- Airborne Real-time Cueing Hyperspectral Enhanced Reconnaissance
__NOTOC__The Airborne Real-time Cueing Hyperspectral Enhanced Reconnaissance, also known by the acronym ARCHER, is an aerial imaging system that produces ground images far more detailed than plain sight or ordinary
aerial photographycan.cite web |url=http://www.wired.com/science/discoveries/news/2007/09/fossettcamera |title=ARCHER Supervision Camera Takes to Skies in Steve Fossett Search |author= Friess, Steve |date=2007-09-07 |work= Wired News|publisher= CondéNet, Inc |archiveurl= http://www.webcitation.org/5RjISKtc2|archivedate= 2007-09-07 |quote=ARCHER … is capable of panchromatic aerial imaging far more detailed than plain sight or ordinary photography can gather.] It is the most sophisticated unclassified hyperspectral imaging system available, according to U.S. Government officials.cite web |url=http://www.1af.acc.af.mil/shared/media/document/AFD-070808-022.pdf |title= AFNORTH Air Support Handbook (AFD-070808-022)|archiveurl= http://www.webcitation.org/5RjISKtcT|archivedate=2007-09-08 |date= 2007-08-01| work=Defense Support to Civil Authorities (DSCA) Handbook|publisher= United States Air Force|pages= p. 51 |quote=The most sophisticated unclassified HyperSpectral imaging system available.] ARCHER can automatically scan detailed imaging for a given signature of the object being sought (such as a missing aircraft),cite web |url=http://www.aviationweek.com/aw/generic/story.jsp?id=news/Foss09067.xml&headline=Advanced%20Recon%20System%20Aids%20Fossett%20Search&channel=null |title= Advanced Recon System Aids Fossett Search |accessdate=2007-09-08 |author= Fiorino, Frances |date=2007-09 |work= Aviation Week|publisher= McGraw-Hill |quote=According to CAP, a set of parameters describing the intended target, including its color and shape, is programmed into the ARCHER system.] for abnormalities in the surrounding area, or for changes from previous recorded spectral signatures.cite journal
author = Goodlin, Lt Col Douglas
date = 2007-08-03
title = Instruction 10-2701 Civil Air Patrol
url = http://level2.cap.gov/documents/CAP_USAFI_10_2701.pdf
archivedate = 2007-09-08
quote = HSI—Also referred to as 'ARCHER'. HSI is a passive sensor system that observes a target in multi-spectral bands.] It is has direct applications for
search and rescue, counterdrug, disaster reliefand impact assessment, and homeland security, and has been deployed by the Civil Air Patrol(CAP) in the United States on the Australian built Gippsland GA8Airvan fixed-wing aircraft. CAP, the civilianauxiliary of the United States Air Force, is a volunteer education and public service non-profit organizationthat conducts aircraft search and rescue in the U.S.
ARCHER is a daytime non-invasive technology, which works by analyzing an object’s reflected light. It cannot detect objects at night, underwater, under dense cover, underground, under snow or inside buildings.cite web |url=http://atg.cap.gov/downloads/FINAL%20VERSION%20ARCHER%20general%20fact%20sheet.pdf |title= Fact Sheet: Civil Air Patrol ARCHER System|accessdate=2007-09-08 |author=Alexa, Colonel Drew |date= 2005-08|publisher=
Civil Air Patrol|quote= HSI is a daytime non-invasive technology, which works by analyzing an object’s reflected light.] The system uses a special camera facing down through a quartz glassportal in the belly of the aircraft, which is typically flown at a standard mission altitude of 2500 feet (800 meters) and 100 knots (50 meters/second) ground speed.
