(U) A space based sensor and data exploitation system is envisioned that would augment existing and planned surveillance capabilities to detect, identify and assess activities related to nuclear, biological and chemical (NBC) facilities and delivery systems. A space based nuclear, biological and chemical detection system (SNBCDS), capable of remotely monitoring effluents that indicate the proliferation of NBC weapons of mass destruction, addresses a user identified requirement. The conceptual SNBCDS would consist of a constellation of satellites containing passive and active sensors (LIDAR based or hyperspectral imagers) that can selectively detect NBC effluents from production or storage facilities or deployed weapons. These sensors would operate in selected wavelength regions within one or more of the atmospheric transmission windows in the near ultraviolet visible (0.31-0.7 micron) and infrared (3-4, 4.5-5 and 7.5-14 microns).
(U) Several sensor systems are envisioned including: passive imaging sensors for low resolution, large area surveillance; backscatter and active sensing (LIDAR-based) (UV/IR) for higher resolution and sensitivity. Passive sensors consist of a reciever telescope, beam reduction optics, filters, a low-noise dectector and amplifying electronics package. LIDAR sensors have similar receiver characteristics, and additionally, a transmitter. Beam diagnostics and alignment mechanisms are recommended in both transmit and recieve paths. Reflective optics are recommended for most of the optical paths in order to permit common paths for UV, visual, and IR radiation. Receiver aperature diameter should be as large as possible within the constraints of satellite reliability and maintainability. A pointing gimbal in the shared T/R path is necessary to provide accurate targeting.
(U) Passive monitoring would view a region of the earth's surface suspected to contain an NBC effluent. The sensor system would monitor the attenuation of the earth's background radiation or direct thermal emission from the NBC effluent. A spectrometer or interference filter selects the spectral region imaged on the detector. The observation of characteristic absorption or emission frequencies suggests the prescence of the NBC effluent within the monitored field of view. Passive sensors would be used for wide area imaging of suspected NBC sites.
(U) Active monitoring would be performed by LIDAR dection methods such as near UV visible, IR differential absorption LIDAR (DIAL), or near UV induced fluorescence LIDAR. A space based LIDAR system would employ laser and transmitter telescope to project light pulses of selected wavelengths toward a suspected NBC effluent location. A receiver telescope located with the transmitter would observe backscattered radiation from aerosols from the targeted location. Wavelength and time dependent intensity measurements of the backscattered radiation would provide information on the type, concentration, and spatial distribution of the NBC effluent. Active sensing provides greater discrimination against interferences and a lower frequency of false alarms than passive sensing, but have smaller fields of view and greater power consumption while in use. Therefore, active sensors with greater granulation would complement wide area passive sensors.
(U) The estimated cost of the passive demonstration including launch is approximately $175 million (FY95 dollars). The anticipated cost for developing and deploying an operational satellite system with passive detection systems only is estimated to be approximately $800 million for a two satellite constellation operating for 10 years. The funding level for devloping the LIDAR system for SNBCDS will not be available until the test results of the Mid 1998 CALIOPE tests are complete. Mid 1998 CALIOPE tests will lead to the development of reliable system performance models that are needed to design and cost the active LIDAR sensing system.
(U) A possible sensing system is based on IR hyperspectral imaging in the long wave infrared (LWIR) wavelength range (7.5-13.5 microns), the molecular "fingerprint" spectral region. Operating in this spectral region allows for unambiguous identification of a large number of man made and natural materials including chemicals and other effluents. Because of the ability of the sensor system to identify surface features and materials, it could be also used to augment terrain classification and other military operational support requirements. A key feature of this concept is the extraction of relevant information from the enormous quantity of data generated by the hyperspectral sensor. Eventually, on board processing will reduce the need to download large quantities of data, but before then, much more work is needed to understand important signatures and to develop appropriate algorithms to extract the desired information. The complexity and capability of the operational system will depend on many functional trades, including the revisit time, data latency, spatial and spectral resolution, image size, and other requirements that vary with political and military conditions. A passive hyperspectral sensor has been demonstrated. The warfighter Integrated Space Technology Demonstration (ISTD) plans to demonstrate the utility of hyperspectral imagery and the ability to leverage commericial space systems.
(U) LIDAR (light dection and ranging) system concepts have been under development for NBC effluent detection by the Department of Energy's Chemical Analysis by Laser Interrogation of Proliferation Effluents (CALIOPE) program since 1993. CALIOPE is establishing an understanding of basic LIDAR phenomenology by devloping and validating models that can be used to predict LIDAR system performance. CALIOPE will establish performance criteria of possible standoff distances of LIDAR sensors from a target as well as detection sensitivities and selectivities for possible NBC effluents. CALIOPE will test LIDAR systems on the ground and on aircraft. The models developed under CALIOPE will be used in the SNBCDS development effort to help design enhanced LIDAR systems suitable for NBC effluent monitoring from space.
(U) To be supplied.
|STW Architecture||Future S&TW Architecture|
|DSP/NDS||Defense Support Program(DSP)/Nuclear Detonation (NUDET) Detection System (NDS)|
|USNDS||United States Nuclear Detonation Detection System (USNDS)|
|Space-Based Warning||Space-Based Warning Systems|
|SURVEILLANCE AND WARNING||SPACE FORCE ENHANCEMENT: SURVEILLANCE AND WARNING|
(U) Maj Tracey Kaber, Open Phone: (310) 363-6084, DSN 833-6084.
(U) 21 November 1997
(U) Road Map Production Date: 23 June 2001