scholarly journals EXTRACTING ACCURATE AND PRECISE TOPOGRAPHY FROM LROC NARROW ANGLE CAMERA STEREO OBSERVATIONS

2016 ◽  
Vol XLI-B4 ◽  
pp. 397-403 ◽  
Author(s):  
M. R. Henriksen ◽  
M. R. Manheim ◽  
E. J. Speyerer ◽  
M. S. Robinson ◽  
Keyword(s):  
Digital Terrain Models ◽  
Laser Altimeter ◽  
Narrow Angle ◽  
Digital Terrain ◽  
Terrain Models ◽  
Lunar Reconnaissance Orbiter ◽  
Geomorphic Features ◽  
Invaluable Tool ◽  
Pixel Scale

The Lunar Reconnaissance Orbiter Camera (LROC) includes two identical Narrow Angle Cameras (NAC) that acquire meter scale imaging. Stereo observations are acquired by imaging from two or more orbits, including at least one off-nadir slew. Digital terrain models (DTMs) generated from the stereo observations are controlled to Lunar Orbiter Laser Altimeter (LOLA) elevation profiles. With current processing methods, digital terrain models (DTM) have absolute accuracies commensurate than the uncertainties of the LOLA profiles (~10 m horizontally and ~1 m vertically) and relative horizontal and vertical precisions better than the pixel scale of the DTMs (2 to 5 m). The NAC stereo pairs and derived DTMs represent an invaluable tool for science and exploration purposes. We computed slope statistics from 81 highland and 31 mare DTMs across a range of baselines. Overlapping DTMs of single stereo sets were also combined to form larger area DTM mosaics, enabling detailed characterization of large geomorphic features and providing a key resource for future exploration planning. Currently, two percent of the lunar surface is imaged in NAC stereo and continued acquisition of stereo observations will serve to strengthen our knowledge of the Moon and geologic processes that occur on all the terrestrial planets.

scholarly journals EXTRACTING ACCURATE AND PRECISE TOPOGRAPHY FROM LROC NARROW ANGLE CAMERA STEREO OBSERVATIONS

2016 ◽  
Vol XLI-B4 ◽  
pp. 397-403
Author(s):  
M. R. Henriksen ◽  
M. R. Manheim ◽  
E. J. Speyerer ◽  
M. S. Robinson ◽  
Keyword(s):  
Digital Terrain Models ◽  
Laser Altimeter ◽  
Narrow Angle ◽  
Digital Terrain ◽  
Terrain Models ◽  
Lunar Reconnaissance Orbiter ◽  
Geomorphic Features ◽  
Invaluable Tool ◽  
Pixel Scale

The Lunar Reconnaissance Orbiter Camera (LROC) includes two identical Narrow Angle Cameras (NAC) that acquire meter scale imaging. Stereo observations are acquired by imaging from two or more orbits, including at least one off-nadir slew. Digital terrain models (DTMs) generated from the stereo observations are controlled to Lunar Orbiter Laser Altimeter (LOLA) elevation profiles. With current processing methods, digital terrain models (DTM) have absolute accuracies commensurate than the uncertainties of the LOLA profiles (~10 m horizontally and ~1 m vertically) and relative horizontal and vertical precisions better than the pixel scale of the DTMs (2 to 5 m). The NAC stereo pairs and derived DTMs represent an invaluable tool for science and exploration purposes. We computed slope statistics from 81 highland and 31 mare DTMs across a range of baselines. Overlapping DTMs of single stereo sets were also combined to form larger area DTM mosaics, enabling detailed characterization of large geomorphic features and providing a key resource for future exploration planning. Currently, two percent of the lunar surface is imaged in NAC stereo and continued acquisition of stereo observations will serve to strengthen our knowledge of the Moon and geologic processes that occur on all the terrestrial planets.

Fault dislocation modeled structure of lobate scarps from Lunar Reconnaissance Orbiter Camera digital terrain models

2013 ◽  
Vol 118 (2) ◽  
pp. 224-233 ◽  
Author(s):  
N. R. Williams ◽  
T. R. Watters ◽  
M. E. Pritchard ◽  
M. E. Banks ◽  
J. F. Bell
Keyword(s):  
Digital Terrain Models ◽  
Digital Terrain ◽  
Terrain Models ◽  
Modeled Structure ◽  
Lunar Reconnaissance Orbiter

scholarly journals How Well Do We Know Europa’s Topography? An Evaluation of the Variability in Digital Terrain Models of Europa

2021 ◽  
Vol 13 (24) ◽  
pp. 5097
Author(s):  
Michael T. Bland ◽  
Randolph L. Kirk ◽  
Donna M. Galuszka ◽  
David P. Mayer ◽  
Ross A. Beyer ◽  
...  
Keyword(s):  
Horizontal Resolution ◽  
Data Sets ◽  
Digital Terrain Models ◽  
Matching Accuracy ◽  
Extraterrestrial Life ◽  
Correlation Kernel ◽  
Digital Terrain ◽  
Terrain Models ◽  
Ice Shell ◽  
Pixel Scale

