Radar Surveillance

Airborne Surveillance Systems Against Sea Pollution

For more than 15 years, Air Atlantique has been using the Terma surveillance systems to combat oil pollution at sea.


Three new Airborne Surveillance Systems were delivered to Air Atlantique in Coventry, UK, in the past 10 years. The most recent system was delivered in 2002.

For more than 15 years, Air Atlantique has been fighting the oil pollution at sea. Old DC3 aircraft are used for spraying oil slicks with chemicals, when possible, but first the oil polluted area must be identified. This is accomplished with the Terma surveillance system. Air Atlantique has detected oil pollution, traced polluters and assisted in clean-up operations in numerous countries around the world.

The Terma Surveillance System may be installed in small twin engine, as well as larger aircraft. It can include several sensors. The main sensor is the Side Looking Airborne Radar (SLAR) which is able to detect oil pollution at a distance of more than 20 Nautical Miles on each side of the aircraft. This sensor enables one aircraft to cover an enormous area in a short time.

Identification of a polluted area is followed by an examination of the oil slick and, if possible, the tracing of the polluter.



In examining the oil slick more sensors may be employed. The IR/UV-Scanner outlines the exact shape of the spill, but provides little indication of the amount of oil in it. To determine the amount and the location of the thick part of the oil spill, requires the MicroWave Radiometer (MWR). This instrument provides a map of the oil slick, determines the thickness of various areas of the slick, and calculates the total amount of oil in it. Cameras are used (Photo/Video) to provide additional information about the spill.

All images from the sensors are stored, including navigational data, and may be printed out, either in the air or later at a Ground Station. The polluter is not always found, but if he is seen, various cameras may provide photographic evidence for subsequent prosecution. The photographic equipment may include still, video, LLL-Cameras and Night Cameras, but all of themmust provide annotation from the aircraft navigational system, specifying date, time, position, altitude, heading, etc.

The TSCS software is an easy-to-use window program. It is implemented on the Windows NT operating system. The man-machine interface is presented on a high-resolution 20" monitor. This software provides the functionality to handle mission administration and all necessary functions for acquisition and data collection/presentation for all the sensors.The data may be post processed at a ground station. The complete airborne system is delivered in one rack/console in which all cabin equipment is mounted. This configuration allows for easy dismounting of all equipment for maintenance of aircraft or for other configuration of flight. The workstation, as shown in the picture, can be installed in much smaller aircraft's than shown here.

Terma has delivered this kind of system in many areas of the world in the past 20 years, and with intensified focus on the environment in nearly all countries, the demand will increase in the future.

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://www.terma.dk/index.dsp?area=294#

MOSKIT AIRBORNE RADAR

The Moskit airborne radar is intended to equip light and medium fighters, in particular to replace the Sapfir-23 airborne radar, and makes it possible to convert the MiG-23 fighter into a sophisticated powerful multifunction aircraft capable of conducting air defense and delivering attacks against ground and sea targets.

There are two versions of modernization of the aircraft with the Moskit airborne radar. The first version involves replacing the Sapfir-23 airborne radar or its modifying with the Moskit-23 radar to be installed in the aircraft nose section in place of the main monoblock unit (antenna, receiver, transmitters of the main and illuminating channels of the Sapfir-23 radar). In addition to the main operating modes of the Sapfir-23 radar, the Moskit-23 radar features the following operating modes: - air-to-air operating mode: surveying/ranging and tracking; while-scan tracking eight targets and simultaneously engaging two of them; close air combat; - air-to-surface operating mode: ground mapping while searching for ground (sea) targets by the following methods: scanning beam, Doppler beam narrowing, antenna aperture synthesizing; detection of moving ground (sea) targets; ground ranging.

The Moskit-23 airborne radar is interfaced with the upto- date R-27R(T), RVV-AE and R-73 air-to-air missiles and allows the use of the R-23T and R-24T missiles, Kh-31A air-to-ship missiles, as well as the KAB-500Kr aerial guided bombs, unguided rockets, gun armament and unguided aerial bombs.
Equipping the aircraft with the Moskit-23 multifunction radar makes it possible to markedly enhance aircraft combat efficiency, first of all, due to:
- increasing the aerial target detection range up to 90 km;
- using the mapping mode to employ the Kh-31A antiship active-homing missiles (with an effective range of up to 100 km against sea targets) and the KAB-500Kr guided aerial bombs.

Second Version On retention of the Sapfir-23 airborne radar, the Moskit- 21K airborne radar is additionally pod-mounted, which does not require equipment rearrangement of the MiG- 23, MiG-23BN and MiG-27 aircraft. Much like the Moskit-23 radar, Moskit-21K is interfaced with the same armament.

Equipping the aircraft with the Moskit-21K multifunction radar makes it possible to enhance aircraft combat efficiency due to:
- increasing the aerial target detection range up to 50 km and using new air-to-air missiles RVV-AE, R-27R(T) and R-73;
- using the mapping mode to employ the Kh-31A antiship active-homing missiles (with an effective range of up to 50 km against sea targets), KAB-500Kr guided aerial bombs, unguided rockets, gun armament and unguided aerial bombs.

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://warfare.ru/?linkid=2420&catid=334

Airborne Radar Approaches

When an instrument pilot talks about a "radar approach" he usually means one that's guided by a ground controller using ASR or PAR equipment. But believe it or not, military aircrews have been known to make instrument approaches using their aircraft radar to find the runway. The author made hundreds of these approaches during his military flying career. But don't try this at home, kids...it takes top-notch radar and a lot of practice.

September 9, 1996

Many civilian pilots are aware, generally at least, of ground radars being used to guide airplanes to landings through the clouds. The military has used ground control approach (GCA) systems for many years. By the end of WWII and during the Korean War this was an established way of helping pilots. Radar systems housed in trailers could be relocated to different airfields, giving the military a world-wide capability despite the vagaries of weather.
The development of radar systems with precise target-tracking capabilities made GCA techniques possible. Those systems permitted trained radar-scope interpreters to guide planes down the glide path toward the runway. Accuracies to within a few feet in azimuth, elevation and distance (range) to the plane's radar echo made it possible to track and guide it to a safe landing.

When all else fails...

But what about airfields without GCA systems? Or when GCA systems are inoperative? Is there a backup? The answer is "that depends". It depends on two key factors. First, is the airplane equipped with its own precision radar system? And just as important, is there anybody aboard who is capable of accurately guiding the plane to a safe landing? In the early days, neither capability existed, despite the ego-based claims of radar manufacturers and some radar operators who felt they were the "world's greatest".

