Record Search Query: [Science_Parameters: Science_Category='EARTH SCIENCE', Science_Topic='ATMOSPHERE', Science_Term='ALTITUDE']
X-SAR Geocoded Ellipsoid Corrected Data Product (GEC, held at DLR/DFD)
Entry ID: DFD-X-SAR.SAR.GEC
Abstract: Mission Objective:
Please see the relevant SIR-C/X-SAR Mission description contained in the
references and as Supplementary Information for "sensor"(X-SAR).
There were two Missions with the following time frame:
- Space Shuttle Mission STS-59:
- Space ... Shuttle Mission STS-68:
Worldwide coverage and map prints are available on World Wide Web (see below).
Data Set Content:
The GEC data set contains X-SAR detected images, represented in a uniform,
preselected cartographic presentation. The image axes (i.e. the row and
column direction of the pixels) are parallel to the cartographic coordinate
system used.The cartographic system used for worldwide reference is the
Universal Transversal Mercator System (UTM).
The product mentioned here can be produced for each region of the world,
which is imaged by the X-SAR sensor. Except for the cartographic references
and possibly maps for quality control test, it does not utilize data sets
outside the SAR image generation chain. Therefore, no terrain correction
is applied to this product. The SAR inherent geometric terrain distorsions
like layover and shadowing are not considered and degrade the absolute pixel
location accuracy to maps especially in hilly terrain.
Geocoded data will be available after availability of off-line processed
precision MGD products. Geocoded data sets can be used by the scientific or
commercial community which will refer the actual SAR data to
geographic/cartographic places. Ellipsoid corrected geocoded products are
intended for that area of applications or when relative geometric
accuracy can be dispensed with some purposes.
- The standard MGD product formatted in CEOS, including parameters used for
the slant to ground range projection.
- Orbit data from the PATH tape annotated in the MGD product
- Map projection constants to be applied.
The geocoding is based on the radargrammetric functions delivered by sensor
references and processing parameters. These are:
- orbit state and velocity
- precise range measurements by sensor and corresponding annotation
within the processor
- azimuth timing information within the processor (i.e. The range
line must be annotated with the zero-Doppler orbit time.)
- map projection formula, where geographic latitude and longitude are
transferred to appropriate map coordinates.
As ellipsoid reference is used, the discrete transformation formula will
only be computed for a mesh of discrete points. Bilinear interpolation is
performed within this grid. Oversampling is applied to avoid aliasing when
resampling to map grid. The standard resampling procedure is cubic convolution.
Equivalent no. of looks
in azimuth 1.5 - 2.5
in range 1 - 3
Geometric representation cartographic UTM
ellipsoid use WG584
Data representation detected, amplitude
pixel quantization 16 bit, signed integer
Ground area covered
azimuth > 100 km
range < 62.5 km
Spatial Resolution 25 m (determined by the MGD product)
Absolute location error < 150 m (if tiepoints can be applied
and for flat terrain)
northing 12.5 m
easting 12.5 m
Number of pixels
northing 8000 ... 8960
easting 4000 ... 8960
Image data volume up to 160 MBytes
Access to the data:
On-line access to data and information as well to digital quicklook DQL
or browse data is provided by the Intelligent Satellite Data Information
System (ISIS), developed by DLR as a client / server configuration.
It represents the interface of DLR-DFD to users, providing easy access to
catalogue-, inventory-, browse- and general textual information.
ISIS can be accessed with World Wide Web by URL:
and clicking on `Information Services (ISIS)` or `Accessing ISIS` (telnet).
ISIS can also be accessed by telnet directly:
input: telnet isis.dfd.dlr.de
Other procedures (modem or X-25) to access ISIS are described as 'Supplemen-
tary Information' for data centers (keyword 'ISIS'. Access presumes the in-
stallation of the client software (available free of charge) which can be
easily done by users (supplied by DLR/DFD).
Digital and photographic products may be ordered at DFD - Help Desk,see Data
There is also available on CD-ROM and on Web a set of image sample products
as well as general and specific information about the X-SAR missions. This
'user-kit' can be accessed via Web with URL:
Boscence, D. 1989, Biogenic carbonate production in Florida Bay, Bulletin of Marine Science, 44(1): 419-433<, University of Florida Press
Frankignoulle, M. 1988, Field Measurements of air-sea CO2 exchange, Limnology and Oceanography, 33(3):313-322, American Society of Limnology and Oceanography
Millero, F. J. 1979, The thermodynamics of the carbonate system in seawater, ... Geochimica et Cosmochimica Acta, 43:1651-1661, Geochemical Society (Elsevier Science Ltd.)
Smith, S. V., Key, G. S. 1975, 1975 Carbon dioxide and metabolism in marine environments, Limnology and Oceanography, 20:493-495, American Society of Limnology and Oceanography
Stockman, K. W., Ginsburg, R. N., Shinn, E. A. 1967, The production of lime mud by algae in South Florida, Journal of Sedimentary Petrology, 37(2):633-648, S E P M Society for Sedimentary Geology
Sugiura, Y., Ibert, E. R., Hood, D. W. 1963, Mass transfer of carbon dioxide across sea surfaces, Journal of Marine Research, 21(1):11-24, Sears Foundation for Marine Research
Wanninkhof, R. 1992, Relationship between wind speed and gas exchange over the ocean, Journal of Geophysical Research, 97:7373-7382, American Geophysical Union
Barnes, D. J. 1983, Profiling coral reef productivity and calcification using pH and
oxygen electrodes, Journal of Experimental Marine Biology and Ecology, 66:149-161, , Elsevier Science BV
Barnes, D. J., Devereux, M. J. 1984, Productivity and calcification on a coral reef: a survey using pH
and oxygen electrode techniques, Journal of Experimental Marine Biology and Ecology, 79:213-231, Elsevier Science BV
Frankignoulle, M., Disteche, A. 1984, CO2 chemistry in the water column above a Posidonia seagrass bed and related air-sea exchanges, Oceanologica Acta, 7(2):209-219, Institute Franceis de Recherche pour lapos;Exploitation de la Mer
Gattuso, J. P., Pichon, M., Delesalle, B., Frankignoulle, M. 1993, Community metabolism and air-sea CO2 fluxes in a coral reef ecosystem (Moorea, French Polynesia), Marine Ecology Progress Series, 96:259-267, Inter-Research
Kayanne, H., Suzuki, A., Saito, H. 1995, Diurnal changes in the partial pressure of carbon dioxide in coral reef water, Science, 269:214-216, American Association for the Advancement of Science
Smith, S. V. 1973, Carbon dioxide dynamics: a record of organic carbon production, respiration, and calcification in the Eniwetok reef flat community, Limnology and Oceanography, 18(1):106-120, American Society of Limnology and Oceanography
Creation and Review Dates