April 2004

In this Issue

Basics		Using Remote Sensing To Monitor and Manage the Coastal Environment
Image Data Corner		Coastal Geospatial Information
Tech Tip		Tips for selecting pixels for an IMAGINE Subpixel Classifier Training Set
New Advancements		Identifying and Locating Anomalies
Success Stories		Do you have an Interesting Application?
Hot Sites		Web sites related to Coastal Remote Sensing
AAI News		Announcing Upcoming Presentations by AAI Recent Publications by AAI IMAGINE Subpixel Classifier Version 8.7 AAI's New Web site Employment Opportunities at AAI

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From the Editor

Welcome to a new issue of The Spectral Explorer! This issue examines the use of remote sensing for monitoring and managing the coastal environment. According to the EPA's National Coastal Condition Report (EPA842-F-02-001, December 2001, http://www.epa.gov/owow/oceans/nccr/), "Existing data show that the overall condition of the U.S. coastal waters as fair to poor, varying from region to region and that 44% of estuarine areas in the US are impaired for human use or aquatic life use."

Remote sensing has played a key role in a variety of coastal applications including mapping coral reefs, monitoring mangrove forests, predicting harmful algal blooms and much more. With a great variety of applied uses, remote sensing promises to continue to be an important tool for effective coastal monitoring and management.

We welcome your comments, ideas, and suggestions! We are always looking to learn of new remote sensing applications with which our readers have been involved. Please send e-mail to Brenda.

Basics

NOAA Uses Remote Sensing Technology to Monitor and Identify Harmful Algal Blooms
September 30, 2003

The following article was a news release from the National Oceanic and Atmospheric Administration (NOAA) on September 30, 2003.
To learn more go to: http://www.publicaffairs.noaa.gov/releases2003/sep03/noaa03117.html

Using remote sensing technology, scientists at the National Oceanic and Atmospheric Administration (NOAA) have developed a way to identify and monitor harmful algal blooms (HABs). This monitoring will help detect HABs along the coastal areas of the US, where they are a growing concern while providing more information to managers on how to reduce the impacts of these toxic blooms. NOAA is an agency of the US Department of Commerce.

Scientists from NOAA's National Centers for Coastal Ocean Science (NCCOS) are monitoring HABs using a combination of ocean color satellite imagery with field and meteorological data.

Satellites from the Sea-viewing Wide Field of view Sensor (SeaWiFS), owned by OrbImage, provides information on the color of the water that can be used to determine characteristics of algae blooms. This satellite data, in conjunction with analysis of wind data from NOAA's National Weather Service and National Data Buoy Center, and field data from water samples provides the team with enough information to predict bloom movement, landfall, persistence and intensity.

SeaWiFS, scientists had no means other than field sampling to monitor HABs. The laborious and expensive sampling limited the ability of managers to determine the extent of the blooms.

Currently, NOAA is routinely monitoring HABs in the Gulf of Mexico. The SeaWiFS data has helped identify the extent and magnitude of the blooms. On the Florida Coast, the satellite imagery, coupled with models, has provided advanced detection of blooms, allowing the state and local officials to better direct resources for sampling. In Washington State, the technology has improved sampling and research on domoic acid, a neurotoxin produced by a diatom, which may cause permanent short-term memory loss in victims and is associated with Amnesic Shellfish Poisoning (ASP).

Upon detection of such HABs, state managers plan monitoring for shellfish beds and for stranded mammals, such as the endangered manatees, and provide advisories to local government to address beach cleanup and business concerns.

NOAA's National Ocean Service, which includes NCCOS, is dedicated to exploring, understanding, conserving and restoring the nation's coasts and oceans. It balances environmental protection with economic prosperity in fulfilling its mission of promoting safe navigation, supporting coastal communities, sustaining coastal habitats and mitigating coastal hazards.

NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of our nation's coastal and marine resources.

