HR: 0800h
AN: G51C-0860    [Abstracts]
TI: Mitigating atmospheric noise for InSAR with a high-resolution weather model
AU: * Foster, J
EM: jfoster@soest.hawaii.edu
AF: SOEST, Univ of Hawaii, POST 602 1680 East West Road, Honolulu, HI 96822 United States
AU: Brooks, B
EM: bbrooks@soest.hawaii.edu
AF: SOEST, Univ of Hawaii, POST 602 1680 East West Road, Honolulu, HI 96822 United States
AU: Cherubini, T
EM: tiziana@hawaii.edu
AF: SOEST, Univ of Hawaii, HIG 350 2525 Correa Road, Honolulu, HI 96822 United States
AU: Shacat, C
EM: cshacat@soest.hawaii.edu
AF: SOEST, Univ of Hawaii, POST 602 1680 East West Road, Honolulu, HI 96822 United States
AU: Businger, S
EM: businger@soest.hawaii.edu
AF: SOEST, Univ of Hawaii, HIG 350 2525 Correa Road, Honolulu, HI 96822 United States
AB: For Hawaii, and many other regions of the world, the biggest source of noise for interferometric synthetic aperture radar (InSAR) is the differential delay caused by changes in the distribution of water vapor in the atmosphere. The radar signal is refracted by the atmosphere, and an increase in the amount of atmospheric water vapor between the acquisition times appears as an apparent increase in the distance to the ground surface, indistinguishable from real ground motion. Atmospheric effects can range over all wavelengths, with amplitudes of several centimeters or even greater, leading to inevitable difficulties in identifying and interpreting deformation events captured by InSAR. The problem is particularly acute for the Island of Hawaii, with its moist, heterogeneous tropical atmosphere, and a strong, highly variable interaction between winds and the huge volcanoes (4000 m high) that form the island. As a consequence, although the two active volcanoes, Kilauea and Mauna Loa, are rich sources of deformation signals from the interplay of volcanic and tectonic forces, these signals are typically difficult to isolate in single InSAR differential pairs. Traditional efforts to mitigate atmospheric effects have revolved around using a large number of SAR scenes to filter out the atmosphere. Although this approach has demonstrated it's practical utility it requires large quantities of data and may not be well suited to deformation events with highly variable rates and complex sources such as those often occurring on Kilauea and Mauna Loa. In order to increase the signal to noise ratio for InSAR over short time spans so that these events can be more accurately modeled and interpreted it is necessary to adopt a more sophisticated approach to dealing with the atmospheric component. In support of the astronomical facility on Mauna Kea, the Mauna Kea Weather Center runs a high resolution weather model. This model provides us with a unique opportunity to investigate the possibility of predicting the atmospheric delays for each scene of an InSAR pair. The predicted delays can be used to generate a synthetic interferogram that can be compared with the observed interferogram and subtracted from it, reducing the atmospheric noise and improving our ability to identify and resolve the geodetic signals.
DE: 1241 Satellite geodesy: technical issues (6994, 7969)
DE: 3374 Tropical meteorology
DE: 8485 Remote sensing of volcanoes
SC: Geodesy [G]
MN: Fall Meeting 2005