Satellite Sensors

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Revision as of 14:02, 19 July 2011

Passive Imagers

SEVIRI
SEVIRI is a 50 cm-diameter aperture, line-by-line scanning radiometer, which provides image data in four Visible and Near-InfraRed (VNIR) channels and eight InfraRed (IR) channels. A key feature of this imaging instrument (Fig. 1) is its continuous imaging of the Earth in 12 spectral channels with a baseline repeat cycle of 15 min. The imaging sampling distance is 3 km at the sub-satellite point for standard channels, and down to 1 km for the High Resolution Visible (HRV) channel. (from www.esa.int)
Data access for the CREW periods here: ./crew/observations/SEVIRI

MODIS
MODIS (Moderate-resolution Imaging Spectroradiometer) is a payload scientific instrument launched into Earth orbit by NASA in 1999 on board the Terra (EOS AM) Satellite, and in 2002 on board the Aqua (EOS PM) satellite. The instruments capture data in 36 spectral bands ranging in wavelength from 0.4 µm to 14.4 µm and at varying spatial resolutions (2 bands at 250 m, 5 bands at 500 m and 29 bands at 1 km). Together the instruments image the entire Earth every 1 to 2 days.
Data access for the CREW periods here: ./crew/observations/MODIS

AVHRR
The AVHRR instrument measure the reflectance of the Earth in 5 relatively wide (by today's standards) spectral bands. The first two are centered around the red (0.6 micrometer, 0.5 THz) and near-infrared (0.9 micrometer, 0.3 THz) regions, the third one is located around 3.5 micrometer, and the last two sample the thermal radiation emitted by the planet, around 11 and 12 micrometers, respectively. (from).
Data access for the CREW periods here: ./crew/observations/AVHRR

POLDER
POLDER (POLarization and Directionality of the Earth's Reflectances) is a wide field of view imaging radiometer that has provided the first global, systematic measurements of spectral, directional and polarized characteristics of the solar radiation reflected by the Earth/atmosphere system. Its original observation capabilities have opened up new perspectives for discriminating the radiation scattered in the atmosphere from the radiation actually reflected by the surface.

MERIS
MERIS (The Medium Resolution Imaging Spectrometer Instrument) is a programmable, medium-spectral resolution, imaging spectrometer operating in the solar reflective spectral range. Fifteen spectral bands from 390 nm to 1040 nm can be selected by ground command. The instrument scans the Earth's surface by the so called "push-broom" method. Linear CCD arrays provide spatial sampling in the across-track direction, while the satellite's motion provides scanning in the along-track direction.

A-TRAIN reference instruments

CALIOP
The Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) is the primary instrument on the CALIPSO satellite, which was launched in 2005. CALIOP provides profiles of total backscatter at two wavelengths, from which aerosol and cloud profiles will be derived. The instrument also measures the linear depolarization of the backscattered return, allowing discrimination of cloud phase and the identification of the presence of non-spherical aerosols.
Data access for the CREW periods here: ./crew/observations/CALIOP

CPR
./crew/observations/CPR

AMSR
./crew/observations/AMSR

Synthetic datasets

Simulated satellites scenes can be used to validate retrieval algorithms with a 'know truth'.
Data access for the CREW periods here: ./crew/observations/SYNTHETIC