As an advisor to the Dept. of Defense (DoD) on issues of advanced technology, I have been called into observe or test or evaluate a number of advanced weapons systems and other combat related new technology equipment. Let me tell you about the latest I investigated in Iraq and Afghanistan.
I was asked to evaluate the combat durability of a new multi-use sensor and communication system that can be deployed from an aircraft. I was flown to Baghlan and after a days rest; I was invited on a flight in a C-130. We flew north east over the mountains near Aliabad and approached an outpost base near Khanabad. Just before we landed, we were vectored to a large flat area just north west of the base. The ramp on the C-130 was lowered and we all put on harnesses. A man in combat fatigues carried a large canvas bag to the real of the ramp and pull out one of several devices from the bag. It looked like a small over-inflated inner-tube with two silver colored cylinders on top. It had several visible wires and smaller bumps and boxes in the hub and around the cylinders. It looked like it was perhaps 16 to 18 inches in diameter and perhaps 6 inches thick. The man pulled a tab which pulled out what looked like a collapsible antenna and tossed it out the ramp. He then took others out and did the same as we flow in a large circle perhaps 20 miles in diameter – over this flat plain near the camp tossing out 12 of these devices and then a final one that looked different. We then landed at the base.
I was taken to a room where they gave me a slide show about this device. It was called Solar Eye or SE for short. The problem they were addressing is the collection of intelligence on troop movements over a protracted period of time, over a large geographic area. The time periods involved might be weeks or months and the areas involved might be 10 to 25 square miles. It is not cost effective to keep flying aircraft over these areas and even if we did, that covers only the instant that the plane is overhead. Enemy troops can easily hide until the plane or drone is gone and then come out and move again. Even using very small drones gives only a day or two at most of coverage. The vast areas of Afghanistan demanded some other solution.
Stationary transmitters might work but the high mountains and deep valleys make reception very difficult unless a SATCOM dish is used and that is so large that it is easily spotted and destroyed. What was needed was a surveillance system that could monitor movements using visual, RF, infrared and vibration sensors. It had to be able to cover a large area which often meant that it had to be able to look down behind ridge lines and into gullies. It had to be able to operate for weeks or months but not cost much and not provide the enemy any useful parts when and if they found it. This was a tall order but those guys at NRL figured it out. Part of why I was called in is because I worked at NRL and a few of the guys there knew me.
After lunch, we got back to the lecture and I was finally told what this device is. When the device is tossed out, a tiny drogue chute keeps it stable and reduces its speed enough so it can survive the fall. The extended antenna helps to make it land on its bottom or on its side. If it lands on its side, it has a righting mechanism that is amazing. The teacher demonstrated. He dropped an SE on the floor and then stepped back. What I thought was a single vertical antenna was actually made up of several rods that began to bend and expand outward from a single rod left in the center. These other rods began to look like the ribs on an umbrella as then slowly peeled back and bent outward. The effect of these rods was to push the Se upright so that the one center rod was pointing straight up.
When I asked how it did that, I was told it uses memory wire. A special kind of wire that bends to a predetermined shape when it is heated in this case by an internal battery. After the SE was upright, the wires returned to being straight and aligned around the center vertical rod.
OK, so the device can right itself now what? I said. The instructor referred me back to the slide show on the computer screen. I was shown an animation of what looked like a funny looking balloon expanding from the center of the SE and inflating with a gas that made it rise into the air. He was pointing to the two cylinders and the inflatable inner tube I had seen earlier. The balloon rises into the air and the animation made it appear that it rose very high into the air thousands of feet high.
The funny looking balloon was shaped like a cartoon airplane with wings and a tail with some odd panels on the top of the wings and tail. I finally said I was tired of being spoon fed these dog and pony shows and I wanted to get to the beef of the device. They all smiled and Ok, here is how it works.
The SE lands and rights itself and then those rods which were used to right it now are rotated and sent downward thru the center of the SE into the ground. They have a small amount of threaded pitch on then and when rotated, they screw into the soil. While they are screwing into the hard ground, they are also being bent again by an electrical current that is making them bend in the soil as they penetrate. The end result looks like someone opened an umbrella under ground beneath the SE. Since these rods are nearly 3 feet long, they anchor the SE to the ground very firmly.
The cylinders then inflate a special balloon that is made of some very special material. The Mylar is coated with a material that makes it act as a solar panel, creating electricity. The special shape of the balloon not only holds it facing into the wind but it also keeps it from blowing too far downwind. Sort of like the way a sailboat can sail into the wind, this balloon can resist the upper level winds by keeping the tether as vertical as possible. The balloon rises to between 5,000 and 15,000 feet depending on the terrain and the kind of surveillance they want to do. It is held by a very special tether.