While the GCA operator looks for the radar echo of the incoming airplane, an airborne radar operator must find the end of the runway. Because airborne radar signals striking the runway tend to bounce off and away from the pavement, like a flashlight beam reflected off a mirror, the runway's appearance on the scope is dark, not a bright dot like the GCA view of a plane. The airborne operator searches for dark lines and patterns within the clutter of reflecting ground echoes. This can be tough in some situations. Not all military radar navigators and bombardiers could master the airborne radar directed approach (RDA).

The accuracy and precision required for an airborne radar directed approach is similar to that demanded for ground-based GCA systems. But it's a tougher job to reliably locate and track the end of the runway from a moving, bouncing airplane in the weather.

Will this work in my plane?

Could a pilot of a single engine or twin aircraft equipped with a weather avoidance radar make his own radar approach? Is the radar good enough? And what are the techniques needed to make such an approach?

Theoretically, the answer is a qualified "yes". But in a practical sense the answer is "probably not". Consider the following factors bearing upon airborne radar directed approaches. Then compare these against your weather radar's features.

1. 
   
   Your radar equipment must present a high resolution image, an accurate portrayal of the topographical and man-made features in and around the airport. That calls for a narrow radar beam (width under two degrees ) to preclude azimuth smearing of the images which could obscure the runway.
2. 
   
   The radar display should include accurate range markers or a variable calibrated cursor capable of indicating distances from the airplane to the end of the runway. It is critical that range is accurately determined to one-quarter mile or less.
3. 
   
   Short pulse lengths are also necessary to minimize range measurement errors. And it is useful to have adjustable gain and contrast controls to optimize the image for sharpness and maximum detail. Adjustable antenna tilt is not important because a narrow azimuth beam pattern often means a wide vertical pattern anyway. Remember, the target (runway) is not a radar blip. It's the absense of one within the clutter of ground returns and man-made objects.
4. 
   
   Simple weather radars typically display slant range and not ground range to the runway. There is a difference. Remember, you're flying down the glide slope along the hypotenuse of a right triangle, one side being your altitude and the other the ground distance to the runway. If your glide slope is steep the difference between slant range and ground range is greater than if the glideslope is shallow.
5. 
   
   The general procedure requires the pilot to know his ground range to the end of the runway as well as the heading to steer. At various ranges along the glidepath altitude and speed must be carefully maintained. Assume, for example, that groundspeed is 120 knots and a descent rate of 500 feet per minute is practical for your airplane and airfield obstacles. At five miles from touchdown you must be at 1250 feet AGL and on course. Touchdown is just 2.5 minutes away. At three miles out you must be at 750 feet and at one mile 250 feet AGL. All the while you must keep on course, aligned with the runway.
6. 
   
   As the range to the runway diminishes the radar image of the runway widens and smears. Close-in ground clutter brightens because echoes get stronger. You may detect the edges of the runway, the rough surfaces which reflect back toward you. The smooth runway itself will remain dark because returned echoes are absent.

Tougher than it sounds

It's a lot of work to fly the airplane precisely, maintaining course and glideslope while holding speed constant. Altitude at each range mark is crucial. There's no opportunity for one pilot to do all this while constantly monitoring the ever-changing radar images. It takes two people, a skilled radar operator and a capable pilot.

What weather minimums should apply to this technique? In the above example a 500 foot ceiling gives the pilot just one minute to transition to a visual approach and landing. At lower ceilings the time gets much shorter and there's not enough time to make last minute corrections. You're down to just seconds.

Equipment in many military bombers and fighters is accurate enough to make such approaches possible. Crews must practice to master the techniques and to perfect the coordination required.

Should others with less capable radar systems or no RDA experience try this? Even in an emergency situation? Not really. That's what alternate airfields are for.

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://www.avweb.com/news/system/183199-1.html