The system software was developed by Space Computer Corporation of
Los Angeles, Californiaand the system hardware is supplied by NovaSol Corp. of Honolulu, Hawaiispecifically for CAP.cite journal
author = Stevenson, B.
coauthors = O'Connor, R.; Kendall, W.; Stocker, A.; Schaff, W.; Alexa, D.; Salvador, J.; Eismann, M.; Barnard, K.; Kershenstein, J.
year = 2005
title = Design and performance of the Civil Air Patrol ARCHER hyperspectral processing system
journal = Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XI. Edited by Shen, Sylvia S.; Lewis, Paul E. Proceedings of the SPIE,
volume = 5806
pages = 731–742
doi = 10.1117/12
quote = Each ARCHER system consists of a NovaSol-designed, pushbroom, visible/near-infrared (VNIR) hyperspectral imaging (HSI) sensor, a co-boresighted visible panchromatic high-resolution imaging (HRI) sensor, and a CMIGITS-III GPS/INS unit in an integrated sensor assembly mounted inside the GA-8 cabin. ARCHER incorporates an on-board data processing system developed by Space Computer Corporation (SCC) to perform numerous real-time processing functions including data acquisition and recording, raw data correction, target detection, cueing and chipping, precision image geo-registration, and display and dissemination of image products and target cue information.] The ARCHER system is based on hyperspectral technology research and testing previously undertaken by the
United States Naval Research Laboratory(NRL) and Air Force Research Laboratory(AFRL).CAP developed ARCHER in cooperation with the NRL, AFRL and the United States Coast Guard Research & Development Centerin the largest interagency project CAP has undertaken in its 63-year history. [cite web | url = http://www.afdw.af.mil/news/story.asp?id=123028031 | title = When information takes flight, AFDW's imagination soars | accessdate = 2007-10-31 | author = Card, Linda | publisher = United States Air ForceDistrict of Washington]
Since 2003, almost
US$5 million authorized under the 2002 Defense Appropriations Act has been spent on development and deployment. As of January 2007CAP reported completing the initial deployment of 16 aircraft throughout the U.S. and training over 100 operators, but had only used the system on a few search and rescue missions, and had not credited it with being the first to find any wreckage. [cite web |url=http://uscg.mil/hq/g-o/g-opr/nsarc/NSARCminutes18Jan07.doc |archiveurl=http://www.webcitation.org/5RjISKtcq|title= Regular Session 1-07|archivedate=2007-09-08 |author= Button, Rick |coauthors= Justice, RDML Wayne |date= 2007-01-18|format= MS Word|work= Meeting Minutes|publisher=National Search And Rescue Committee |pages= p. 4 |quote=Dr. Paul Schuda (CAP) reported that the Civil Air Patrol has completed the initial deployment of sixteen Airborne Real-time Cueing Hyperspectral Enhanced Recon…] In searches in Georgia and Maryland during 2007, ARCHER located the aircraft wreckage, but both accidents had no survivors, according to Col. Drew Alexa, director of advanced technology, and the ARCHER program manager at CAP. An ARCHER equipped aircraft from the UtahWing of the Civil Air Patrol was used in the search for adventurer Steve Fossettin September 2007. [cite web |url=http://www.nytimes.com/2007/09/07/us/07aviator.html?_r=1&ref=us&oref=slogin |title=Friends Call Missing Aviator Resourceful |accessdate=2007-09-08 |author=Friess, Steve |date= 2007-09-07|work= New York Times |quote=…a plane from the Utah Wing of the Civil Air Patrol arrived Wednesday with equipment capable of collecting hyperspectral and panchromatic images…] As of September 11, 2007 it had not located Mr. Fossett, but was instrumental in uncovering eight previously uncharted crash sites in the high desert area of Nevada, [cite web | url = http://www.nytimes.com/2007/09/11/us/11fossett.html?