Regional Morphometric and Geomorphologic Mapping of Martian Landforms

Computers & GeosciencesComputers & Geosciences, Volume 45, August 2012, Pages 190–198

Radu Dan Capitan and Marco J. Van De Wiel

“Initial mapping of the Martian surface, based on stratigraphic markers identified from Viking imagery, resulted in the demarcation of broad planetary scale geological zones. Recent advances in image resolution have established the presence of many smaller surface elements superposed on the older geological zones, thereby indicating younger surface morphologies that are in contradiction with the older mapping. Moreover, the stratigraphic mapping technique is subjective and relatively cumbersome because of its reliance on visual interpretation of images.

“In this paper a new analytical technique is developed which uses morphometric analysis of the Martian elevation map (MOLA data) to automate delineation and mapping of landforms at the regional scale. The analysis relies on altitude, local relief and local watershed clustering to delineate the landforms, and applies statistical clustering to identify structures with similar properties.

“As a case study, the technique is applied to Atlantis and Gorgonum basins. Comparison of the delineated features with landforms visible on high-resolution THEMIS images illustrates the accuracy of the morphometric technique in delineating and classifying surface structures, and also permits interpretation of the origin and evolution of the landforms. Our results also show that morphometric data and morphologic evaluation can be combined into a single interpretation of the distribution of surface patterns. A new geomorphological map of the study area is produced and contrasted with the existing stratigraphic map.”

Citizen Scientists Map the Transit of Venus

Esri logoEsri Builds Astronomy Observations Map Application

Working with Astronomers Without Borders, GIS software company Esri has built a Transit of Venus web map application that instantaneously displays data from amateur astronomers. Using a free smartphone application, these citizen scientists from around the world will capture their observations of the transit of Venus in early June and have their timing measurements immediately published on a map on esri.com.

“The Astronomers Without Borders relationship with Esri is fantastic,” said Mike Simmons, president of the nonprofit organization. “These technologies make it possible for everyone to take part in important astronomical events.”

Smartphone app.

Smartphone app.

The Esri Transit of Venus web map application, running on ArcGIS for Server, will work in coordination with the iPhone and Android Transit of Venus applications. This web application will show the following:

  • Where on earth the transit is visible and at what times
  • Tweets, pictures, and videos about the transit
  • Points of observations from the phone application with recorded and predicted times
  • An animation on what the transit looks like on the sun and which side of earth can view it

On June 5 or 6, 2012, depending on one’s location, Venus will pass between the earth and the sun. Through telescopes, professional and amateur astronomers will see Venus as a small, round dot moving across the sun. Since the eighteenth century, astronomers’ measurements of this rare event have been used to calculate the distance between the earth and the sun.

With thousands of people projected to participate in the 2012 Transit of Venus project, this may well be one of the largest crowd sourced mapping projects to date. The transit recordings will first be sent to the project center in the Netherlands and a few seconds later to Esri in Redlands, California. Anyone can add their impressions of the transit via Twitter, Flickr, and YouTube, and these social media items will be displayed on the Transit of Venus map.

Follow this Transit of Venus project as it’s happening on June 5 at tov2012.esri.com.

[Source: Esri press release]

Spatial Analysis of Terrain in Virtual Reality

IEEE VR Workshop 2012

Rolf Westerteiger, Andreas Gerndt, Bernd Hamann, and Hans Hagen

“We extend an existing Virtual Reality terrain visualization framework to support spatial analysis tasks for geoscientific purposes. Interactive measurement of height profiles is used as an example application to demonstrate the efficacy of the approach. In this application, virtual reality technology enables superior perception of profile line localization with respect to terrain features.”

Fault network on Mars next to Valles Marineris

Fault network on Mars next to Valles Marineris

An Extensible Simulation Environment and Movement Metrics for Testing Walking Behavior in Agent-based Models

Computers, Environment and Urban SystemsComputers, Environment and Urban Systems, Available online 6 August 2011

Paul M. Torrens, Atsushi Nara, Xun Li, Haojie Zhu, William A. Griffin, and Scott B. Brown

“Highlights:

  • We present a novel framework for simulating pedestrians and metrics for evaluating movement.
  • Our approach can be applied across application scenarios, cities, and scales.
  • We prove its usefulness in studying a range of movement scenarios at different scales.

