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Kenneth L. Edmundson

Publications and source records attributed to Kenneth L. Edmundson.

3 recordsLinked to original sources
USGS2018

Image mosaic and topographic maps of Mercury

Map Descriptions Sheet 1 : This image mosaic is based on observations acquired by the Mercury Dual Imaging System (MDIS; Hawkins and others, 2009), an instrument on the National Aeronautics and Space Agency (NASA) MErcury Surface, Space ENvironment, Geochemistry, and Ranging (MESSENGER) spacecraft (Solomon and others, 2007). The Mercator projection is used between latitudes ±57°, with a central meridian at 0° longitude and latitude equal to the nominal scale at 0°. The polar stereographic projection is used for the regions north of the +55° parallel and south of the –55° parallel, with a central meridian set for both at 0° and a latitude of true scale at +90° and –90°, respectively. All features greater than 100 km in diameter or length were included unless they were not visible at the printed map scale. Some selected well-known features less than 100 km in diameter or length were also included. For listed references, please open the full PDF. Sheet 2 : This map is based on data acquired by the Mercury Dual Imaging System (MDIS; Hawkins and others, 2009) and Mercury Laser Altimeter (MLA; Cavanaugh and others, 2007) instruments on the National Aeronautics and Space Agency (NASA) MErcury Surface, Space ENvironment, Geochemistry, and Ranging (MESSENGER) spacecraft (Solomon and others, 2007). The topographic shaded-relief maps were generated from the original MDIS- and MLA-based DEMs with a sun angle of 45° from horizontal and a sun azimuth of 270°, as measured clockwise from north, with no vertical exaggeration. The DEM values were then mapped to a global color look-up table, with each color representing a range of 1 km of elevation. The shaded-relief and color files were then merged and scaled to 1:20,000,000 for the Mercator portion and 1:12,157,366 for the two polar stereographic parts with a resolution of 300 pixels per inch. The two projections have a common scale at ±56° latitude. The Mercator projection is used between latitudes ±57°, with a central meridian at 0° longitude and latitude equal to the nominal scale at 0°. The polar stereographic projection is used for the regions north of the +55° parallel and south of the –55° parallel, with a central meridian set for both at 0° and a latitude of true scale at +90° and –90°, respectively. All features greater than 200 km in diameter or length were included unless they were not visible at the printed map scale. Some selected well-known features less than 200 km in diameter or length were also included. Sheet 2 is offered digitally as a layered PDF with two elevation color ramp options—the original printed version and a multicolored ramp developed by the MESSENGER team for their global products. For listed references, please open the full PDF.

Scientific Investigations Map↗
USGS2017

Community tools for cartographic and photogrammetric processing of Mars Express HRSC images

The High Resolution Stereo Camera (HRSC) on the Mars Express orbiter (Neukum et al. 2004) is a multi-line pushbroom scanner that can obtain stereo and color coverage of targets in a single overpass, with pixel scales as small as 10 m at periapsis. Since commencing operations in 2004 it has imaged ~ 77 % of Mars at 20 m/pixel or better. The instrument team uses the Video Image Communication And Retrieval (VICAR) software to produce and archive a range of data products from uncalibrated and radiometrically calibrated images to controlled digital topographic models (DTMs) and orthoimages and regional mosaics of DTM and orthophoto data (Gwinner et al. 2009; 2010b; 2016). Alternatives to this highly effective standard processing pipeline are nevertheless of interest to researchers who do not have access to the full VICAR suite and may wish to make topographic products or perform other (e. g., spectrophotometric) analyses prior to the release of the highest level products. We have therefore developed software to ingest HRSC images and model their geometry in the USGS Integrated Software for Imagers and Spectrometers (ISIS3), which can be used for data preparation, geodetic control, and analysis, and the commercial photogrammetric software SOCET SET (® BAE Systems; Miller and Walker 1993; 1995) which can be used for independent production of DTMs and orthoimages. The initial implementation of this capability utilized the then-current ISIS2 system and the generic pushbroom sensor model of SOCET SET, and was described in the DTM comparison of independent photogrammetric processing by different elements of the HRSC team (Heipke et al. 2007). A major drawback of this prototype was that neither software system then allowed for pushbroom images in which the exposure time changes from line to line. Except at periapsis, HRSC makes such timing changes every few hundred lines to accommodate changes of altitude and velocity in its elliptical orbit. As a result, it was necessary to split observations into blocks of constant exposure time, greatly increasing the effort needed to control the images and collect DTMs. Here, we describe a substantially improved HRSC processing capability that incorporates sensor models with varying line timing in the current ISIS3 system (Sides 2017) and SOCET SET. This enormously reduces the work effort for processing most images and eliminates the artifacts that arose from segmenting them. In addition, the software takes advantage of the continuously evolving capabilities of ISIS3 and the improved image matching module NGATE (Next Generation Automatic Terrain Extraction, incorporating area and feature based algorithms, multi-image and multi-direction matching) of SOCET SET, thus greatly reducing the need for manual editing of DTM errors. We have also developed a procedure for geodetically controlling the images to Mars Orbiter Laser Altimeter (MOLA) data by registering a preliminary stereo topographic model to MOLA by using the point cloud alignment ( pc_align ) function of the NASA Ames Stereo Pipeline (ASP; Moratto et al. 2010). This effectively converts inter-image tiepoints into ground control points in the MOLA coordinate system. The result is improved absolute accuracy and a significant reduction in work effort relative to manual measurement of ground control. The ISIS and ASP software used are freely available; SOCET SET, is a commercial product. By the end of 2017 we expect to have ported our SOCET SET HRSC sensor model to the Community Sensor Model (CSM; Community Sensor Model Working Group 2010; Hare and Kirk 2017) standard utilized by the successor photogrammetric system SOCET GXP that is currently offered by BAE. In early 2018, we are also working with BAE to release the CSM source code under a BSD or MIT open source license.

The International Archives of the Photogrammetry, ↗