I was handed a tangled wad of what looked like the thin fiberglass threads that make up the cloth used for fiberglass boats. It was so lightweight that I could barely feel it. I had a wad about the size of a softball in my hand and the instructor told me I had nearly 2,000 feet in my hand. This tether is made from a combination of carbon fibers and specially made ceramics and it is shaped like an over-inflated triangle. What is really amazing is that it is less than one centimeter wide and made with an unusual color that made it shimmer at times and at other times it seemed to just disappear. The material was actually very complex as I was to learn.
The unique shape and material of the tether uses the qualities of the carbon fiber coating and metallic ceramic core to provide some unusual electromagnetic qualities. The impedance of the tether as seen by the RF signal in it is a function of the time-phased signal modulation. In other words, the modulation of the signal can cause the tether to change its antenna tuning aspects to enhance or attenuate the RF signal being sent or received. Using the central network controller, all of the SEs can be configured to act as alternating transmitters to other SEs and receivers from other SEs. This antenna tuning also comes in handy because every SE base unit also can function as a signal intelligence (SIGINT) receiver collecting any kind of radiated signal from VLF to SHF. Because the antenna can be tuned to exact signal wavelengths and can simulate any size antenna at any point along its entire length, it can detect even very weak signals. The networking analysis system monitor and processor (SMP) records these signals and sends them via satellite for analysis when instructed to do so by the home central command.
The system combines the unique properties of this tether line with three other technologies. The first is an ultra wide-band (UWB) high frequency, low power and exceptionally long range transceiver that uses the UWB in a well controlled time-phase pulsed system that makes the multiple tethered lines act as a fixed linear array despite their movement and vertical nature. This is sometimes called WiMax using a standard called 802.16 but in this case, the tether functions as a distributed antenna system (DAS) maximizing the passive re-radiation capability of WiMax and making maximum use of the dynamic burst algorithm modulation. This means that when the network controlling system monitor determines that it is an optimum time for a specific SE to transmit, it uses a robust burst mode that enhances the power per bit transmitted while maintaining an optimum signal strength to noise ratio. By using this burst mode method in a smart network deployment topology, the SE overcomes the limitations of WiMax by providing both high average bit rates and long distance transmissions allowing the SEs to be spaced as much as 100 miles apart. The SE tethers function as both a horizontal and vertical adaptive array antenna in which MIMO is used in combination with a method called Time Delayed Matrix-Pencil method (TDMP) to distinguish direct from reflected signals and to quantify phase shifts between different SE tethers connected to the system monitor. This creates a powerful and highly accurate Direction of Arrival (DOA) capability in very high resolution from nano-scale signal reflections.
Combining the precision DOA capability with an equally precise range capability is accomplished using the time-phased pulse which creates powerful signals that are progressively sent up the tether and then systematically cancelled out at certain distances along the tether using destructive echo resonance pulses. The effect is to move the emitted signal from the bottom of the tether along the tether as if it were a much shorter antenna but was traveling up and down the height of the tether. Since effective range is directly proportional to the height of the transmission, this has the effect of coordinating the emitted signal to distance. Using the range data along with the DOA, every detail of the surrounding topography can be recreated in the computers imaging monitor and the processor can accurately detect any movement or unusual objects in the field of coverage.
The second adapted technology is loosely based on a design sometimes referred to as the Leaky Coax or ported coax detector. The unique metallic Mylar and conductive ceramics in the tether give the electrical effect of being a large diameter conductor making insertion losses almost zero while allowing for an optimum pattern of non-uniformly spaced slots arranged in a periodic pattern that maximizes and enhances the radiating mode of the simulated leaky coax. The idea is that the emitted signal from one SE is coupled to the receiver in adjacent SEs in a manner that can be nulled out unless changes are made in the area in which the emitted signal is projected. The advantage of using the ported coax coupling method is that the signal needed for this detection process is very low power partly because the system makes use of the re-radiation of the signal in sort of an iterative damper wave that maximizes the detection of any changes in the received direct and reflected signals. In simple terms, the system can detect movement over a very large area by detecting changes in a moving temporal reference signal if anything moves in the covered area. In combination with the ultra wide band, spread spectrum transceiver, this detection method can reach out significant distances with a high degree of accuracy and resolution.
