The commercial satellite Multispectral Imagery threat - MSI

Military Intelligence Professional Bulletin, Jan-March, 2002 by Thomas J. Quedensley

NEARNG

At one time, the primary imagery intelligence (IMINT)threat to the United States was from the former Soviet Union. Now, through the proliferation of space-based, multispectral imaging systems for profit, nations and organizations that previously lacked access to these imagery products can use them.

The commercial space imagery market has developed high-resolution imaging technology that has both civilian and military applications. This technology has made it largely unnecessary for many potential adversaries to have their own imaging capabilities. The Defense Intelligence Agency (DIA) has published a list of operational and intelligence functions that commercial MSI systems can support. The Agency's involvement in military exercises has demonstrated the utility of MSI and helped define the requirements for multispectral data. DIA applications supported by MSI include broad-area search, contingency planning, counternarcotics, counterterrorism, current operations, disaster relief, environmental monitoring, hydrography, targeting, treaty monitoring, mapping, charting, and resource monitoring.

During the past decade, the U.S. military has acquired commercial satellite imagery to supplement national technical means. This combination has helped place the most current, accurate, and comprehensive knowledge of terrain and infrastructure quickly into the hands of mission planners. The U.S. military successfully employed commercial imagery during the Gulf War, and support missions in Somalia, Haiti, Rwanda, Bosnia-Herzegovina, and Kosovo. MSI is generally timelier than other commercial systems, may be the only information available in the early stages of a crisis or emergency, and it is often the fastest way to assess post-conflict damage and plan for reconstruction.

The most important thing to remember is that any nation, organization, or individual with the means to pay for the imagery may now acquire it. For a relatively small investment, a somewhat unsophisticated organization can develop a workable and useful imagery analysis capability without establishing an expensive and complicated infrastructure. This capability will only improve as costs decrease and hardware and software improve. "Space imagery is going to be part of the intelligence trade for the other 190 countries that haven't had access to it," says John Pike of the Federation of American Scientists in Washington, D.C. (1)

MSI System Review

MSI's analytical potential results from the sensor's ability to measure both the visible and non-visible wavelengths of the electromagnetic (EM) spectrum, and it frequently reveals more about an object than analyzing an image in only one wavelength band can. Remote-sensing satellites often carry one or more imaging sensors on-board, each providing data with unique characteristics and applications:

* Multispectral scanners (MSSs) sense energy in several narrow spectral bands simultaneously. These bands range from the ultraviolet to the infrared portion of the EM spectrum.

* The Thematic Mapper (TM) is an advanced MSS designed to achieve higher image resolution, sharper spectral separation, and greater radiometric accuracy in comparison to MSS. Thermal scanners sense only the thermal portion of the spectrum.

* Panchromatic or "PAN" imagery provides an image in the visible portion of the spectrum. This imagery essentially provides a high-resolution, black-and-white image of the targeted facility or area.

* Synthetic aperture radar (SAR) uses its own emitted energy to record characteristics of the terrain. Because atmosphere and weather have little effect on these radar systems, SAR imagery provides day-or-night and all-weather imaging capabilities.

Unlike traditional photographic cameras, MSSs record data in a digital format that we can store, manipulate, enhance, and print out on film. The resulting imagery products can support a variety of imaging applications:

* Image analysis is helpful for target area studies, broad-area search, or other applications requiring wide-area enhanced imagery. Different band configurations can enhance various terrain features. Users can "geo-reference" these images to a specific mapping projection to provide current mapping data where either no maps or outdated maps are available.

* Change detection is a spectral analysis technique that compares two reference images and highlights the changes or lack of change between them.

* Perspective view imaging is a three-dimensional image simulating the view of a given point from a specified position, altitude, and direction.

* A mosaic image uses two or more adjacent MSI images, providing contiguous coverage of a specific area of interest.

* Terrain-categorized (TERCAT) imagery is a color-coded image in which the pixels represent various spectral groups such as forest, agriculture, water, and urban areas. The resulting image is useful in determining terrain categories and analyzing the area for trafficability.

Commercial MSI is available from a variety of space-based sensors. (See Figure 1.)