Infrared filters for space-flight focal plane array applications

Infrared filters and coatings have been employed on many sensing radiometer instruments to measure the thermal emission profiles and concentrations of certian chemical constituents found in planetary atmospheres. The High Resolution Dynamics Limb Sounder ( HIRDLS) is an example of the most recent developments in limb-viewing radiometry by employing a cooled focal plane detector array to provide simultaneous multi-channel monitoring of emission from gas and aerosols over an altitude range between 8 - 70 km. The use of spectrally selective cooled detectors in focal plane arrays has simplified the optical layout of radiometers, greatly reducing the number of components in the optical train. this has inevitably led to increased demands for the enviromnetal durability of the focal plane filters because of the need to cut sub-millimeter sizes, whilst maintaining an optimal spectral performance. Additionally the remaining refractive optical elements require antireflection coatings which must cover the entire spectral range of the focal plane array channels, in this case 6 to 18µm, with a minimum of reflection and absorption. This paper describes the optical layout and spectral design requirements for filteriong in the HIRDLS instrument, and reports progress on the manufacturing and testing of the sub-millimetre sized cooled filters. We also report on the spectral and environmental performance of prototype wideband antireflection coatings which satisfy the requirements above.

Operating the Hubble space telescope : Goddard Space Flight Center : a closer look : Space Telescope Project--Goddard /

Shipping list no.: 85-926-P.

Marshall Space Flight Center.

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NASA Marshall Space Flight Center.

Mode of access: Internet.

Proceedings of a conference held at Goddard Space Flight Center, Greenbelt, Maryland, June 15-16, 1970.

Includes bibliographical references.

Models of Venus atmosphere (1972) [Prepared for NASA under the cognizance of the NASA Goddard Space Flight Center.

Cover title.

Goddard '66; a year in review at Goddard Space Flight Center, National Aeronautics and Space Administration.

Cover title.

The proceedings of a symposium held by Goddard Space Flight Center at New Carrollton, Maryland on March 5-9, 1973.

Vol. 2, edited by S. C. Freden, E. P. Mercanti, and D. E. Witten, published by Goddard Space Flight Center, Greenbelt, Md.; v. 3, edited by S. C. Freden and E. P. Mercanti, also published by Goddard.

Applied astronautics, an introduction to space flight

Mode of access: Internet.

Goddard Space Flight Center.

Cover title.

Flight Mechanics/Estimation Theory Symposium 1992 : proceedings of a symposium sponsored by NASA Goddard Space Flight Center and held at Goddard Space Flight Center, Greenbelt, Maryland, May 5-7, 1992 /

Includes bibliographical references.

Propulsion systems for space flight.

Includes bibliography.

Space flight.

v.1. Environmental and celestial mechanics. v.2. Dynamics.

Forest fires cluster detection with space-time scan statistics

Forest fires are defined as uncontrolled fires often occurring in wildland areas, but that can also affect houses or agricultural resources. Causes are both natural (e.g.,lightning phenomena) and anthropogenic (human negligence or arsons).Major environmental factors influencing the fire ignition and propagation are climate and vegetation. Wildfires are most common and severe during drought period and on windy days. Moreover, under water-stress conditions, which occur after a long hot and dry period, the vegetation is more vulnerable to fire. These conditions are common in the United State and Canada, where forest fires represent a big problem. We focused our analysis on the state of Florida, for which a big dataset on forest fires detection is readily available. USDA Forest Service Remote Sensing Application Center, in collaboration with NASA-Goddard Space Flight Center and the University of Maryland, has compiled daily MODIS Thermal Anomalies (fires and biomass burning images) produced by NASA using a contextual algorithm that exploits the strong emission of mid-infrared radiation from fires. Fire classes were converted in GIS format: daily MODIS fire detections are provided as the centroids of the 1 kilometer pixels and compiled into daily Arc/INFO point coverage.