Airborne Radar: Military Systems Redesigned For Commercial Applications

The commercial market for ground-surveillance aircraft equipped with side-looking radar has been a tough nut to crack for U.S. defense contractors seeking to make international sales, said industry experts. The reasons for the slow business, sources said, are the high costs and a lack of understanding of the benefits of this technology.
Airborne radar includes three major categories: air-target surveillance and cueing radars mounted in rotodomes, nose-mounted fighter radars and side-looking radars for ground reconnaissance and surveillance. The latter is the smallest sector of the airborne radar market and is dominated by SAR (synthetic aperture radar) and GMTI (ground moving target indicator) sensors.
SAR, an active all-weather sensor, primarily is used for two-dimensional ground mapping. Radar images of an area help detect fixed targets. GMTI radar picks up moving targets or vehicles.
Raytheon Co., a leading U.S. airborne radar provider for the U.S. military, has had a tough time selling its commercial SAR-GMTI technology internationally, to civilian customers, said David Rockwell, senior analyst at the Teal Group, a business intelligence firm in Fairfax, Va. Raytheon makes several imaging and surveillance radar systems for U.S. military platforms, such as the radar for the U-2 spy plane and the APS-137 maritime surveillance radar for the U.S. Navy's P-3 aircraft.
In recent years, it began marketing a commercial version of its SAR-GMTI, called HiSAR, an X-band radar that can see from about 60 miles away. The company also is marketing a commercial derivative of the APS-137, called the SeaVue. SeaVue is sold to Australia, the United Kingdom, Japan and Italy.
The target customers for HiSAR, said Raytheon officials, are governments or commercial organizations with a budget of between $10 million and $30 million, for each system. Applications for airborne SAR-GMTI include detection of oil spills in the ocean, ice movement, changes in deforestation patterns, border surveillance and maritime patrol.
The HiSAR technology is about 10 years old, but Raytheon only started marketing it internationally four years ago. "Sales have not been huge," said Rockwell. "The market is moving along at a slow rate. It's been questionable for several years. [Raytheon] could make some major sales but they haven't yet." The company inherited the HiSAR technology from Hughes Corp., which was acquired by Raytheon.
It has been hard for the international non-U.S. markets to accept SAR, said Jorge L. Ramirez Jr., manager of business development at Raytheon Electronic Systems.
The reasons, he said, are "costs and lack of understanding." The technology has been around for 50 years and still, "many don't understand the benefits of SAR-MTI technology," Ramirez said. Unlike photographs or video, SAR images are not intuitive, meaning that only trained operators can understand them and interpret them.
According to Rockwell, the obvious target market for airborne SAR-GMTI is military customers, rather than civilians. In the military sector, Joint STARS is "the 800-pound gorilla" among airborne SAR systems. Joint STARS is a U.S. Air Force high-performance ground surveillance system mounted on a Boeing 707 jet. The prime contractor is Northrop Grumman Corp.
The Teal Group estimated that annual sales of airborne SAR systems worldwide will remain steady at about $600 million.
"Whether HiSAR will develop a commercial market is a bigger question," said Rockwell. "There is certainly a military market."
HiSAR has been installed in the U.S. Army's RC-7B reconnaissance aircraft and the Beech King Air. A HiSAR derivative was developed for the Air Force Global Hawk UAV.
According to Raytheon officials, HiSAR is much less sophisticated than the $300 million Astor aerial surveillance system that the company is developing for the United Kingdom, under a $1.2 billion contract. Astor has a much higher resolution and other advanced features, which are classified.
In the global market for SAR, there is no dominant prime today, said Rockwell. He is not sure which company would be in a position to take that role. Raytheon faces tough competition from European and Israeli firms. In the United States, it competes against Telephonics Corp. for military airborne SAR business. Telephonics' future market share of airborne SAR largely is tied to the U.S. Navy's SH-60R helicopter. If the Navy does not buy as many helicopters as planned, "then Telephonics is not very well placed to rival Raytheon," said Rockwell.
A Telephonics spokesman said the company does not plan to develop commercial SAR-GMTI systems for international sales.
Northrop Grumman's role in airborne SAR is limited to Joint STARS, for the most part, said Rockwell. NATO is considering buying a new airborne ground-surveillance aircraft. One of the bids for that system includes a radar jointly developed by Northrop Grumman and Raytheon.
During the 2001 Paris Air Show, Raytheon marketed the HiSAR on two fronts. It kicked off the so-called HiSAR Institute, a seminar designed to teach potential customers about the benefits of SAR-GMTI. And it also introduced a HiSAR 2K system, which has longer range and higher resolution than the baseline system.
Justin C. Monger, manager of business development at Raytheon, said the company estimated that there is an international HiSAR market worth about $1 billion over five years, not including platforms. "Half our customers have their own platforms. We also provide used platforms," said Monger.
Last year, he said, Raytheon sold 10 systems, worth about $200 million, to international customers. "They were commercial sales, but we are not allowed to reveal the buyers or they threatened to cancel the contracts." In today's market, he said, 10 systems is a huge number.
"I agree with Raytheon that there should be a market for this technology," said Rockwell. "But it hasn't really panned out in the last five years. It could still be there, but they may not make it for five or 10 years." HiSAR is a pricey system, he said.
"Even at $10 million-$30 million, these systems are still too expensive for commercial users," he said.
For $11 million, Monger said, his company can provide the radar, the airplane, a ground station, training, spares and a logistics package. "That is how we are going to break into the market," he said.
The HiSAR 2K system has as 1-meter image resolution, which is detailed enough to be able to classify vehicles on the ground, Monger said. The baseline HiSAR resolution is 6 meters.
A SAR image of oil tanks in the ocean, for example, can be used to determine whether oil supplies are decreasing over time.
A HiSAR 2K radar can operate in two different modes. At 1-meter resolution, it has a range of more than 120 miles, but can only cover a narrow field of view. At a coarser resolution—8 meters—it can cover a broader area, about 35 miles wide.
For border surveillance, a SAR aircraft typically would fly at an altitude of 25,000-30,000 feet and from about 40 miles away.
It took several years to develop HiSAR 2K, said Monger. "We steal from other programs within Raytheon." In the future, he said, "We have new modes coming out that we have not announced yet, because they are not ready."
The system has an 80 percent probability of detection. Targets are not detectable when they are positioned parallel to the radar, Monger explained. "You need to line up your mission plan, so you are not parallel to your roads."
Improving the performance beyond 80 percent is not an option for Raytheon at this time, because the technology to do that is not licensed for non-U.S. sales, he said.
For other surveillance applications, radar can be mounted on aerostats, said Monger. "We believe that there is a market for aerostat systems," he said. For missions such as early warning, which requires around-the-clock surveillance, aerostats are suitable platforms, he added. The caveat, however, is that aerostats only should operate in a "low threat environment" and in areas where the winds don't exceed 100 knots. "It's a niche within the surveillance market," said Monger. There are 12 aerostat systems along the U.S. Southern border (between New Mexico and Florida) watching airborne drug runners coming in from the South, he noted.
Raytheon built an early-warning aerostat, funded by the U.S. Army, for cruise-missile defense. The aerostat is tethered to the ground. A fiber optic link sends the data down to the ground station for processing. The company is working on a mobile mooring ground station, on wheels, for possible military use.

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://www.nationaldefensemagazine.org/ARCHIVE/2001/AUGUST/Pages/Airborne_Radar6969.aspx

Arctic Trek to 'Break the Ice' on New NASA Airborne Radars

April 30, 2009 PASADENA, Calif. – NASA will 'break the ice' on a pair of new airborne radars that can help monitor climate change when a team of scientists embarks this week on a two-month expedition to the vast, frigid terrain of Greenland and Iceland.



Scientists from NASA's Jet Propulsion Laboratory, Pasadena, Calif., and Dryden Flight Research Center, Edwards, Calif., will depart Dryden Friday, May 1, on a modified NASA Gulfstream III aircraft. In a pod beneath the aircraft's fuselage will be two JPL-developed radars that are flying test beds for evaluating tools and technologies for future space-based radars.



One of the radars, the L-band wavelength Uninhabited Aerial Vehicle Synthetic Aperture Radar, or UAVSAR, calibrates and supplements satellite data; the other is a proof-of-concept Ka-band wavelength radar called the Glacier and Land Ice Surface Topography Interferometer, or GLISTIN.



Both radars use pulses of microwave energy to produce images of Earth's surface topography and the deformations in it. UAVSAR detects and measures the flow of glaciers and ice sheets, as well as subtle changes caused by earthquakes, volcanoes, landslides and other dynamic phenomena. GLISTIN will create high-resolution maps of ice surface topography, key to understanding the stresses that drive changes in glacial regions.



During this expedition, UAVSAR will study the flow of Greenland's and Iceland's glaciers and ice streams, while GLISTIN will map Greenland's icy surface topography. About 250,000 square kilometers (97,000 square miles) of land will be mapped during 110 hours of data collection.



"We hope to better characterize how Arctic ice is changing and how climate change is affecting the Arctic, while gathering data that will be useful for designing future radar satellites," said UAVSAR Principal Investigator Scott Hensley of JPL.



The Gulfstream III flies at an altitude of 12,500 meters (41,000 feet) as UAVSAR collects data over areas of interest. The aircraft then flies over the same areas again, minutes to months later, using precision navigation to fly within 4.6 meters (15 feet) of its original flight path. By comparing the data from multiple passes, scientists can detect very subtle changes in Earth's surface.



