EO-1 (Earth Observing - 1), USA


Earth Observing-1 (EO-1) is the first satellite in NASA's New Millennium Program Earth Observing series. EO-1 was launched on 21 November 2000.The EO missions will develop and validate instruments and technologies for space-based Earth observations with unique spatial, spectral and temporal characteristics not previously available.

EO-1's primary focus is to develop and test a set of advanced technology land imaging instruments. However, many other key instruments and technologies are part of the mission and will have wide ranging applications to future land imaging missions in particular and future satellites in general. EO-1 is inserted into an orbit flying in formation with the Landsat 7 satellite taking a series of the same images. Comparison of these "paired scene" images will be one means to evaluate EO-1's land imaging instruments.

A unique feature of the EO-1 mission is that it carries an experimental hyperspectral imager (the Hyperion) that can capture high resolution images of the earth surface in 220 contiguous spectral bands.

EO-1 Orbit

Type Sun-Synchronous, 10:01 am descending node
Altitude 705 km
Inclination 98.2 deg
Period 99 min
Repeat Cycle 16 days

EO-1 Sensors

  • Hyperion:The Hyperion is a high resolution hyperspectral imaging instrument. The Hyperion images the earth's surface in 220 contiguous spectral bands with high radiometric accuracy, covering the region from 400 nm to 2.5 µm, at a ground resolution of 30 m. Through this large number of spectral bands, complex land eco-systems can be imaged and accurately classified.

    The Hyperion is a "push broom" instrument. It has a single telescope and two spectrometers, one visible/near infrared (VNIR) spectrometer (with CCD detector array) and one short-wave infrared (SWIR) spectrometer (HgCdTe detector array).

    Hyperion Sensor Characteristics
    Spatial Resolution 30 m
    Swath Width 7.75 km
    Spectral Channels 220 unique channels. VNIR (70 channels, 356 nm - 1058 nm), SWIR (172 channels, 852 nm - 2577 nm)
    Spectral Bandwidth 10 nm (nominal)
    Digitization 12 bits
    Signal-to-Noise Ratio (SNR) 161 (550 nm); 147 (700 nm); 110 (1125 nm); 40 (2125 nm)

  • ALI (Advanced Land Imager): The ALI instrument features ten-meter ground resolution in the panchromatic (black-and-white) band and 30-meter ground resolution in its multispectral bands (0.4-2.4 microns), covering seven of the eight bands of the current Landsat.
  • AC (Atmospheric Corrector):The AC instrument provides the first space-based test of an Atmospheric Corrector for increasing the accuracy of surfacereflectance estimates. The AC enables more precise predictive models to be constructed for remote sensing applications. It willprovide significant improvements in generating accurate reflectance measurements for land imaging missions. Covers the0.890-1.600 micron wavelength IR band.

Link to: EO-1 Web Site (http://eo1.gsfc.nasa.gov) at Goddard Space Flight Center, NASA, USA.
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Copyright CRISP, 2001
Please send comments/enquiries/suggestions about this tutorial to Dr. S. C. Liew at scliew@nus.edu.sg