The third adapted technology is loosely based on magnetic resonance imaging (MRI). MRIs are used to detect non-metallic and soft tissue in the body by using a method that blankets the subject in a time-phased magnetic field and then looks for minute timed changes to reflections of that magnetic field. In the case of the SE, the magnetic field is the WiMax, ultra wideband time-phased signal emitted by the tethers. It can blanket a large area with an electromagnetic field that senses changes in the signal reflection, strength and phase so that it can detect both metal and non-metal objects, including humans.
Variations on these three technologies are combined with a networking analysis system monitor and processor (SMP) that can receive signals and control the emissions from multiple SEs and process them into intelligence data. The system uses a combination of wires and lasers to speed communications to and from the SMP and the SMP can use any one or all of the SEs for selective analysis of specific geographic or electromagnetic signals.
Finally there is the balloon. It rises up above the clouds and sits in the bright sun. It has a surface that performs several functions. The outer layer acts sort of like the reverse of automatic dimming sunglasses. That is, it turns a pale blue under bright direct sunlight but it gets darker and darker as the light dims so that by the time the sun is down completely, the balloon is almost black. Although moon light does cause it to slightly brighten in color, the moon light is so direct that it only affects the top and most the bottom half remains black. During the day, the balloon is one to three miles up and is almost impossible to see without binoculars and knowing exactly where to look. During the night, the only way to know it is there is to see the stars that it blocks but at the long distances, it only blocks a very few stars at a time so again it is nearly impossible to see it. Since the tether is also nearly invisible, you have to be standing right next to the SE to be able to see any of it.
Just under this outer coating is a layer of flexible solar sensitive material that acts as a giant solar panel. It produces about 25 watts of power at peak performance but the SE system uses only about half that so the rest charges a Lithium-Cobalt Ion battery in the SE base unit. This is more than enough to power the system at night with enough left over to cover several cloudy days.
The bottom half of the balloon is coated with a reflective Mylar facing the inside of the balloon while the upper half of the balloon does not have this coating. This creates a reflective collection surface for RF signals being sent to and from satellites and high flying planes. Inside the balloon are antenna elements in this semi-parabolic reflector of several feet wide making it easy to send and receive signals at very low energy levels. The SHF signals being sent are brought to the balloons internal antenna by superimposing them on top of the UWB signals on the carbon fiber Mylar surface of the tether. This is done with remarkable efficiency and hardly any signal loss.
Now that I had gotten the entire presentation, I was taken back into the C-130 where there was a small desk with a computer monitor and other equipment. The screen showed a map with the 12 SEs marked with red blinking dots. An internal GPS provided exact positions for both the SE base units, the central network SMP and the balloons. Beside each red dot was a blue dot off to one side showing the relative position of the balloon. Around each red dot was a light-blue circle that represented the coverage area each light blue circle overlapped two or more other coverage area circles. Finally, there was a larger light yellow circle around all of the SEs showing the coverage area of the central networking SMP that dropped near the center of the SEs. Altogether, these circles covered an area of about 100 square miles but were capable of coverage over three times that area.
The operator then flipped a few switches and the screen changed over to what looked like an aerial monochrome view of a 3-D topographical map showing the covered terrain in very good detail using shading and perspective to relate the 3-D effects. Then the circles on the screen began to pulsate and small lights appeared on the screen. These lights were different colors red for metal objects, blue for animals or people and green for anything else that was moving or was inconsistent with the topography. It was programmed to flag anything that MIGHT be unusual such as objects that had sharp corners or smooth rounded edges or a symmetrical geographic pattern. When the operator moved a circular cursor (trackball) over any of these objects, the data lines on the bottom of the screen would fill with all kinds of information like its speed, direction, height above ground, past and projected paths, etc. Once an object was hooked by the trackball, it was given a bogie number and tracked continuously. The trackball also allowed for zooming in on the bogie to get increased detail. We spotted one blue dot and hooked it and then zoomed in on it. It was about 4 miles outside the SE perimeter but we were able to zoom in until it looked like a grainy picture from a poor signal on an old TV set. Despite that detail, it was clear that the object was a goat actually a ram because we could see his horns. Considering it was about 1 AM at night and this was a goat that was 69 miles from where we were and 4 miles from the nearest SE, that is resolution that was incredible.
We zoomed out again and began a systematic screening of all of the red, blue and green dots on the screen. For objects the size of cars, we could reach out more than 40 miles out from the ring of SEs. For people, we could reach out about 15 miles outside the ring but inside; we could see down to rabbit size animals and could pick out individual electrical power poles and road signs.
I was shown a map of the other locations when the other Solar Eye arrays were located and their coverage areas. This is the primary reason and basis for the upcoming Marjah campaign into the Helmand Province a huge flat plateau that is ideal for the invisible Solar Eyes.