X-SAR Multi Look, Ground Range, Detected Product (MGD, held at DLR/DFD)
Entry ID:
DFD-X-SAR.SAR.MGD
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Summary
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: Start_Date: 1994-04-09 Stop_Date: 1994-04-20 - Space ... Shuttle Mission STS-68: Start_Date: 1994-09-30 Stop_Date: 1994-10-11 Worldwide coverage and map prints are available on World Wide Web (see below). Data Set Content: The MGD data set contains range and azimuth compressed SAR image data which are detected and projected on the earth ellipsoid. The number of range and azimuth looks are variable, depending on the mission parameters selected. These are in particular the incidence angle, the PRF and the coarse or fine resolution mode. The image pixels are detected and their amplitudes are quantized with 16 bits per sample. Information regarding instrument and platform as well as processing, calibration and image quality is appended. The product is presented in range-line order. Range lines are deskewed to zero Doppler lines and organised in ascending time reference. The data set contains a scene of 100 km in sensor flight direction and a maximum of 62.5 km across track. The actual swath width, which can be smaller, is dependent on the chosen mission parameters like the incidence angle. Intended Use: This is the standard bulk product of the German and Italian PAF for X-SAR. It is compatible with the standard detected ground range image produced by JPL for the SRL L- and C-band and can be used for all applications which require no geocoded or complex data. Input Data: - X-SAR raw data and ancillary data from HDDC - Orbit data from the PATH tape Processing Algorithm: Signal processing is performed by two-dimensional matched filtering in range and azimuth direction. Windowing is applied to meet the specified PSLR and ISLR values. Doppler parameters are calculated from orbit data and the SAR raw data itself, during a preprocessing step. The azimuth processing bandwidth is selected according to the used PRF in order to guarantee the specified 'Signal to Azimuth Ambiguity Ratio' SAAR. The effective number of looks in range and azimuth are chosen to maintain a spatial resolution of 25 m by 25 m. In case the inherent spatial resolution is higher, the number of looks will be increased. Hence, it is the processing strategy to fix the spatial resolution and to vary the radiometric resolution by the number of looks used in range and azimuth direction. (Those users who are interested in full spatial resolution may use the 'X-SAR.SAR.SSC' product.) The look processing is either performed in the frequency domain or by a weighted time domain pixel averaging. The projection to ground range is done by a one-dimensional interpolation. Resampling and detection is performed to achieve a 12.5 m by 12.5 m pixel spacing. Due to the nonlinear nature of the Slant-to-Ground range projection the ground range resolution in the MGD product will vary slightly over range. The specified value for the spatial resolution is therefore only applicable for mid-swath. Calibration: The MGD product is fully calibrated. Product Parameter: Equivalent number of looks in azimuth 1.5 - 2.5 in range 1 - 3 Geometric representation ground range ellipsoid used GEM6 Data representation detected, amplitude pixel quantization 16 bit, signed integer Ground area covered azimuth >= 100 km range <= 62.5 km Product orientation zero Doppler coordinates ISLR (1-D) > 14 dB PSLR (1-D) > 17 dB SAAR >= 17 dB for PRF <=1440 Hz >= 20 dB for PRF >=1488 Hz Spatial Resolution azimuth 25 m at mid swath range 25 m at mid swath Absolute location error azimuth: 3.0 km gr. range: < 3.9 km Pixel spacing azimuth 12.5 m Pixel spacing range 12.5 m Number of pixels azimuth >= 8000 range <= 5000 Image data volume up to 80 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: http://www.dfd.dlr.de and clicking on `Information Services (ISIS)` or `Accessing ISIS` (telnet). ISIS can also be accessed by telnet directly: input: telnet isis.dfd.dlr.de user: dlrpid password: - 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 Center Contact. 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: http://eoweb.dlr.de:8080/index.html
Geographic Coverage
(Click for Interactive Map)
Spatial coordinates
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N: 70.0
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S: -70.0
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E: 180.0
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W: -180.0
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Temporal Coverage
Start Date:
1994-04-09
Stop Date:
1994-10-11
Data Resolution
Latitude Resolution:
25m
Longitude Resolution:
25m
Personnel
Role:
INVESTIGATOR
Phone:
+39-55-4796-269
Fax:
+39-55-4796-441
Contact Address:
Facolta D'Ingegneria
Via S. Marta, 3
City:
Firenze
Postal Code:
I-50139
Country:
Italy
Role:
TECHNICAL CONTACT
Phone:
+49-8153-281390
Fax:
+49-8153-281446
Email:
noack at dfd.dlr.de
Contact Address:
DLR/DFD Oberpfaffenhofen
Muenchner Str. 20
City:
Wessling
Postal Code:
D-82234
Country:
GERMANY
Role:
INVESTIGATOR
Phone:
+49-8153-28-2365
Fax:
+49-8153-281465
Contact Address:
DLR/DFD Oberpfaffenhofen
Muenchner Str. 20
City:
Wessling
Postal Code:
D-82234
Country:
GERMANY
Role:
DIF AUTHOR
Phone:
+49-8153-281400
Fax:
+49-8153-281343
Email:
schroete at dfd.dlr.de
Contact Address:
DLR/DFD Oberpfaffenhofen
Muenchner Str. 20
City:
WESSLING
Postal Code:
D-82234
Country:
GERMANY
Role:
TECHNICAL CONTACT
Phone:
+49-8153-28-2397
Fax:
+49-8153-281449
Contact Address:
DLR/DFD Oberpfaffenhofen
Muenchner Str. 20
Province or State:
WESSLING
Postal Code:
D-82234
Country:
GERMANY
Publications/References
NASA/JPL publication 93-29, "SIR-C/X-SAR Mission Overview", December 15, 1993 Schreier, G. , SAR Geocoding: Data and System Wichmann-Verlag, Karlsruhe, Germany, 1993 M. Zink, R. Bamler, "X-SAR Radiometric Calibration and Data Quality", IEEE Transactions on Geoscience and Remote Sensing, Vol. 33, 1995 ... Hartmut Runge, Helko Breit, Ulrich Steinbrecher, Mihai Datcu, "Higher Resolution X-SAR Images", IEEE International Geoscience and Remote Sensing Digest 1995. M. Eineder, R. Bamler, H. Breit, U. Steinbrecher, "X-SAR Data Quality - The Results of Two Missions", IEEE International Geoscience and Remote Sensing Digest 1995. R. Bamler, M. Eineder, H. Breit, U. Steinbrecher, "X-SAR Data and Image Quality", IEEE International Geoscience and Remote Sensing Digest, 1994, pp. 1175-1177. Richard Bamler, "Wavelength Diversity PRF-Ambiguity Resolver : Calibration and Test for ERS-1 SAR", IEEE International Geoscience and Remote Sensing Digest 1993. Richard Bamler, Dieter Just, "Phase Statistics and Decorrelation in SAR Interferograms", Remote Sensing Digest 1993. Richard Bamler, Helko Breit, Ulrich Steinbrecher, Dieter Just, "Algorithms for X-SAR Processing", Remote Sensing Digest 1993. H. Runge, "The German Processing and Archiving Facility for X-SAR", EUSAR '96, Koenigswinter, Germany, 1996
Creation and Review Dates
Last DIF Revision Date:
2008-09-29
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