the prisma hyperspectral instrument design
- Paper number
IAC-08.B1.3.3
- Author
Mr. Demetrio Labate, Selex Galileo, Italy
- Coauthor
Mr. Lorenzo Giunti, Selex Galileo, Italy
- Coauthor
Mr. Massimo Ceccherini, Selex Galileo, Italy
- Coauthor
Mr. Andrea Cisbani , Selex Galileo, Italy
- Coauthor
Mr. Mauro Melozzi, Selex Galileo, Italy
- Coauthor
Mr. Stefano Pieraccini, Selex Galileo, Italy
- Coauthor
Mr. Moreno Stagi, Selex Galileo, Italy
- Coauthor
Dr. Claudio Galeazzi, Italian Space Agency (ASI), Italy
- Coauthor
Mr. Vittorio De Cosmo, Italian Space Agency (ASI), Italy
- Year
2008
- Abstract
PRISMA (PRecursore IperSpettrale della Missione Applicativa) Hyperspectral Instrument is an advanced hyperspectral sensor including also a panchromatic camera at medium resolution. Pushbroom concept based, it provides hyperspectral images of the Earth at 30 meter spatial resolution, 30 km swath width in about 200 spectral bands at spectral resolution better than 10 nm. Spectral range is from 0.4 micron to 1.010 micron (VNIR) and from 0.920 micron to 2.505 micron (SWIR). Panchromatic images are instead provided at higher resolution (5 m), coregistered to the hyperspectral ones, so to allow testing of images fusion techniques. The PRISMA Hyperspectral Instrument is the focus of the new Earth Observation mission that a consortium of Italian companies has started developing under contract of Agenzia Spaziale Italiana (ASI). The launch of this mission is scheduled in the middle of 2011. Once in orbit, the Instrument will be used as testbed for the evaluation of on-orbit issues and to verify the compliance of its specifications with several different users needs. Key features of the Instrument are the very high requirement for Signal-to-Noise and the high quality of data that have to be provided. The PRISMA instrument consists of two physical units: an Optical Head (POH) and a Main Electronics (PME). The POH includes optical systems, thermal hardware, in-flight calibration system, high-speed focal planes and proximity electronics. The PME contains the interface for scientific data acquisition, instrument control electronics and power distribution module. The instrument is characterized by very high SNR. In fact, a SNR shall be > 200 for VNIR and SWIR ranges but taking into account a specific request of SNR > 600 near 650 nm and SNR > 400 near 1550nm. To meet these demanding figures the optical system has been based on a high transmittance optical system, including a single mirror telescope and two prism spectrometers based on an innovative concept to minimize number of optical elements, while high performance detectors have been chosen for the photon detection. To provide the requested data quality for the entire mission lifetime an accurate calibration unit (radiometric and spectral) will be included in the Instrument optomechanical assembly. The data coming periodically through the use of this unit will complement the data acquired on-ground during the calibration phase.
Also the thermo-mechanical design of the instrument is based on some innovative concepts, considering that the use of prism spectrometers implies a tight control of temperature variations to guarantee the stability of all instrument features once in orbit. Considering the requirements in terms of lifetime (> 3 years), the cooling of FPAs has been based on a passive concept (e.g.: use of radiators) to avoid the drawbacks of limited lifetime of cryocooler and induced vibrations. A very critical point in the design of hyperspectral instruments is the need to manage a great amount of data coming from the detectors; therefore particular effort was devoted to the development of the entire electronics chain, considering that the total data rate coming out from the three focal planes during images acquisition is about 600 Mbps. The presented paper describes the concepts and design principle of the PRISMA Hyperspectral Instrument, at the present status of development.
- Abstract document
- Manuscript document
IAC-08.B1.3.3.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.