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High-Resolution Topography from MESSENGER Orbital Stereo Imaging – The H7 Quadrangle „BEETHOVEN“ Jürgen Oberst 1 , Frank Preusker 1 , Alexander Stark 1 , Klaus-Dieter Matz 1 , Klaus Gwinner 1 , Thomas Roatsch 1 1 German Aerospace Center, Institute of Planetary Research, D-12489 Berlin, Germany (contact: [email protected]) #1442 Acknowledgements: The MESSENGER project is supported by the NASA Discovery Program under contracts NASW-00002 to the Carnegie Institution of Washington and NAS5-97271 to The Johns Hopkins University Applied Physics Laboratory. Alexander Stark was funded by a grant from the German Research Foundation (OB124/11-1). We thank MESSENGER’s MLA and MDIS team members for their support, especially Susan Ensor, Haje Korth, Erwan Mazarico, Gregory Neumann, Michael Reid, and Sean Solomon. H7 MDIS Stereo DTM Statistics # images 7719 Image scale 50 m - 350 m Primary camera MDIS-NAC # stereo models 28,000 # object points 5.3 billion Intersection error 40 m DTM grid 221.7 m Summary: We selected approximately 7800 narrow-angle camera (NAC) and wide-angle camera (WAC) images of Mercury acquired from orbit by MESSENGER’s Mercury Dual Imaging System (MDIS) with an average resolution of about 150 m/pixel to compute a digital terrain model (DTM) for the H7 (Beethoven) quadrangle. From these images, we identified about 28,000 stereo image combinations consisting of at least three images each. We applied sparse multi-image matching to derive approximately 160,000 tie-points representing 30,000 ground points. We used the tie-points to carry out a photogrammetric block adjustment, which improves the image pointing and the accuracy of the ground point positions in three dimensions from about 930 m to approximately 40 m. We then applied high-density (pixel-by-pixel) multi-image matching to derive about 30 billion tie-points. Benefitting from improved image pointing data, we computed about 5.3 billion surface points. By interpolation, we generated a DTM with a lateral spacing of 221.7 m/pixel (192 pixels per degree) and a vertical accuracy of about 30 m. The comparison of the DTM with Mercury Laser Altimeter (MLA) profiles reveals that the DTM is geometrically rigid and useful as a reference to identify MLA outliers or to map offsets of laser altimeter tracks, presumably caused by residual spacecraft orbit and attitude errors. Elevation [km] w.r.t. Mercury‘s reference sphere of 2439.4 km H7 MLA DTM H7 MDIS Stereo DTM -5.9 4.3 Availability from June 2017: http://pdsimage.wr.usgs.gov/archive/mess-h-mdis-5-dem-elevation-v1.0/MESSDEM_1001/DEM/QUAD/IMG/ Beethoven Vivaldi Dürer Raphael
Transcript of German Aerospace Center, Institute of Planetary Research ... · German Aerospace Center, Institute...
High-Resolution Topography from MESSENGER Orbital Stereo Imaging – The H7 Quadrangle „BEETHOVEN“
Jürgen Oberst1, Frank Preusker1, Alexander Stark1, Klaus-Dieter Matz1, Klaus Gwinner1, Thomas Roatsch1
1German Aerospace Center, Institute of Planetary Research, D-12489 Berlin, Germany (contact: [email protected])
#1442
Acknowledgements: The MESSENGER project is supported by the NASA Discovery Program under contracts NASW-00002 to the Carnegie Institution of Washington and NAS5-97271 to The Johns Hopkins University Applied Physics Laboratory. Alexander Stark was funded by a grant from the German Research Foundation (OB124/11-1). We thank MESSENGER’s MLA and MDIS team members for their support, especially Susan Ensor, Haje Korth, Erwan Mazarico, Gregory Neumann, Michael Reid, and Sean Solomon.
H7 MDIS Stereo DTM Statistics
# images 7719 Image scale 50 m - 350 m
Primary camera MDIS-NAC # stereo models 28,000 # object points 5.3 billion
Intersection error 40 m
DTM grid 221.7 m
Summary: We selected approximately 7800 narrow-angle camera (NAC) and wide-angle camera (WAC) images of Mercury acquired from orbit by MESSENGER’s Mercury Dual Imaging System (MDIS) with an average resolution of about 150 m/pixel to compute a digital terrain model (DTM) for the H7 (Beethoven) quadrangle. From these images, we identified about 28,000 stereo image combinations consisting of at least three images each. We applied sparse multi-image matching to derive approximately 160,000 tie-points representing 30,000 ground points. We used the tie-points to carry out a photogrammetric block adjustment, which improves the image pointing and the accuracy of the ground point positions in three dimensions from about 930 m to approximately 40 m. We then applied high-density (pixel-by-pixel) multi-image matching to derive about 30 billion tie-points. Benefitting from improved image pointing data, we computed about 5.3 billion surface points. By interpolation, we generated a DTM with a lateral spacing of 221.7 m/pixel (192 pixels per degree) and a vertical accuracy of about 30 m. The comparison of the DTM with Mercury Laser Altimeter (MLA) profiles reveals that the DTM is geometrically rigid and useful as a reference to identify MLA outliers or to map offsets of laser altimeter tracks, presumably caused by residual spacecraft orbit and attitude errors.
Elevation [km] w.r.t. Mercury‘s reference sphere of 2439.4 km
H7 MLA DTM H7 MDIS Stereo DTM
-5.9 4.3
Availability from June 2017: http://pdsimage.wr.usgs.gov/archive/mess-h-mdis-5-dem-elevation-v1.0/MESSDEM_1001/DEM/QUAD/IMG/
Beethoven
Vivaldi
Dürer
Raphael