L-band Principal Investigator Howard Zebker of Stanford University, Palo Alto, Calif., and his team will use UAVSAR to collect data on various types of ice. They will measure how deeply the L-band radar penetrates the ice and compare it with similar C- and X-band radar data collected from satellites. Scientists expect the longer wavelengths of the L-band radar to penetrate deeper into the ice than C-band radar, "seeing" ice motions or structures hundreds of meters below the ice surface, rather than only at the surface. By using both wavelengths, scientists hope to obtain a more complete picture of how glaciers and ice streams flow. Zebker's team will also evaluate how sensitive the L-band radar is to changes in the ice surface between observations.



To better predict how glaciers and ice sheets will evolve, scientists need to know what they're doing now, how fast they're changing, what processes drive the changes and how to represent them in models. Accurate measurements of ice sheet elevation derived from laser altimeters (lidars) on aircraft or satellites are critical to these efforts. But high-frequency microwave radars can also do the job, with greater coverage and the ability to operate in a wider range of weather conditions. Until now, however, microwave radars operating at wavelengths longer than those of GLISTIN have penetrated snow and ice more deeply than lidars, making interpretation of their data more complex.



Enter GLISTIN, the first demonstration of millimeter-wave interferometry, which was developed to support International Polar Year studies. Principal Investigator Delwyn Moller of Remote Sensing Solutions, Barnstable, Mass., and her team will evaluate GLISTIN's ability to map ice surface topography. GLISTIN has two receiving antennas, separated by about 25 centimeters (10 inches). This gives it stereoscopic vision and the ability to simultaneously generate both imagery and topographic maps. The topographic maps are accurate to within 10 centimeters (4 inches) of elevation on scales comparable to the ground footprint of a lidar on a satellite.



Scientists expect GLISTIN to penetrate the snow and ice by just centimeters, rather than by meters, as current microwave radars do. A multi-institutional team will conduct coordinated lidar and ground measurements to help quantify how deeply GLISTIN's Ka-band radar penetrates the snow and ice and to verify model predictions.



GLISTIN data will aid in designing future Earth ice topography missions and even missions to map ice on other celestial bodies. Scientists will also apply its data to designing missions to map Earth's surface water and ocean topography.



A joint partnership of JPL and Dryden, UAVSAR evolved from JPL's airborne synthetic aperture radar (AIRSAR) system that flew on NASA's DC-8 aircraft in the 1990s. In 2004, NASA's Earth Science Technology Office funded development of a more compact version of AIRSAR to be flown on uninhabited aerial vehicles. UAVSAR made its first operational flight in November 2008. JPL is managed for NASA by the California Institute of Technology in Pasadena.

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://www.jpl.nasa.gov/news/news.cfm?release=2009-075

the Model ASB radar

Prior to America's entry into World War II and in anticipation of the German submarine menace, NRL developed the Model ASB radar. It was the first operational U.S. airborne radar to be widely used for bombing, detection of ships and surfaced submarines, and airborne intercept. This radar saw extensive use during the war, not just by the U.S. Navy and Army Air Forces, but also by the British. It was installed almost universally in U.S. naval aircraft and became known as the "Workhorse of Naval Aviation." The Model ASB was the first radar to be used in carrier-based aircraft and was effective in attacking and destroying Japanese ship convoys in the Pacific. It was also effective against Japanese aircraft. It has been said that the ASB "was one of the most successful of all airborne surface search radars."

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://www.nrl.navy.mil/content.php?P=AIRBORNRADAR

Airborne Radar That Tracks Missiles

Two giants in the airborne radar field have joined to develop a new radar that can detect and track, not only ground targets and aircraft, but also cruise missiles. It's a unique system designed by a unique partnership.

James W. Ramsey

Existing airborne radars can detect and track moving ground vehicles and aircraft. Now the U.S. Air Force is developing the first airborne surveillance radar capable of detecting and tracking low-flying cruise missiles. And despite budget uncertainties, the development program is on schedule.

Two leading U.S. radar providers, Northrop Grumman and Raytheon, are teamed in a unique partnership to develop the new sensor in the Multi-Platform Radar Technology Insertion Program (MP-RTIP). Northrop Grumman is the prime contractor, but it splits development and initial production work on the new radar system 50-50 with Raytheon. This arrangement to develop the radar for the new E-10A wide-area surveillance (WAS) aircraft and the Northrop Grumman Global Hawk unmanned air vehicle (UAV) seems to be working. "The program is progressing well," declares Col. Joseph Smyth, commander of the E-10/MP-RTIP systems group at the USAF's Electronic Systems Center.

The radar program successfully completed its final design review in June 2004, and a laboratory-based prototype system was tested at Raytheon's El Segundo, Calif., facility last September.

Following the award of a six-year, $888-million contract for the program's system development and demonstration (SDD) phase, the companies have been procuring components and preparing to build the first flyable system, scheduled to be tested on a Global Hawk surrogate aircraft in October 2006. At the same time a larger version of the modular scalable radar will be produced for test flight on a Boeing 767-400ER test bed, the anticipated aircraft platform of choice for the E-10A program.

Comparison to JSTARS

Both contractors and the service claim that the new radar will enhance the USAF's ability to track and identify stationary and moving vehicles, as well as hard-to-detect cruise missiles. It also will perform battlefield command and control functions.

Unlike currently fielded airborne systems, such as the E-8C Joint Surveillance Attack Radar System (JSTARS), the MP-RTIP radar will be able to collect ground moving target indicator (GMTI) imagery and synthetic aperture radar (SAR) still images nearly simultaneously. The radar also will be able to detect, track and identify more targets faster and with higher resolution than ever before, according to Dave Mazur, MP-RTIP program manager at Northrop Grumman's Integrated Systems sector in El Segundo.

"The key difference in this radar over the JSTARS radar is the fact that it includes missile defense. That capability doesn't exist today in an airborne platform," says Mazur. "And this radar, in comparison, offers increased range, accuracy and resolution, and faster revisit time."

The Air Force concurs. "The MP-RTIP being designed for the E-10A will provide five to 10 times the air-to-ground surveillance capability of JSTARS," Col. Smyth adds. What assures this capability is the new radar's larger aperture, the increased available power to the system, and its active electronically scanned array (AESA) antenna, which automatically scans in both azimuth and elevation," Mazur explains. "That means we can almost instantly revisit several areas at one time. Each pulse can be doing a different technique."

"Not only can you run [software] modes in sequence, you can interleave them," adds Tom Bradley, Raytheon's MP-RTIP program manager. He explains that, with one asset tasked to carry out significantly different missions, the platform will be able to collect and integrate "all types of intelligence on ground moving targets, imagery and low-flying threats," and provide the user with a comprehensive threat picture.