_r=1&ref=us&oref=slogin| archiveurl=http://www.webcitation.org/5RmyIkemX | title = F.A.A. Urges Pilots to Use a Digital Transmitter | archivedate = 2007-09-11|date = 2007-09-11 | author = Friess, Steve| work = New York Times|quote=While the Archer has not located Mr. Fossett, it has been instrumental in the discovery of at least eight previously unnoticed plane wrecks in the rugged Sierra Nevada region.] [cite web | url = http://www.usatoday.com/news/nation/2007-09-10-fossett_N.htm | title = Searchers frustrated over Fossett search | accessdate = 2007-09-14 |date = 2007-09-10| author= Associated Press| work = USA Today|quote=...search parties have spotted wreckage of eight other airplanes that had been lost for years in and around the rugged mountains of western Nevada.] some decades old. [cite web |url=http://www.montereyherald.com/ci_6836636 |title= Vast, desolate area hinders Fossett search |accessdate=2007-09-10 |author= Riley, Brendan |date=2007-09-08 |work= Monterey Herald|archivedate= |quote=…another downed plane Friday that was spotted on a hillside about 45 miles southeast of Reno … turned out to be an old crash, a plane last registered in Oregon in 1975] [cite web | url = http://www.slate.com/id/2173735/ |archiveurl= http://www.webcitation.org/5Rn7JBkZO| title = Tomb of the Unknown Aircraft: What's up with all the uncharted plane wrecks we're finding around the Sierra Nevada? | archivedate = 2007-09-11 | date = 2007-09-11| author = Lapidos, Juliet| work = Slate Magazine|quote=…before the advent of high-tech search gadgets like the ARCHER imaging system, which can identify targets as small as a motorcycle from 2,500 feet away. One of the crash sites that the Fossett team discovered might date to 1964…]
Col. Alexa described the system to the press in 2007: "The human eye sees basically three bands of light. The ARCHER sensor sees 50. It can see things that are anomalous in the vegetation such as metal or something from an airplane wreckage." Major Cynthia Ryan of the
NevadaCivil Air Patrol, while also describing the system to the press in 2007, stated, "ARCHER is essentially something used by the geosciences. It's pretty sophisticated stuff … beyond what the human eye can generally see," [cite web |url=http://afp.google.com/article/ALeqM5hu5Ip6-JjXMirJLN9fHn6oVQkv9A |archiveurl= http://www.webcitation.org/5RjISKtdI |title= High-tech plane used in hunt for adventurer Fossett |archivedate=2007-09-08 |author= Woollard, Rob |date=2007-09-05 |work= Agence France-Presse(AFP)|publisher= Yahoo! News|quote='ARCHER is essentially something used by the geosciences,' Ryan said. 'It's pretty sophisticated stuff … beyond what the human eye can generally see.' ] She elaborated further, "It might see boulders, it might see trees, it might see mountains, sagebrush, whatever, but it goes 'not that' or 'yes, that'. The amazing part of this is that it can see as little as 10 per cent of the target, and extrapolate from there." [cite web |url=http://www.news.com.au/story/0,23599,22371640-23109,00.html |title=Hi-tech plane searches for Fossett |accessdate=2007-09-08 |date=2007-08-06 |work= NEWS.com.au|publisher= News Limited |quote='It might see boulders, it might see trees, it might see mountains, sagebrush, whatever, but it goes "not that" or "yes, that",' she said.]
In addition to the primary search and rescue mission, CAP has also tested additional uses for ARCHER. [cite web |url=http://www.spacecomputer.com/systems/archer.html| archiveurl=http://www.webcitation.org/5RjISKtcz |title=ARCHER HSI System |archivedate= 2007-09-08 |publisher= Space Computer Corporation|quote=CAP has found many additional uses for ARCHER, including missions for homeland security, disaster assessment, and drug interdiction.] For example, an ARCHER equipped CAP GA8 was used in a pilot project in
Missouriin August 2005 to assess the suitability of the system for tracking hazardous materialreleases into the environment,cite web |url=http://www.dnr.mo.gov/env/hwp/hsi/hsi-project.htm |title=EPA/MoDNR Pilot Project—Characterizing Environmental Contamination Through Airborne Hyperspectral Imaging|archiveurl=http://www.webcitation.org/5RjISKtd8 |archivedate=2007-09-08 |publisher= Missouri Department of Natural Resources|quote=Missouri Department of Natural Resources … is pursuing a Pilot Project to evaluate environmental applications of ARCHER…] and one was deployed to track oil spills in the aftermath of Hurricane Ritain Texasduring September 2005. [cite web |url=http://www.af.mil/news/story.asp?id=123011957&page=3 |title=Civil Air Patrol responds |accessdate=2007-09-08 |date=2005-09-27 |work= AIr Force Link|publisher= United States Air Force|quote=A Gippsland Aeronautics GA-8 'Airvan' … came to West Houston Airport to support the assessment of Hurricane Rita.]
