Development of InSAR tropospheric correction maps using continuous GPS data and weather models
Abstract
As part of a NASA Advanced Information Systems Technology effort, we are building upon NASA's investment in the measurement of crustal deformation from continuous GPS by developing and implementing a system that will provide tropospheric delay correction maps to the InSAR community. SIO and JPL routinely produce independent, continuous GPS station position solutions using the GAMIT and GIPSY software packages, respectively, for the western North American region, including the Plate Boundary Observatory GPS network. These solutions, as well as combined and validated products, are available via a powerful portal environment known as GPS Explorer. Tropospheric zenith delay at each station is estimated as part of the solution process, and we now aim to add tropospheric products and related portal capabilities to GPS Explorer. GPS troposphere estimates have a high temporal resolution (typically 5 minutes), which suggests application in correcting the temporally variable tropospheric artifacts that obscure detection of ground deformation in InSAR. The spacing of GPS stations, however, is generally not sufficient to resolve short-wavelength tropospheric features. To overcome this limitation, we have tested the combination of GPS zenith delay solutions with delay data derived from weather forecast products (precipitable water vapor, surface temperature, and surface pressure). InSAR solutions over a short time period (unlikely to have significant deformation), when corrected by these combined GPS and weather model maps, have a reduced RMS compared to an uncorrected interferogram.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.G31A..04M
- Keywords:
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- 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 1220 GEODESY AND GRAVITY / Atmosphere monitoring with geodetic techniques;
- 6924 RADIO SCIENCE / Interferometry;
- 8110 TECTONOPHYSICS / Continental tectonics: general