Both contractors bring considerable AESA antenna experience to the table. Northrop Grumman has developed radar systems for the new F-22 and F-35 fighters, while Raytheon is providing similar radars for the F-15 and F/A-18E/Fs. (The first operational unit equipped with Raytheon's AESA radars is an F-15 squadron based in Alaska). Raytheon also is upgrading the active array radar for Northrop Grumman's B-2 bomber program.

While not planned to replace the E-3A Airborne Warning and Control System (AWACS) radar, MP-RTIP can track conventional aircraft as well as cruise missiles. "The frequency we operate at--X-band--is different from [that used by] AWACS," says Mazur. (The Air Force's AWACS uses S-band radar.) "This allows us to have a very narrow beam, which allows [the radar] to be very accurate. We need that to track cruise missiles. This is a feature we can exploit to augment the AWACS capability."

An AESA includes thousands of transmit and receive modules that are assembled onto "subarrays" inserted into the antenna. The antenna then sends the radio frequency (RF) signals to a receiver, and the radar support electronics processes them.

While the antenna remains stationary, the beam is steered electronically. And the radar's electronic scanning capability moves the beam much more rapidly than previous systems, promoting improved radar searching and multiple tracking capabilities. By removing gimbals and other moving parts associated with manually scanned antennas, AESA offers increased reliability, Raytheon and Northrop claim.

Radar Size

The MP-RTIP radar being developed for the E-10A is a side-looking radar, whose antenna aperture units and associated avionics are mounted in a pod underneath the fuselage, forward of the wing root. While the antenna doesn't move in azimuth or elevation, it does rotate on gimbals 180 degrees to look out the other side of the aircraft.

The radar antenna for the Global Hawk measures 1.5 feet (0.46 m) tall by 5 feet (1.5 m) long. On the E-10A the antenna is considerably larger: 4 feet (1.2 m) tall by 20 feet (6.1 m) long. (The JSTARS pod measures 2 by 24 feet [0.6 by 7.3 m]).

The MP-RTIP requires a widebody aircraft such as the B767, primarily because of the radar's height. "You need something with a big enough landing gear, to account for a hard landing with all tires blown, and you are riding on the rims, and your shocks are fully compressed," Mazur explains. "You must have adequate clearance, so you don't go in there and scrape off the radar."

Most of the electronic equipment supporting the radar--including receivers/exciters, power conditioning units and processors--are mounted inside the E-10A's cargo bay. A separate (helicopter) jet engine, mounted in the cargo bay in a fireproof enclosure, powers the radar.

In terms of radar hardware, Global Hawk bears a "two box" system, with the antenna mounted below the aircraft and the signal processor inside an avionics bay. The radar mode software resides in the signal processor, which is responsible for controlling the radar, running it and processing the data.

Scalable Radar

The USAF's original intent was to make MP-RTIP a radar upgrade for JSTARS--the service's airborne ground surveillance, targeting and battle management system--which has been used effectively in the Iraq war. But MP-RTIP evolved into an advanced system that a widebody platform could best accommodate. (JSTARS uses the narrowbody Boeing 707.)

MP-RTIP was designed to be a scalable radar, using the same basic architecture and common software, but with a smaller aperture to accommodate later model Global Hawks. (A scenario is envisioned using both the Global Hawk and E-10A together for battlefield surveillance and air-to-air detection.)

Teaming Arrangement

Northrop Grumman Integrated Systems is the prime contractor for MP-RTIP, although its program management, modeling and simulation, and Global Hawk flight test activities account for only about 10 percent of the program. The other 90 percent involves the radar's design, development and testing. These activities are split evenly between Raytheon's Space and Airborne Systems unit in El Segundo and Northrop Grumman's Electronics Systems sector in Baltimore and Norwalk, Conn. All work on MP-RTIP falls under Mazur's realm of responsibility.

"Northrop Grumman and Raytheon are fierce competitors in the radar world, so bringing these two teams together to work on this program smoothly has been a challenge. But we've been very successful at it," boasts Mazur. (In fact, the Air Force granted the two contractors 100 percent of incentive award fees for successful teamwork in the contract's first phase.)

As for hardware, Raytheon is providing the MP-RTIP's "front-end" RF aperture unit (RFAU) antenna assemblies on the E-10A, while Northrop Grumman Electronic Systems provides the radar back-end. "We build the aperture assemblies into an antenna and provide receivers/exciters, cabinets and a radar signal processor," says Russ Conklin, MP-RTIP program manager for Northrop Grumman Electronic Systems. Northrop Grumman is responsible for the E-10A's radar integration and testing at its systems integration laboratory in a former Norden facility in Connecticut.

On Global Hawk the contractors' roles are reversed. Northrop Grumman builds the antenna elements and Raytheon, the back-end. Raytheon is responsible for integration and testing at its systems integration lab in El Segundo. There the software modes are added prior to flight test--and for testing on the Global Hawk.

"We at Raytheon build the currently used Global Hawk radar sensor, which has SAR and MTI [moving target indicator] modes, and we have a lot of experience putting it out in the field," says Raytheon's Bradley. "Northrop Grumman is doing Joint STARS and brings that system experience forward."

"Global Hawk is reconnaissance, and Joint STARS is really surveillance," he adds. "Now you're creating a platform that can do both. And by adding some air-to-air mode support, it also is going to be doing cruise missile defense."

The basic MP-RTIP software on the E-10A and Global Hawk are common. Both Raytheon and Northrop Grumman, together, are writing the radar operating services (ROS), built-in test (BIT) and calibration. One team member or the other is writing independently each of the three major radar modes: GMTI, SAR and airborne moving target indicator (AMTI).

Fitting MP-RTIP on Global Hawk is a plus for the E-10A program, Mazur says, because a number of the MP-RTIP modes are common between the two platforms. "We can do a lot of the integration and testing and validation before we get to the E-10A platform, so it helps us save test time on the E-10A portion. It is more expensive to run a B767 than to fly a Global Hawk."

Raytheon also brings its transmit/receive (TR) module manufacturing capability to the program. "We have a dedicated factory down in Texas [attained when Raytheon acquired Texas Instruments in Dallas]," Bradley points out.

Both Raytheon and Northrop Grumman Electronic Systems work closely with Mercury Computer Systems, a commercial off-the-shelf (COTS) vendor in Chelmsford, Mass., that provides processors for radar signal processing and the receiver/exciter hardware.

