The Hyperspectral Infrared Imager (HyspIRI) spaceborne mission has two imaging sensors operating in the visible to shortwave infrared (VSWIR) and the thermal infrared (TIR), respectively. The HyspIRI-TIR imaging instrument is being developed for infrared mapping of the Earth in 8 spectral bands with a 5-day revisit time at the equator. The system will have 60-m ground resolution at nadir, 200-mK noise-equivalent temperature difference (NETD) for 300 K scenes, and 0.5 ºC absolute temperature accuracy. As the spacecraft moves in its polar orbit, a rotating scan mirror allows the telescope to view a 51º cross-track nadir strip, an internal blackbody target, and space, every 2.1 s. Combining the overlapping strips will yield a 51º (597-km) wide swath below the spacecraft.
The detector array will be 256×256 pixels in size and consist of 13.5-μm cutoff HgCdTe material delineated into 40-μm pixels. Eight spectral filters spanning 4 to 12 μm in wavelength will be assembled into a butcher-block assembly in close proximity to the detector array. Four columns of 256 detectors in each spectral channel will be combined using time delay and integration (TDI) to form a single 256-element-wide strip. A custom readout integrated circuit will provide the high speeds needed for the required 32-μs frame time.
This work was done by Marc C. Foote, Simon J. Hook, and William R. Johnson of Caltech for NASA’s Jet Propulsion Laboratory. NPO-48394
This Brief includes a Technical Support Package (TSP).
High-Speed Spectral Mapper
(reference NPO-48394) is currently available for download from the TSP library.
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Overview
The document is a Technical Support Package from NASA's Jet Propulsion Laboratory (JPL) that focuses on the High-Speed Spectral Mapper and the HyspIRI Thermal Infrared Radiometer (TIR). It outlines the objectives, design, and specifications of the HyspIRI TIR, which is part of NASA's Instrument Incubator Program (IIP). The TIR is designed to demonstrate key technologies for the HyspIRI mission, particularly in thermal infrared sensing.
The document details the timeline for the prototype development, indicating that assembly was set to begin in Spring 2013, with testing scheduled for Fall 2013. It emphasizes the importance of the TIR in capturing high-resolution thermal infrared data, which is crucial for monitoring land and coastal regions, as well as oceans.
Key science measurement requirements for the HyspIRI TIR are specified, including a baseline ground resolution of 60 meters, a revisit time of 5 days, and a noise equivalent delta temperature of less than 0.2 K. The instrument aims for an absolute accuracy of 0.5 K and has defined saturation thresholds for both low and high-temperature bands. The overpass time is targeted for around 10:30 AM, with the capability for nighttime imaging included as a requirement.
The TIR is expected to operate across eight spectral bands within the range of 3 to 12 micrometers, providing comprehensive coverage of land and coastal regions at a resolution of 1 km. Data latency is also a critical factor, with a goal of delivering data within 2 days, significantly improving the timeliness of information available for scientific analysis.
The document also includes contact information for further inquiries and emphasizes compliance with U.S. export regulations, indicating that the information may contain proprietary data. It serves as a resource for understanding the technological advancements in remote sensing and their potential applications in various scientific and commercial fields.
Overall, the Technical Support Package provides a concise overview of the HyspIRI TIR's design, objectives, and operational parameters, highlighting its significance in advancing Earth observation capabilities and contributing to environmental monitoring efforts.