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Image Data Corner

Coastal Geospatial Information
http://www.csc.noaa.gov/products/datasites/

This Web site, provided by the NOAA Coastal Services Center, provides an excellent list of Internet sources for locating coast-related data. Sources listed include federal and state Web sites as well as data clearinghouses, training resources and metadata starting points. Be sure to bookmark this site as a great resource for coastal data!

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Subpixel Classifier Tech Tip

Tips for selecting pixels for an IMAGINE Subpixel Classifier Training Set

1) Quality is more important than quantity.

• If you are in an environment where your main target is likely to be confused with only a few items, then your training set need not be large. However, there should be no fewer than five pixels in the training set.

• If the Material Of Interest (MOI) is likely to be confused with many other features in the image, then a larger training set will be needed.

• Keep in mind that it is possible that the software can find different combinations of material common to the training pixels other than the main target for which the user is looking. For example, the derived signature may actually target soil around a tree, instead of the tree itself. A smaller training set can often minimize this possibility.

2) The pixels selected for the training set should contain as much of the MOI as possible.

• Signatures can be derived from pixels containing as little as 20% of the MOI, but the quality of the signature is generally higher when the training pixels contain larger material fractions.

• An IMAGINE Subpixel Classifier training set can be derived using either a whole pixel or subpixel training set. If a subpixel training set is utilized, the signature derivation process extracts the subpixel component that is common to all pixels in the training set, yielding a result that is equivalent to a whole pixel reference signature of that common material.

3) The selected pixels should sample the natural variation in the spectral properties of the
MOI.

• It is possible that extreme variations in the spectral properties of the MOI may require more than one signature.

• Look at the whole pixel spectra. The training set pixels should have similar (although not necessarily identical) shapes.

4) The pixels should cover a diversity of backgrounds.

• In general, the more diverse the background is, the more pixels that should be included in the training set.
  

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New Advancements in Remote Sensing at AAI

Identifying and Locating Anomalies

Supervised Anomaly Finder (SAF) is a tool being developed at AAI to identify patterns in residuals to locate specific spectral variations that are indicative of very small fractional occurrences of materials or changes in the material, such as burn marks on trees or the emergence of flowers on vegetation. This process can be a powerful tool when used in conjunction with IMAGINE Subpixel Classifier as it can locate pixels with material fractions of the target smaller than that which would be detected by IMAGINE Subpixel Classifier alone. SAF utilizes Image Calibrator to calculate and report the reflectance spectrum of the anomalous material. The reported sizes and reflectance spectra permit the detected anomalies to be classified and identified. The applications for which SAF may prove valuable vary greatly. One such application is identifying the location of submerged aquatic vegetation in a waterbody. For more information about AAI's Supervised Anomaly Finder, feel free to contact us at 978-663-6828 or visit http://www.discover-aai.com/company/contact.htm.

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Success Stories

Users of IMAGINE Subpixel Classifier vary widely, from private firms and universities to nonprofit organizations and government agencies, resulting in a diverse array of applications. If you have an interesting application utilizing IMAGINE Subpixel Classifier that you would like to share, we'd love to hear about it and highlight it in our newsletter. Feel free to contact Brenda at 978-663-6828 or e-mail her.

Hot Sites

NOAA Coastal Services Center - Remote Sensing for Coastal Management

http://www.csc.noaa.gov/crs/rs_apps/
This useful Web site provides many examples of applied uses of remote sensing for coastal management such as establishing beach setback lines, mapping coral reefs, managing nuisance aquatic plants, and monitoring harmful algae. It also provides information about a variety of sensors that have proven useful for coastal remote sensing.

USGS Coastal and Marine Environments Research and Applications

http://terraweb.wr.usgs.gov/coastal.html
This Web site provides information on several projects conducted by the US Geological Survey that utilize remote sensing to study coastal and marine environments. Examples include mapping the seafloor of the Monterey Bay region and change detection in San Francisco Bay.

