Technical Summary of LightSAR Mission Design
LightSAR will generate data for commercial, Earth science, and civilian applications.
LightSAR will enable unique capabilities, including—
- Mapping of surface change. LightSAR’s repeat-pass interferometry
technique will enable continuous monitoring of Earth’s dynamic topography to
a height accuracy of within a few millimeters.
- Better discrimination of texture and water content. Longer (L-band)
wavelength radar and use of multiple polarization modes would allow better
distinction of textures, vegetation structures and water content, soil moisture,
ice thickness, and numerous other applications.
- Long-term observations. Mission life expectancy would be five years.
- Higher-resolution images. Imaging swaths of 100-km (60 miles) wide will provide 25-m (about 83-foot) horizontal resolution, accurate to within a few millimeters vertically. Even higher resolution, 1-3 meters (3-10 feet), is being considered in order to provide opportunities for additional commercial applications, such as detailed topographic mapping.
- Continuous monitoring of changing conditions. LightSAR's 8-10-day repeating orbit (determined by the Global Positioning System, GPS), would provide visibility of most locations on Earth about once each day.
State-of-the-art technologies with significant reduction in mass, as well as instrument and mission life-cycle costs.L-band, multipolarization, high-performance SAR with multiple resolutions and swath imaging capabilities. X-band or C-band is being considered for very high-resolution commercial applications.
Multiple Imaging modes:
SpotlightAspect: Right or left looking.
High-resolution Strip
Dual Polarization
Quad Polarization
Repeat Pass Interferometric
ScanSARFrequency: 1.2575 GHz (L-band), 9.6 GHz for potential addition of X-band or 5.3 GHz for C-band.
Antenna: Electronic beam steering to maximize the targetable swath.
Electronics may include a cross-link transceiver/timing synchronizer to accommodate future synchronization of two radar platforms for real-time interferometry. Five commandable bandwidths to optimize resolution and data rate vs. incidence angle.
Antenna size: 10.8 m (azimuth) x 2.9 m (elevation) for L-band. Not yet determined for X- or C-band.
Polarization: HH, HV, VH, VV for L-band. Not yet determined for X- or C-band.
Peak power: 8,000 W.
Pulse width: 15, 3 µsec.
Nominal PRF: 1,600 Hz.
Sample size (bits/sample): 8,4 (BFPQ), 4 (no BFPQ).
Launch 2001/2002 time frame.
For more detailed information, see the LightSAR Reference Mission document (Adobe Acrobat file).