Sample Images TOPSAR digital elevation model for Fernandina (118K image)
Investigators at the Jet Propulsion Laboratory and the University of Hawaii are collaborating
on the analysis of the TOPSAR data of Fernandina Island. This image shows a digital elevation
model for the summit caldera which has been shaded so that high areas are light tones, and low
areas are dark tones. The depth of the summit caldera is over 1,100 meters. Data processed by
Howard Zebker, Harold Garbeil, and Pete Mouginis-Mark.
Fernandina - Different Viewing Perspectives (165K image)
Although a single lighting geometry can aid in the interpretation of topography, it is often
more informative to try several different viewing perspectives, such as those shown here. The
summit of Fernandina is shown under three lighting directions at 120 degrees to each other. Data
processed by Howard Zebker and Harold Garbeil.
Pre-launch EOS activities
Generate Digital Elevation Models (DEMs) for volcanoes from
TOPSAR and ERS-1 data.
Verify TOPSAR
performance and determine absolute DEM location from differential GPS receivers on TOPSAR.
Derive DEMs from three-pass analysis of ERS-1 data.
Continue to improve repeat-pass algorithm for reduction of aircraft radar interferometric data.
EOS mission activities
Continue to provide DEMs derived from radar observations of volcanoes.
When new DEMs are generated during EOS (by ASTER or MISR, or other
non-EOS instrumentation), team members will compare with older DEMs to determine changes in
volcano topography.
Some recent related publications
Zebker, HA and YP Lu (1998) Phase unwrapping
algorithms for radar interferometry: Residue-cut, least-squares, and synthesis algorithms, Jour.
Opt. Soc. Am., 15: 586-598.
Zebker, HA, RA Rosen, and S Hensley (1997) Atmospheric
effects in interferometric synthetic aperture radar surface deformation and topographic maps,
Jour. Geophys. Res., 102: 7547-7563.
Rosen, PA, S Hensley, HA Zebker, FH Webb, and EJ
Fielding (1996) Surface deformation and coherence measurements of Kilauea Volcano, Hawaii, from
SIR-C radar interferometry, Jour. Geophys. Res., 101: 23109-23125.
Zebker, HA, P Rosen, S Hensley, and PJ Mouginis-Mark
(1996) Analysis of active lava flows on Kilauea volcano, Hawaii, using SIR-C radar
correlation-measurements, Geology, 24: 495-498.
Evans, DL, J Apel, R Arvidson, R Binschadler, F
Carsey, J Dozier, K Jezek, E Kasischke, F Li, J Melack, B Minster, P Mouginis-Mark, and J van Zyl
(1995) Spaceborne synthetic aperture radar: Current status and future directions, NASA Tech. Memo
4679.
Farr, TG, D Evans, HA Zebker, D Harding, J Bufton, T
Dixon, S Vetrella, and D Gesch (1995) Mission in the works promises precise global topographic
data, EOS Trans. AGU, 76: 225, 228-229.
Madsen, SN, JM Martin, and HA Zebker (1995) Analysis
and evaluation of the NASA/JPL TOPSAR across-track interferometric SAR system, IEEE Trans. Geosci.
and Rem. Sens., 33: 383-391.
TOPSAR digital elevation model for Fernandina (118K image)
Fernandina - Different Viewing Perspectives (165K image)