The Use of Remote Sensing and GIS in the Sustainable Management of Tropical Coastal Ecosystems.

http://www.vub.ac.be/APNA/staff/FDG/pub/RS&GIS.pdf
This article highlights selected case studies of the use of remote sensing and GIS for management of mangrove forests, seagrass beds and coral reefs in Southeast Asia, Africa and South America.

Monitoring Mangrove Forests using Remote Sensing and GIS

http://www.gisdevelopment.net/aars/acrs/1999/ps5/ps5126.shtml
This paper examines the use of three different RADAR satellite imaging systems (JERS-1, ERS-1, Radarsat) and three different optical satellite systems (Landsat MSS, SPOT-XS, Landsat TM) to detect mangrove deforestation in the delta of the Mahakam River in Indonesia.

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AAI News

Recent and Upcoming Presentations by AAI

Dr. Scott Stoodley, AAI's Director of Environmental Programs, will be presenting at two conferences this spring. His presentation is entitled "Monitoring Water Quality in Choctawhatchee Bay, Florida via Remotely-sensed Data" and was delivered at the Oceanology International Conference in London this March and will be presented at The Coastal Society's 19th Biennial Conference in Newport, RI this May.
For more information on these two conferences, please visit the following Web sites: http://www.oceanologyinternational.com/conference/programme.asp
http://thecoastalsociety.org/conference/tcs19/

Recent Publications by AAI

AAI recently had the following two articles published in the January 2004 issue of Photogrammetric Engineering & Remote Sensing. Click on the links below to view the abstracts and to access downloadable .pdf files of the full articles.

"Automated Subpixel Photobathymetry and Water Quality Mapping," R. Huguenin, M. Wang, R. Biehl, S. Stoodley, and J. Rogers, Photogrammetric Engineering & Remote Sensing Vol. 70, No. 1, January 2004, pp. 111-123. >>> Get the white paper

New photobathymetry and water quality software is described that utilizes subpixel analysis software with an autonomous image calibration procedure and analytic retrieval algorithm to simultaneously retrieve and report bottom depth and concentrations of suspended chlorophyll, suspended sediments, and colored dissolved organic carbon on a per-pixel basis from four-band multispectral image data.

"AVIRIS Measurements of Chlorophyll, Suspended Minerals, Dissolved Organic Carbon and Turbidity in the Neuse River, NC," M. Karaska, R. Huguenin, J. Beacham, M. Wang, J. Jensen, and R. Kaufmann, Photogrammetric Engineering & Remote Sensing Vol. 70, No. 1, January 2004, pp. 125-133. >>> Get the white paper

Thematic maps of each water quality parameter were generated from the imagery; the maps of chlorophyll showed spatial patterns consistent with field data and circulation of the river, and indicated potential point and non-point sources of algae blooms.

In addition, Sandra Nierzwicki-Bauer, Executive Director of the Darrin Fresh Water Institute (DFWI), presented the results of a project conducted by AAI at the 23rd International Symposium of the North American Lake Management Society. The following abstract was published in the conference proceedings.

Nierzwicki-Bauer Sandra, R. Huguenin, S. Stoodley and B. Taylor. "Use of Landsat Thematic Mapper Data in Monitoring Water Quality in Lake George, New York." Abstract published in Proceeds of NALMS 2003: 23rd International Symposium. Mashantucket, Connecticut. November 4th - 8th, 2003.

For more information on this project, visit DFWI's Web site at
http://www.rpi.edu/dept/DFWI/dfwiwq/wq_index.html.

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IMAGINE Subpixel Classifier Version 8.7

AAI's New Web site
www.discover-aai.com

AAI has completely restructured and redesigned its Web site to better reflect what the company offers customers. The new site emphasizes AAI's expertise in professional services and environmental monitoring as well as algorithm development and image processing software. Besides introducing visitors to the company and its capabilities, the site provides software support and documentation, white paper downloads, and links to leading satellite image providers.

Employment Opportunities at AAI

AAI currently has the following employment position available: Remote Sensing/Image Processing Specialist. For more information about this position and instructions on how to apply, please visit AAI Jobs .

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