OTHER Satellite Systems
MODISASTERSPOTIKONOSQUICKBIRD?
Earth Observation System (EOS) “terra” and “aqua” are the actual satellites… Terra (EOS AM) and Aqua (EOS PM) ‘Terra's’ orbit around the Earth is timed so
that it passes from north to south across the equator in the morning
‘Aqua’ passes south to north over the equator in the afternoon
http://ivanova.gsfc.nasa.gov/outreach/Terra_CD-01/start.htm
Instruments on Terra and Aqua
MODIS (Moderate Resolution Imaging Spectroradiometer )detectors measure 36 spectral bands
between 0.405 and 14.385 µm viewing swath width of 2,330 km and
views the entire surface of the Earth every one to two days
acquires data at three spatial resolutions -- 250m, 500m, and 1,000m
http://modis.gsfc.nasa.gov/data/
MODIS data12 bit data in 36 spectral bands
28= 8 bit data = 256 unique212=12 bit data = 4096 unique values
http://modis.gsfc.nasa.gov/about/specs.html
The advantage of 12 bit data…. Higher digital resolution
Higher display resolution….
Except that humans can ‘only’ discriminate between 10 million colors
ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer)The spatial resolution varies with
wavelength: 15 m in the visible and near-infrared 30 m in the short wave infrared 90 m in the thermal infrared (TIR).
Each ASTER scene covers an area of 60 x 60 km.
Systeme Pour l’Observation de la Terre (SPOT)
French Satellite systemCommercial orientation 2.5-20 meter pixel resolutionPushbroom scannerOff nadir viewing capability (stereo
images)
IKONOS launched in September 1999 Normal scene 11km X 11 km4 channels of multispectral data at 4 m
resolution one panchromatic channel with 1 m
resolution 11 bits per pixel (2048 values)
1 meter pan-chromatic IKONOS image of Sidney AU
Archived scenes $7.70 X 49 = 377.40…. New scenes ~ $2500
Quickbird Launched October 18, 2001 11 bit data 61-cm (2-ft) panchromatic Panchromatic
(Black & White) 445 to 900 nanometers
2.44-m (8-ft) multispectral Blue: 450 to 520 nanometers Green: 520 to 600 nanometers Red: 630 to 690 nanometers Near-IR: 760 to 900 nanometers
http://www.digitalglobe.com/press/imagesinthenews.shtml