Program Status

The MP-RTIP program was officially launched with a phase 1, three-year $415-million contract awarded to the team in December 2000. With a positive cost performance, the team "under-ran" the contract and continued to work on it into February of 2005, according to Mazur. In July 2003 the radar's integrated targeting capabilities were demonstrated in a series of virtual war games hosted on Northrop Grumman's cyber warfare integration network (CWIN), a nationwide virtual battlefield environment.

"We demonstrated that by using three coordinated MP-RTIP wide-area surveillance aircraft dispersed over a large geographic region, a commander could simultaneously defend against cruise missiles fired from multiple locations and conduct a precision strike against a column of enemy armored vehicles," says Mazur.

In late 2004, after the final design review authorized the Northrop Grumman team to begin building and testing the new radar, the team integrated and tested a laboratory-based prototype of the MP-RTIP radar at Raytheon's California facility. As part of a risk reduction program, off-the-shelf equipment was used to build a Global Hawk radar for initial testing to resolve technical issues well in advance of the production and integration of actual flight hardware.

Originally envisioned as a "single string" radar, with only one RF aperture unit and the avionics to support it, MP-RTIP "eventually morphed into a full set of four RFAUs, which is basically what the Global Hawk radar will look like," says Mazur. "In demonstrating this software, we did two air-to-air modes with this prototype radar, using a target generator [in a Raytheon facility] a couple of miles away. That [radar] is going to be taken now and modified into one of the three radars to be delivered for Global Hawk. This one will not fly, but stay in the lab."

Proteus Test

Following build-up of the equipment and software modes for the Global Hawk system, flight tests of the radar are scheduled to start in October 2006. The Northrop-Raytheon team will use the Proteus surrogate, a manned high-altitude, long-endurance aircraft built by Scaled Composites. The radar will be pod-mounted and monitored by a flight engineer on flights near Edwards AFB, Calif. The schedule calls for one flight a week, after which the radar will be integrated into a Global Hawk vehicle for further testing.

Proteus flies at the same altitude as Global Hawk and is more efficient to use than the manned platform for initial tests, Mazur explains. The two-seat Proteus will "drastically reduce the amount of time we have to test on Global Hawk." Also, having a man in the loop allows for more efficient testing, he adds.

With flight test of the MP-RTIP radar less than two years away, "we are well into actual development of the Global Hawk radar, buying material, including processors and computers, having released all the drawings, and putting together plans that say how to actually build the radar," says Mazur. Software design is complete, but coding and testing continues.

On the E-10A radar, the team is in the initial stage of buying material. It expects to flight test the MP-RTIP on the E-10A in two to three years after the Global Hawk tests begin next year.

'Umbrella' Program for E-10A

Northrop Grumman's Airborne Ground Surveillance and Battle Management Systems, a business unit of Integrated Systems in Melbourne, Fla., is handling the E-10A weapons systems integration (WSI) program, as well as the battle management command and control (BMC2) program, awarded last September.

E-10A WSI, awarded in May 2003, is an umbrella program that uses a "green" commercial test bed aircraft--in this case a Boeing 767-400ER. (Contract negotiations between the U.S. Air Force and Boeing were completed last September.) WSI calls for integrating the MP-RTIP radar and BMC2 system into one aircraft.

The BM2C contract, which includes all the aircraft "back-end" equipment and software required to communicate with and relay sensor information to ground commanders or other aircraft, also was awarded to Northrop Grumman last September in a major competition against teams headed by Lockheed Martin and Boeing. Since Northrop Grumman already had won the E-10A WSI program, BM2C was folded into that contract.

"We take the aircraft, the radar and the battle management `C and C' [command and control], which is basically everything from the cockpit back--the three major subsystems under WSI--and integrate those," explains Jerry Madigan, vice president of the E-10A program for Northrop Grumman. "We do all the systems engineering work to enable the weapons system to meet the user requirements."

Aircraft modification work on the B767-400 will be done at Northrop Grumman's Lake Charles, La., facility. The aircraft then will be taken to Melbourne for installation of all prime mission equipment, including the radar, computers and communications equipment, leading to flight test there.

Northrop Grumman has subcontracts with Boeing to support the commercial aircraft and with Raytheon for liquid cooling of the radar installation. Northrop Grumman handles equipment installation in the main cabin, as well as electrical power and cooling distribution for those devices. The company also is letting subcontracts for radios and computers, and has signed up a dozen subcontractors. These subs include: General Dynamics (multilevel security), Harris Corp. (communications), L-3 Communications, Alphatech and Zeltech (target tracking), Oracle (commercial databases), Telephonics (intercom system) and All Points (a disabled veterans' company that provides Sun Microsystems equipment and engineering). Other Northrop Grumman units, including Mission Systems in Reston, Va., are involved in the program.

A systems requirements review was complete on the E-10A program last December. It incorporated BMC2 requirements that baselined the program. The initial design review is planned for next October, although budget cuts may cause the program to be restructured, with some schedule changes to occur, says Madigan. The Defense Acquisition Board planned to hold a Milestone B program review of the E-10A system in March 2005.

Northrop Grumman's E-10A program personnel also will be involved in the upcoming radar tests on the Proteus surrogate. "There is a common set of modes that go on E-10A and on Global Hawk, so in a lot of ways, that testing is risk reduction for our program," says Madigan. "We're looking forward to that test."

While the new MP-RTIP radar development has proceeded through its final design review on schedule, the fate of the integration of the E-10A program and its accompanying command and control system--contracts won by Northrop Grumman--is literally up in the air. The program, reportedly initially funded at $5.3 billion, has taken budget cuts in FY2003 and FY2005. The USAF, under current funding, has restructured the program to demonstrate the MP-RTIP radar capabilities and E-10A key performance parameters before entering the E-10A SDD phase. The service's FY2006 request sent to Congress in February calls for $397 million for the E-10A program.

The plan still calls for the production of one test bed 767-400 and four production E-10As although a formal decision on the aircraft platform is pending a program milestone review. The deployment of the production aircraft has slipped from the 2015 to the 2017 time frame.

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://www.aviationtoday.com/av/categories/military/828.html

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EADS And Northrop Grumman Announce Cooperation On Airborne Radar Systems

Le Bourget, 20 June 2001

EADS European Aeronautic Defence and Space Company and Northrop Grumman Corporation (NYSE: NOC) have entered into a Memorandum of Understanding (MoU) with the objective of bringing together their technological skills in the field of airborne radar.

As both companies announced on Wednesday at the Paris Air Show in Le Bourget, Northrop Grumman's Overseas Service Corporation and EADS' Systems and Defence Electronics (S&DE;) business unit have signed this MoU to consider the exploitation of their collective technical and business strengths in pursuit of a common radar solution for U.S. transport aircraft. The aim is to enhance the safety of aircraft operation independent from weather and daylight conditions, particularly during landing and taxiing, by establishing an Enhanced Vision System. The project will be based on Northrop Grumman's APN-241 aerial delivery radar and EADS' HiVision sensor technology.

