Shuttle%20Radar%20Topography%20Mission:

1
Shuttle Radar Topography Mission Objectives and
Application
Bridget R. Smith Scripps Institution of
Oceanography Institute of Geophysics and
Planetary Physics 2002 STARS Workshop
2
Introduction What is SRTM?
How is global topography obtained?
What does the data look like?
How will the SRTM elevation map be applied?
3
What is SRTM?
SRTM Shuttle Radar Topography Mission
Mission Objectives 1.) acquire
topographic data over 80 of the Earth (60º N
and 56 S ) 2.) use C-band interferometric
synthetic aperture radar technique 3.)
complete during 11-day Shuttle mission 4.)
produce global elevation map with 30 x 30 m
spatial sampling
Space shuttle facts Speed 7.5 km/s
Altitude
233km
Earth orbits 16 times/day Mission duration
February 11th - 22nd, 2000 Total Mission
Cost 142 M
4
How is global topography obtained?
Synthetic Aperture Radar (SAR) Radar antenna
emits and receives microwave signals reflected by
surface Antenna measures back-scatter
strength and travel time (radar phase)
Calculate distance of reflection (range)
Interferometric SAR (InSAR) combine 2 radar
images Requires radar phase difference
dr range change l wavelength
5
How is global topography obtained?
InSAR
6
How is global topography obtained?
7
What does SRTM data look like?
x 2 IR color
Radar phase image
3-D elevation map
Radar image San Francisco Bay Area,
California SRTM - MRPS95918,JSC2000-E-02778 2000-0
2-21
8
Digital Elevation Map (DEM) San Diego County
9
How will the SRTM elevation map be applied?
High resolution topography can tells us about
formation history of major geologic features
San Andreas Fault
Major questions Did topography form
the San Andreas, or did the San Andreas
form topography? Can we recover information
about earthquake history from present day
topography? What extra forces do large
mountains add deep within the Earth?
10
Conclusions
SRTM mission has successfully mapped 80 of
land mass on Earth. InSAR technique of
combining two radar phase amplitude images
is the key element to swift global topography
mapping. The high resolution elevation data
of SRTM will assist in the study of land
formation history. Tectonic stress models of
topographic weight can be used to
determine crustal structure deep within the
Earth.
11
Acknowledgements
David T. Sandwell (Ph.D advisor) NASA/JPL (SRTM
Project Investigator) Julia Adame Victor
Chavez ( STARS )