The major ARCHER subsystem components include:cite web |url=http://atg.cap.gov/downloads/FINAL%20VERSION%20ARCHER%20Technical%20Fact%20Sheet.pdf |title= Fact Sheet: Civil Air Patrol ARCHER System: Technical Specifications|accessdate=2007-09-08 |author= Alexa, Colonel Drew|date= 2005-08 |publisher=
Civil Air Patrol|quote=ARCHER contains an advanced hyperspectral imaging (HSI) system and a panchromatic high-resolution imaging (HRI) camera.]
hyperspectral imaging(HSI) system with a resolution of one square meter per pixel.
panchromatic high-resolutionimaging (HRI) camera with a resolution of 8 cm x 8 cm (3 in x 3 in) per pixel.
global positioning system(GPS) integrated with an inertial navigation system(INS)
hyperspectral imaging spectroscopy remote sensorobserves a target in multi-spectral bands. The HSI camera separates the image spectrainto 52 "bins" from 500 nanometers (nm) wavelengthat the blue end of the visible spectrumto 1100 nm in the infrared, giving the camera a spectral resolutionof 11.5 nm. [cite web | url = https://tests.cap.af.mil/ops/archer_training/archer_hsi_tech/glossary.cfm | title = HSI Technology — Glossary | accessdate = 2007-10-29 | work = Hyperspectral Imaging Technology for the Non-Scientist| publisher = Civil Air Patrol] Although ARCHER records data in all 52 bands, the computational algorithms only use the first 40 bands, from 500 nm to 960 nm because the bands above 960 nm are too noisy to be useful.cite web | url = https://tests.cap.af.mil/ops/archer_training/archer_hsi_tech/Hyperspectral%20&%20High%20Resolution%20Imagery.cfm | title = HSI Technology — HSI and HRI Imagery | accessdate = 2007-10-31 | publisher = Civil Air Patrol| work = ] For comparison, the normal human eye will respond to wavelengths from approximately 400 to 700 nm, [cite web | url = http://www.howstuffworks.com/light2.htm | title = "How Light Works" | accessdate = 2007-10-29 | author = Freudenrich, Craig | work = How Stuff Works] and is trichromatic, meaning the eye's cone cellsonly sense light in three spectral bands.
As the ARCHER aircraft flies over a search area, reflected
sunlightis collected by the HSI camera lens. The collected light passes through a set of lenses that focus the light to form an image of the ground. The imaging system uses a pushbroom approach to image acquisition. With the pushbroom approach, the focusing slit reduces the image height to the equivalent of one pixel. This thin, wide beam is projection onto a diffraction grating, which is a very finely etched reflecting surface that disperses light into its spectra.
The dispersed light is spread across a
charge-coupled device(CCD) similar to the image receptor in a typical digital camera, except that this CCD is also sensitive to the near infrared wavelengths up to 1100 nm. The CCD collects the spectral intensities of the dispersed light and converts them to electrical signals. The CCD output consists of electrical signals for 52 spectral bands for each of 504 image pixels. The on-board computer records the CCD output signal at a frame rate of sixty times each second. At an aircraft altitude of 2,500 ft AGL and a speed of 100 knots, a 60 Hz frame rate equates to a ground image resolution of approximately one square meter per pixel. Thus, every frame captured from the CCD contains the spectral data for a ground swath that is approximately one meter long and 500 meters wide.