"We look forward to working closely with EADS to develop a collaborative business activity intended to market and support the EADS HiVision millimeter wave radar sensor," said Bob DuBeau, Vice President of Northrop Grumman's Avionics Systems business unit.

The HiVision radar contains a frequency-modulated, continuous wave radar sensor operating in the millimeter wave band. It is a short-range sensor for navigation (landing aid), runway detection and collision warning up to a distance of five kilometers. Under the proposed collaboration, Northrop Grumman will be responsible for adaptation, production and support of the HiVision radar sensor for the U.S. transport aircraft programs.

"The increase in modern traffic, the demand for economic operation and more stringent safety demands require the weather and daylight-independent operation of aircraft," said Johann Heitzmann, Head of EADS Airborne Systems. "And this requirement is met by imaging sensor support, which can be offered in a very cost-effective way by bringing together the existing concepts and comprehensive proficiency of our companies in this field."

The activity covered by this latest MoU is a further expansion of the existing cooperation of EADS and Northrop Grumman as displayed in a shared pavilion at Le Bourget. A general memorandum of understanding signed by the two companies in April 2000 started the evaluation of various activities in the C4ISR sector.

EADS has arisen from the merger of Aerospatiale Matra, Construcciones Aeronauticas S. A. and DaimlerChrysler Aerospace AG. With revenues of Euro 24.2 billion (2000) and 100,000 employees, EADS is the third largest aerospace company in the world. EADS has valuable capabilities and experiences in the field of enhanced ISR sensor systems, avionics and subsystems design as well as command, control, communications, computers and intelligence.

Northrop Grumman Corporation is a $15 billion, global aerospace and defense company with its worldwide headquarters in Los Angeles. Northrop Grumman provides technologically advanced, innovative products, services and solutions in defense and commercial electronics, systems integration, information technology and non-nuclear shipbuilding and systems. With 80,000 employees and operations in 44 states and 25 countries, Northrop Grumman serves U.S. and international military, government and commercial customers.

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://www.eads.net/1024/es/pressdb/archiv/2001/es_lb_dcs_sysde_hivi.html

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Next-generation airborne radar demands powerful computers

The radar on the Air Force Global Hawk UAV will track cars and missiles with a powerful onboard computer from Mercury Computer Systems. CHELMSFORD, Mass. - When Air Force pilots steer the E-10A Joint Surveillance Target Arrack Radar System (Joint STARS) surveillance airplane near battlefields sometime after 2013, its powerful radar will track evasive cars and wagons through city streets, and simultaneously track low-flying cruise missiles.

That radar is called the Multi-Platform Radar Technology Insertion Program (MP-RTIP), and it relies on massive onboard computers.

Raytheon is building the active, electronically scanned array radar for its partner, Northrop Grumman. MP-RTIP is modular, so they will build a large version for the E-10A, a mid-sized version for NATO aircraft, and a small version for the Global Hawk unmanned aerial vehicle (UAV).

All the versions are powered by a crucial technology - powerful and efficient computers processing that data while it is being collected. Subcontractor Mercury Computer Systems of Chelmsford, Mass. is building the computers.

To handle the massive ­signal-processing load, Mercury engineers upgraded their Power­Stream Multi-Port 410 computer, now used on the Joint STARS. The result is the PowerStream 7000, about eight times more powerful than its predecessor.

The PowerStream 7000 is a cube the size of a hotel room mini-refrigerator, with four strong fans blowing hot air out the top. It contains 24 slots with five processors each, running 120 PowerPC 7447 chips connected through a passive backplane with RapidIO switched fabric. It gets I/O bandwidth from 32 PMC or XMC cards. Altogether, the unit creates 1 trillion floating-point operations per second (1 TeraFLOPS) of processing power.

Stuffed with microprocessors, bridge chips, switches, and memory devices, the computer is so dense that designers worried about dissipating the heat. They used an approach called "managed air," which forces cool air to flow through channels like water. With this method, PowerStream can cool 200 watts/slot.

"We make sure there's no air molecule that's wasted. We manage them as carefully as the electrons in the circuits," says Barry Isenstein, vice president and general manager of the company's Defense Electronics Group.

Cooling sounds boring but it is probably the number-one challenge restricting computer growth in general. Apple just released a liquid cooled chip, modeled after the way you cool your car." In fact, he says, cooling is now the biggest hurdle to Moore's Law, the dictum that engineers will find ways to double the number of gates on a processor every 18 months.

Density alone is not good enough for this job - the computer also has to be power-efficient. "It's all about efficiency, turning watts into flops. You only get the power that's left over from keeping the plane aloft," says Jonathan Schonfeld, Segment Manager for Radar in Mercury's Defense Electronics Group. FLOPS are floating point operations per second.

That is an even bigger challenge on smaller aircraft. While the full-size PowerStream 7000 rides on the E-10A's adopted Boeing 767, a small version also processes radar signals on the Global Hawk UAV.

Pentagon leaders protect those expensive assets with long standoff distance, using altitude for the Global Hawk and range for the MC2A. The drawback is that distance increases the signal-to-noise ratio in the radar data, making a harder computing task.

But electronics designers can't win, Isenstein says if those planes flew closer to the battlefield, they would need more defense systems, leaving less space and power for signal processing.

Across the industry, defense electronics makers face a similar set of technical challenges. "The industry is entering a period of dramatic change. The infrastructure that the meat of the market is using VME will have to change," Isenstein says.

Three trends are hitting the defense electronics industry at once. First, engineers are changing designs from the parallel database to serial fabrics. As the change hits mainstream design, even processor manufacturers are putting fabric technology directly on the chips.

Second, says Isenstein, "The venerable old VME connector can't do it; we need a new form factor." The challenge for designers is how to keep current hardware compatible with the next generation. "If you're a defense contractor launching a platform for 2006, you have to think long and hard about what to do. If you go with VME, you're planning for a forklift upgrade."

And third, chips are growing too hot. As standard processors get faster than ever, they also use more power. Some designers are using field programmable gate arrays instead of digital signal processors, but the challenge remains.

"All three factors are changing at once. That's a lot of uncertainty, compared to the incremental improvements we've seen in VME over the past 15 years," he says.

That is one reason that Mercury engineers changed from Race ++ to RapidIO when they upgraded the PowerStream 410. Both technologies are switched serial interconnects, but the new fabric provides more bandwidth per pipe, more pipes, and more efficient switching, says Isenstein.

