The Aircraft Sensor Laboratory is responsible for installing, maintaining, calibrating and implementing engineering modifications on the High Altitude Missions Branch imaging sensors. These operational instruments include a variety of digital multispectral scanners and aerial mapping cameras as well as an in-flight video system. A brief description of these sensors follows.
A widely used digital multispectral scanner flown aboard the ER-2 is the Daedalus Thematic Mapper Simulator (TMS). Simulating the performance of the Thematic Mappers (TM) orbiting on Landsat 4 and 5 satellites, it replicates the spatial and spectral characteristics of the seven bands of digital data acquired by the Thematic Mapper. Four additional spectral bands are also acquired by the TMS while TM band 6 (thermal data) is acquired at full resolution in two channels in low and high gain settings. The TMS has provided data for land use and land cover analysis, forestry applications, geologic studies and disaster assessments.
The MODIS Airborne Simulator (MAS) is a modified Daedalus multispectral scanner configured to approximate the Moderate-Resolution Imaging Spectrometer (MODIS), an Earth Observing System (EOS) imaging spectrometer scheduled for orbit in the late 1990s. MODIS is designed to acquire digital imagery for measuring earth biological and physical processes and atmospheric properties. MAS records fifty channels of sixteen bit data in the visible, near infrared, mid-infrared and thermal portions of the spectrum.
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MODIS Airborne Simulator Data Sample Landforms in this scene of Atchafalaya Bay on the Louisiana coast are portrayed as a color infrared composite of bands 9 (near infrared), 2 (red) and 1 (green). Pseudo-colored water features are represented with band 45 (thermal). The bright reds and yellows portray warm water of the gulf mixing with the cooler waters (dark blues) of the Atchafalaya River drainage. |
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Airborne Ocean Color Imager Data Sample This natural color image shows silt loads carried by the Mississippi River being deposited in the Gulf of Mexico. This sensor is designed for the measurement of phytoplankton biomass and the investigation of aquatic ecosystems. |
The Multispectral Atmospheric Mapping Sensor (MAMS) is a modified Daedalus scanner flown aboard the ER-2. It is designed to study weather related phenomena including storm system structure, cloud top temperatures and upper atmosphere water vapor. The scanner retains the eight silicon-detector channels in the visible/near infrared region found on the Daedalus Thematic Mapper Simulator, with the addition of four channels in the middle and thermal infrared relating to specific water vapor absorption features.
High resolution aerial photography is collected during earth imagery acquisition missions. Cameras employed acquire photography in 9 x 9 inch (22.9 x 22.9 cm) and 9 x 18 inch (22.9 x 45.7 cm) formats. The scales of photography acquired include two mile, one mile and half-mile to the inch depending on camera lens focal lengths. Color infrared, natural color and black and white film may be used with the choice determined by investigator requirements. Multiple camera systems may be flown with a variety of film types acquiring photography at varying scales and resolutions. Photography acquired at high altitudes on the ER-2s on long duration missions can image large areas of the earth's surface in a single flight. Multispectral scanner data and photography acquired coincidentally on ER-2 missions provide unique data sets for earth science research.
Wild Heerbrugg RC-10 Mapping Cameras with a
9 x 9 inch image format are flown on virtually every ER-2 earth imaging mission. The RC-10s may be employed with six or twelve inch focal length lenses providing image scales of two miles to the inch and one mile to the inch respectively. RC-10 mounting stations include the ER-2 Q-bay, nose pod and the right and left wing pods.
Hycon HR-732 cameras are used to acquire high resolution photography in a 9 x 18 inch format. These cameras can be flown in pairs or one camera may be paired with an RC-10 mapping camera. The HR-732s acquire high resolution photography with twenty-four inch focal length lenses providing an image scale of half-mile to the inch. The large scale high resolution photography provided by these cameras is used by agencies such as the Forest Service for timber resource management and by the Fish and Wildlife Service for wetlands inventories and wildlife habitat mapping.
The Itek Iris II Panoramic Camera has been employed to acquire high resolution land use and land cover data. The Forest Service has used this camera extensively for assessing timber resources and monitoring gypsy moth defoliation in the Appalachian hardwood forests. The Iris II provides a 4.5 x 34.7 inch (11.4 x 88.1 cm) image covering 2.0 x 21.4 miles (3.2 x 34.2 km) on the ground. The high resolution twenty-four inch lens provides a scale at nadir on the panoramic image of half-mile to the inch. With its 10,000 foot film capacity the Iris II allows extended flight duration allowing photography acquisition over very large areas.