A high-resolution imaging (HRI) black-and-white, or panchromatic, camera is mounted adjacent to the HSI camera to enable both cameras to capture the same reflected light. The HRI camera uses a pushbroom approach just like the HSI camera with a similar lens and slit arrangement to limit the incoming light to a thin, wide beam. However, the HRI camera does not have a diffraction grating to disperse the incoming reflected light. Instead, the light is directed to a wider CCD to capture more image data. Because it captures a single line of the ground image per frame, it is called a line scan camera. The HRI CCD is 6,144 pixels wide and one pixel high. It operates at a frame rate of 720 Hz. At ARCHER search speed and altitude (100 knots over the ground at 2,500 ft AGL) each pixel in the black-and-white image represents a 3 inch by 3 inch area of the ground. This high resolution adds the capability to identify some objects.
A monitor in the cockpit displays detailed images in real time, and the system also logs the image and
Global Positioning Systemdata at a rate of 30 Gigabytes (GB) per hour for later analysis. The on-board data processing system performs numerous real-time processing functions including data acquisitionand recording, raw data correction, target detection, cueing and chipping, precision image geo-registration, and display and dissemination of image products and target cue information.cite journal
author = Stevenson, B
coauthors = O'Connor, R.; Kendall, W.; Stocker, A.; Schaff, W.; Alexa, D.; Salvador, J.; Eismann, M.; Barnard, K.; Kershenstein, J
year = 2005
title = Design and performance of the Civil Air Patrol ARCHER hyperspectral processing system
journal = Proceedings of SPIE
volume = 5806
pages = 731
url = http://link.aip.org/link/?PSISDG/5806/731/1
archivedate = 2007-09-08
quote=ARCHER incorporates an on-board data processing system developed by Space Computer Corporation (SCC) to perform numerous real-time processing functions…
doi = 10.1117/12.604471]
ARCHER has three methods for locating targets:
*"signature matching" where reflected light is matched to spectral signatures
*"anomaly detection" using a statistical model of the
pixels in the image to determine the probability that a pixel does not match the profile, [cite web |url=http://level2.cap.gov/index.cfm?nodeID=5175 |archiveurl=http://www.webcitation.org/5RjISKtdb|title=CAP's Advanced Technologies Group: Hyperspectral Imaging |archivedate= 2007-09-08 |publisher= Civil Air Patrol, National Headquarters |quote=…signature matching (matching reflected light to spectral signatures), anomaly detection (calculates a statistical model of all the pixels in the image to see if there is a probability that a pixel does not fit).] and
*"change detection" which executes a pixel-by-pixel comparison of the current image against ground conditions that were obtained in a previous mission over the same area.
In change detection, scene changes are identified, and new, moved or departed targets are highlighted for evaluation. In spectral signature matching, the system can be programmed with the parameters of a missing aircraft, such as paint colors, to alert the operators of possible wreckage. It can also be used to look for specific materials, such as petroleum products or other chemicals released into the environment, or even ordinary items like commonly available blue
polyethylene tarpaulins. In an impact assessment role, information on the location of blue tarps used to temporarily repair buildings damaged in a storm can help direct disaster relief efforts; in a counterdrug role, a blue tarp located in a remote area could be associated with illegal activity. [cite web |url=http://www.spacecomputer.com/tools/online_tools.html |title=SCC's Real-time HSI Data Analysis and Visualization Tools|archiveurl= http://www.webcitation.org/5RjISKtdl |archivedate=2007-09-09 |publisher=Space Computer Corporation |quote=Tarp in a remote wooded area—useful for counter-drug applications.]
* [http://www.cap.gov/ Civil Air Patrol]
* [http://www.nova-sol.com NovaSol Corp.]
* [http://www.spacecomputer.com Space Computer Corporation]
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