Faced with the sheer number of pixels and moving targets on a modern battlefield, they needed to push the processors as fast as they could go. The E-10A will perform both surveillance and management of the battlefield, according to its full name, the Multi-sensor Command and Control Aircraft (MC2A).

"Joint STARS was looking at a small number of Soviet tanks, while today MC2A must keep track of every station wagon, every minivan, and every Mini Cooper. In the old days, missing one tank was not all that big a deal, but today you miss one missile launcher and that could blow up a city," says Schonfeld.

That task gets even harder in the modern urban battlefield, since radar traditionally has good resolution along the line of sight, but needs heavy signal processing to get fine resolution images perpendicular to the line of sight.

"The trouble with urban surveillance at fine grain is that buildings get in the way," Schonfeld says. And to add a final level of challenge, the mission of MC2A is to present that data as movies that show where the traffic is going, not just surveillance snapshots. Until the mid-1990s, designers couldn't even refresh a screen often enough to display that data.

In April 2004, Air Force leaders awarded $888 million to Northrop Grumman for Phase II of MP-RTIP. Northrop Grumman designers are creating the Battle Management Command and Control (BMC2) architecture to control all the data. And in June, Northrop Grumman gave $369 million of that grant to Raytheon to build the radar and produce six MP-RTIP radar systems - three each for the E-10A and for Global Hawk. The new radar will enable airmen to simultaneously collect ground moving target imagery and synthetic aperture radar signals. It will also offer an air moving-target indicator, used to track cruise missiles.

Military & Aerospace Electronics February, 2005
Author(s) :   Ben Ames

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://mae.pennnet.com/Articles/Article_Display.cfm?Section=Archives&Subsection=Display&ARTICLE_ID=222005

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Sci-Tech Encyclopedia: Airborne radar

Radar equipment carried by commercial and military aircraft. These aircraft use airborne radar systems to assist in weather assessment and navigation. Military systems also provide other specialized capabilities such as targeting of hostile aircraft for air-to-air combat, detection and tracking of moving ground targets, targeting of ground targets for bombing missions, and very accurate terrain measurements for assisting in low-altitude flights. Airborne radars are also used to map and monitor the Earth's surface for environmental and topological study.

Airborne radars present unique design challenges, mainly in the severe nature of the ground echo received by the radar and in the installation constraints on the size of the radar. The peculiar clutter situation governs the nature of the signal processing, and the installation limitations influence the antenna design and the radio frequency to be used (the two being strongly related) as well as the packaging of the rest of the radar. Similar considerations influence the design of space-based radars as well.

A particularly valuable use of airborne radar is weather assessment. Radars generally operating in the C or X bands (around 6 GHz or around 10 GHz, respectively) permit both penetration of heavy precipitation, required for determining the extent of thunderstorms, and sufficient reflection from less intense precipitation. See also Meteorological radar; Radar meteorology.

Another basic and valuable airborne radar function is altimetry. The aircraft's altitude can be continuously measured, using (generally) C-band frequencies (around 6 GHz), low-power transmission, and a downward-oriented antenna beam. Sometimes, information from additional beams (looking somewhat forward, for example) is combined with measurements of the Doppler shift of the ground echo received to further aid in navigation. Another type of radar used in navigation is the radar beacon, in which a ground-based receiver detects an interrogation pulse from the aircraft and sends back a so-called reply on a different frequency, to which the receiver on the aircraft is tuned. See also Air-traffic control; Altimeter; Doppler effect; Surveillance radar.

Airborne radars are used effectively to provide high-resolution mapping of Earth's (or other planetary) surface, with a technique called synthetic aperture radar (SAR). The processing uses the fact that surface objects produce a Doppler shift (due to the aircraft's flight) unique to their position as the aircraft passes by; this Doppler history is indicative of the scatterer's lateral, or cross-range, position at the particular range determined by the usual echo timing. With very stable radars and well-measured flight characteristics (and other focusing methods), picture cells (pixels) of 1 ft × 1 ft (0.3 m × 0.3 m) can be formed in the processed images from radars tens or hundreds of miles away. The resolution is somewhat like that possible had the flight path itself been used as a huge antenna, the synthetic aperture.

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://www.answers.com/topic/airborne-radar

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NASA Sends Airborne Radar to Map Haiti Faults in 3-D

NASA is sending a radar-equipped jet to Haiti to make 3-D maps of the deformation caused by the magnitude 7 earthquake on Jan. 21 and multiple aftershocks that continue to occur.

The Uninhabited Aerial Vehicle Synthetic Aperture Radar, or UAVSAR, was already scheduled to head to South America aboard a modified Gulfstream III to study volcanoes, forests and Mayan ruins. NASA added the island of Hisapaniola to the itinerary to help study faults in both Haiti and the Dominican Republic.

"UAVSAR will allow us to image deformations of Earth's surface and other changes associated with post-Haiti earthquake geologic processes, such as aftershocks, earthquakes that might be triggered by the main earthquake farther down the fault line, and the potential for landslides," JPL's Paul Lundgren, the principal investigator for the Hispaniola overflights, said in a press release Wednesday.

"Because of Hispaniola's complex tectonic setting, there is an interest in determining if the earthquake in Haiti might trigger other earthquakes at some unknown point in the future," Lundgren said, "either along adjacent sections of the Enriquillo-Plantain Garden fault that was responsible for the main earthquake, or on other faults in northern Hispaniola, such as the Septentrional fault."

The UAVSAR, which left NASA's Dryden Flight Research Center in Edwards, Calif., on Jan. 25, will flyover Hispaniola multiple times this week and again in early February.

Since November 2009, the radar has been mapping the San Andreas and other major faults in California. The 3-D data will help scientists better understand the state's seismic risk.

UAVSAR works by sending microwaves to the ground from a pod under the aircraft flying at about 41,000 feet and recording the return signal. The differences in the times it takes waves to return from points on the ground to the plane gives information about the topography. By hitting the same target from different angles as the plane flighs overhead, a 3-D image can be made. Very precise details about ground motion can be calculated by flying over the same area later, giving scientists information about strain buildup on a fault.

The Hispaniola data will be made public in a few weeks. The Dominican Republic flyovers could help scientists understand future earthquakes on the Septentrional fault.

Images: 1) NASA's UAVSAR airborne radar will create 3-D maps of earthquake faults over wide swaths of Haiti (red shaded area) and the Dominican Republic (yellow shaded area)./NASA. 2) Dave Bullock/Wired.com

Nombre: Juan J. Núñez C.

Asignatura: CAF

Pág. web: http://www.wired.com/wiredscience/2010/01/nasa-radar-to-map-haiti-faults/

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