Jupiter’s moon Europa harbors one of the most likely environments for extant extraterrestrial life. Determining whether Europa is truly habitable requires understanding the structure and thickness of its ice shell, including the existence of perched water or brines. Stereo-derived topography from images acquired by NASA Galileo’s Solid State Imager (SSI) of Europa are often used as a constraint on ice shell structure and heat flow, but the uncertainty in such topography has, to date, not been rigorously assessed. To evaluate the current uncertainty in Europa’s topography we generated and compared digital terrain models (DTMs) of Europa from SSI images using both the open-source Ames Stereo Pipeline (ASP) software and the commercial SOCET SET® software. After first describing the criteria for assessing stereo quality in detail, we qualitatively and quantitatively describe both the horizontal resolution and vertical precision of the DTMs. We find that the horizontal resolution of the SOCET SET® DTMs is typically 8–11× the root mean square (RMS) pixel scale of the images, whereas the resolution of the ASP DTMs is 9–13× the maximum pixel scale of the images. We calculate the RMS difference between the ASP and SOCET SET® DTMs as a proxy for the expected vertical precision (EP), which is a function of the matching accuracy and stereo geometry. We consistently find that the matching accuracy is ~0.5 pixels, which is larger than well-established “rules of thumb” that state that the matching accuracy is 0.2–0.3 pixels. The true EP is therefore ~1.7× larger than might otherwise be assumed. In most cases, DTM errors are approximately normally distributed, and errors that are several times the derived EP occur as expected. However, in two DTMs, larger errors (differences) occur and correlate with real topography. These differences primarily result from manual editing of the SOCET SET® DTMs. The product of the DTM error and the resolution is typically 4–8 pixel2 if calculated using the RMS image scale for SOCET SET® DTMs and the maximum images scale for the ASP DTMs, which is consistent with recent work using martian data sets and suggests that the relationship applies more broadly. We evaluate how ASP parameters affect DTM quality and find that using a smaller subpixel refinement kernel results in DTMs with smaller (better) resolution but, in some cases, larger gaps, which are sometimes reduced by increasing the size of the correlation kernel. We conclude that users of ASP should always systematically evaluate the choice of parameters for a given dataset.

scholarly journals High Resolution Digital Terrain Models of Mercury

2020 ◽  
Vol 12 (23) ◽  
pp. 3989
Author(s):  
Moritz Tenthoff ◽  
Kay Wohlfarth ◽  
Christian Wöhler
Keyword(s):  
High Resolution ◽  
Image Resolution ◽  
Evaluation Methodology ◽  
Iteration Step ◽  
Altimeter Data ◽  
Digital Terrain Models ◽  
Reconstruction Procedure ◽  
Laser Altimeter ◽  
Digital Terrain ◽  
Terrain Models

We refined our Shape from Shading (SfS) algorithm, which has previously been used to create digital terrain models (DTMs) of the Lunar and Martian surfaces, to generate high-resolution DTMs of Mercury from MESSENGER imagery. To adapt the reconstruction procedure to the specific conditions of Mercury and the available imagery, we introduced two methodic innovations. First, we extended the SfS algorithm to enable the 3D-reconstruction from image mosaics. Because most mosaic tiles were acquired at different times and under various illumination conditions, the brightness of adjacent tiles may vary. Brightness variations that are not fully captured by the reflectance model may yield discontinuities at tile borders. We found that the relaxation of the constraint for a continuous albedo map improves the topographic results of an extensive region removing discontinuities at tile borders. The second innovation enables the generation of accurate DTMs from images with substantial albedo variations, such as hollows. We employed an iterative procedure that initializes the SfS algorithm with the albedo map that was obtained by the previous iteration step. This approach converges and yields a reasonable albedo map and topography. With these approaches, we generated DTMs of several science targets such as the Rachmaninoff basin, Praxiteles crater, fault lines, and several hollows. To evaluate the results, we compared our DTMs with stereo DTMs and laser altimeter data. In contrast to coarse laser altimetry tracks and stereo algorithms, which tend to be affected by interpolation artifacts, SfS can generate DTMs almost at image resolution. The root mean squared errors (RMSE) at our target sites are below the size of the horizontal image resolution. For some targets, we could achieve an effective resolution of less than 10 m/pixel, which is the best resolution of Mercury to date. We critically discuss the limitations of the evaluation methodology.

scholarly journals Nationwide Digital Terrain Models for Topographic Depression Modelling in Detection of Flood Detention Areas

Water ◽  
2014 ◽  
Vol 6 (2) ◽  
pp. 271-300 ◽  
Author(s):  
Jenni-Mari Vesakoski ◽  
Petteri Alho ◽  
Juha Hyyppä ◽  
Markus Holopainen ◽  
Claude Flener ◽  
...  
Keyword(s):  
Digital Terrain Models ◽  
Digital Terrain ◽  
Terrain Models
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