeter, or about a half-inch, on a really good day. That’s roughly the quality of a snapshot taken at a hundred feet in the air.”
“Snapshot taken a hundred feet in the air? You mean like taken from a helicopter?” Lazarus frowned in confusion.
David Baxter smiled. “One day I paid a hundred bucks to ride in a hot air balloon. Naturally, I brought along a camera, just a little 35-mm snapshot camera. Boy, was I surprised when I saw the results. I got about the same level of detail from the snapshots I took at a hundred feet as I get on that color monitor behind you. You can clearly make out if someone is a man or a woman, and how they are dressed. You can also tell the color of their hair and whether the man has a beard or not, but you can’t positively identify the person unless they have some large identifying mark, like a birthmark on the forehead.”
A beeping sound interrupted him.
“Excuse me, sir,” David Baxter said anxiously, “but we’re being watched.”
“Watched!” both Jonathan Boswell and Lazarus Keesley exclaimed in unison. They first glanced at each other and then began searching the room for the hidden camera.
“I meant that the Russians are watching our satellite with radar,” David explained meekly when he saw their reaction. “If I can sit at the controls, Mr. Keesley.”
Lazarus hurriedly relinquished the computer workstation’s chair to the young man. David Baxter quickly set to work and began typing on the keyboard.
“I’m just making certain that the piezoelectric shutter is turned on,” David told them while he typed. “I don’t want a laser blinding my bird, if I can help it.”
“What?” Lazarus muttered.
“Never heard of piezoelectric shutters, have you?” David inquired.
“No.”
“Well, I don’t know exactly how they work, but they’re great,” the young man noted. “They can react to a flash of light in a split instant, so fast that they can detect and react to a laser before it can hurt the optical equipment. I once got to try one of those special helmets our bomber and fighter pilots wear. They have piezoelectric goggles built into them to prevent the pilots from being blinded by lasers and atomic blasts. They’re fantastic. Someone flashed a camera at me from just a few feet away, and all I saw was the faint glow of the filament after the actual flash was over.”
“I see,” Lazarus said dubiously. “But you’re afraid that the Russians might shoot a laser at us?”
“They’ve done it in the past,” David answered as he studied the screen. “And they’re more than normally interested in us right now.”
“What?” Jonathan Boswell uttered.
“Well, sir,” David replied. “Usually they just paint us with their early warning radars. Right now they have about ten separate radars on us.”
A warbling sound interrupted him. “Lock-on! Those sonsofbitchs have a fire-control radar locked-on us.”
“Are you sure?” Boswell demanded.
“Certainly, sir. All our birds have radar detectors on them now. The Air Force intelligence people came over last month and played the tapes of the signals from the satellite that the Russians blinded over Siberia a couple of years ago. They said that warbling sound was from a fire- control radar. Do you want me to abort the mission? I’d better warn you that the piezoelectric shutter didn’t help the Air Force’s bird over the Siberia. That laser was so powerful that it burned a hole through the satellite’s outer skin.”
“No,” Director Boswell snapped. “If they shoot, it’s an act of war. We’re supposed to be at peace.”
David nodded and started to type again. Suddenly, the second screen was filled with a stationary view of earth.
“That’s our target area, the Gomazal Valley,” the young man explained. “That view was taken from the last run, which was in scan mode. Everything of interest is marked on it so when I get a look at that valley, I’ll be certain to check out all the important stuff in look-see mode.”
“How can you find that one valley among all the others?” Lazarus asked while he watched the two screens. One screen was static, showing a sixty-square mile section of eastern Iraq. The other showed the real-time, live view from the Advanced KENNAN.
“The computer will automatically guide that camera, once we’re in visual range of the Gomazal Valley,” David explained. “In fact, it will even automatically conduct the first scan of all the marked targets for me. I get to play with the controls only after that is done. My job is to spot whatever was missed before. Usually there’s something.”
“How much longer?” Director Boswell inquired.
“About two minutes,” David Baxter replied. “We’ll have about five minutes to do the survey and look-see.” The room fell silent as they clustered around the screen and watched. Lazarus recognized the Black Sea coast of Turkey slip by. He could easily spot the smaller towns as well as the cities and the occasional glint of a river.
“What time is it there?” he asked quietly.
“About eleven-thirty in the morning,” David told him. “That’s awfully late. We normally want the sun to be fairly low in the sky so we can see the shadows. It helps to judge heights. Also there’s less air pollution in the morning. However, this is a rush job, so we’re taking the first available bird down for a look-see.”
The view shifted as the camera aimed forward.
“The computer has just spotted the target area,” David explained. “It will keep the camera automatically aimed at the area while we’re in view, or until I take manual control. Let’s get a close up.”
He moved the left joystick. The camera zoomed-in on the still distant valley. “What the hell!” David exclaimed.
Then Lazarus saw it. A small flash, then another and another appeared on the screen. At first, he thought that it might be a laser being fired, but then he realized that the flashes were scattered all over the scene. Clouds began to grow.
“David, what is it?” Jonathan Boswell demanded.
“Those sonsofbitchs are putting up some sort of a smoke screen. They don’t want us to see what they’re doing in that valley.”
Chapter Eighteen
“Don’t stop.”
“What?”
“Please don’t stop humming, my love. I enjoy it,” Jerry murmured while he caressed Madeline’s hair. Laying together the dark, she hummed gently as she cuddled close to him, drawing her breast across his chest. A shiver of pleasure ran through their bodies. A contented smile appeared on Jerry’s lips when he remembered their first time together.
“Hungry?”
“Huh?” he grunted as Madeline broke his reverie.
“I asked if you were hungry,” Madeline said as her stomach growled.
“Hungry?”
“Yes, my sweet prince,” she purred
. “We haven’t had dinner. And now it’s after three in the morning.”
“You’re hungry?” Jerry asked while stroking her back.
“Not really,” Madeline replied while she nibbled his ear lobe. “This tastes good! I think I’ll just eat you instead,” she squealed in delight. She licked his face and, finding his lips, kissed him, holding him tight.
“Lordy, lord, woman!” he exclaimed when she finally released him. “Where did a lady scientist get all that passion?”
“It’s the Irish in me,” she answered, settling her head on his shoulder again. “My mother was Irish; I’m half Irish and half Scottish.”
Jerry laughed aloud. “Madeline,” he whispered a moment later. “I realize that I’m still a married man, and this is our first date and all, but will you marry me?”
“No,” she replied instantly. Sensing his body stiffen in response to her rejection, she pressed herself against him. “I don’t want to lose you, ever. Now that I found you, I’m not letting go.”
“But I want to marry you,” he protested.
“That’s just the point, Honey. Marriage and I don’t mix. I’ve tried it twice and watched it destroy both relationships. I’m not going to make that mistake a third time. No! Never!”
“I don’t understand.” Jerry stared at her.
“I’m not giving up my work.” She hesitated before adding, “Nor do I want you to give up your flying.”
“And not being married makes a difference?”
“Yes,” she insisted. “Being not married will make us want to be together when we can, not force us to be together because we are married.”
“What?” He had obviously failed to see her logic.
“Well, it’s true!”
“That assumes that we’re living apart. You’re making assumptions a beautiful lady scientist shouldn’t make.”
“What assumptions?”
“Well, one of them is that I’ll continue to fly,” he said. “That’s almost all over. I’m on my last hurrah, and I know it.”
The Espionage Game Page 17