“Human movement is a significant ingredient of many social, environmental, and technical systems, yet the importance of movement is often discounted in considering systems’ complexity. Movement is commonly abstracted in agent-based modeling (which is perhaps the methodological vehicle for modeling complex systems), despite the influence of movement upon information exchange and adaptation in a system. In particular, agent-based models of urban pedestrians often treat movement in proxy form at the expense of faithfully treating movement behavior with realistic agency. There exists little consensus about which method is appropriate for representing movement in agent-based schemes. In this paper, we examine popularly-used methods to drive movement in agent-based models, first by introducing a methodology that can flexibly handle many representations of movement at many different scales and second, introducing a suite of tools to benchmark agent movement between models and against real-world trajectory data. We find that most popular movement schemes do a relatively poor job of representing movement, but that some schemes may well be “good enough” for some applications. We also discuss potential avenues for improving the representation of movement in agent-based frameworks.”

New USGS Web Service Helps ArcGIS Users Study the Planets

A revised web page with new tools enabling researchers to link planetary features and names directly to programs such as ArcGIS and GoogleEarth has been unveiled, greatly simplifying the work of standardizing terminology and locations of planetary features throughout the solar system.

This new “web feature service, which links the planetary database to the end-user’s program, is part of a comprehensive renovation of the Gazetteer of Planetary Nomenclature website. This website, run by the U.S. Geological Survey’s Astrogeology Science Center, is the official site for accessing the current and complete list of International Astronomical Union approved names for rings, satellites, and features on the surfaces of planets other than Earth.

Once a user’s computer-mapping, or Geographic Information Systems program, is linked, the user can explore the database using a variety of visualization tools and detailed searches.  The service ensures that updates, refinements, and additions to the planetary database are automatically streamed to the user, encouraging the consistent use of IAU approved planetary names. A web map service also allows users to link to and explore planetary maps hosted by the USGS.  The web feature and map services both adhere to Open Geospatial Consortium standards.

The USGS runs this website to assist planetary scientists during the course of new missions. “We help scientists obtain IAU approved names in order to ensure that planetary features of high scientific interest, such as craters, mountains, and channels are officially named and described,” said Jennifer Blue, planetary nomenclature expert with the Astrogeology Science Center.

The new “web feature service” has also precipitated the redesign of the website’s user interface. “The technical requirements of implementing the web feature service provided a unique opportunity to also make visual improvements to the Gazetteer of Planetary Nomenclature website,” said USGS web-developer Ryan Raub.

The new website is intended to enhance the user’s visual experience and provide intuitive and efficient exploration of the planetary nomenclature database. It provides an interactive homepage, complete with rotating planets, where users can quickly select a planet or body of interest. International Astronomical Union approved names are displayed as annotated points or areas on an image of the planet, where users can pan to different regions or zoom for increased detail.  With a few clicks, users can display detailed information about surface features such as a size and location as well as what the name means.

USGS web-developer Mark Bailen notes the new website benefits scientists and enthusiasts alike. “The new ‘target chooser’ provides a fun way to explore the planets while revealing valuable information about the Solar System,” said Bailen.

The web feature and map services are the first of several improvements that will take place to the Gazetteer of Planetary Nomenclature over the coming months and years.  To explore the new website and access its new web feature and map services, please visit Planetary Nomenclature website. For more information on linking to the services, visit the Astrodocs Webservices website.

The mission of the USGS Astrogeology Science Center is to serve the Nation, the international planetary science community, and the general public’s pursuit of new knowledge of our Solar System. The Science Center’s vision is to be a national resource for the integration of planetary geosciences, cartography, and remote sensing. As explorers and surveyors, with a unique heritage of proven expertise and international leadership, USGS astrogeologists enable the ongoing successful investigation of the Solar System for humankind. For more information, visit http://astrogeology.usgs.gov.

[Source: USGS press release]

Assessment of Planetary Geologic Mapping Techniques for Mars using Terrestrial Analogs: The SP Mountain Area of the San Francisco Volcanic Field, Arizona

Planetary and Space Science, Volume 57, Issues 5-6, May 2009, Pages 510-532

Kenneth L. Tanaka, James A. Skinner Jr., Larry S. Crumpler, James M. Dohm

“We photogeologically mapped the SP Mountain region of the San Francisco Volcanic Field in northern Arizona, USA to evaluate and improve the fidelity of approaches used in geologic mapping of Mars. This test site, which was previously mapped in the field, is chiefly composed of Late Cenozoic cinder cones, lava flows, and alluvium perched on Permian limestone of the Kaibab Formation. Faulting and folding has deformed the older rocks and some of the volcanic materials, and fluvial erosion has carved drainage systems and deposited alluvium. These geologic materials and their formational and modificational histories are similar to those for regions of the Martian surface. We independently prepared four geologic maps using topographic and image data at resolutions that mimic those that are commonly used to map the geology of Mars (where consideration was included for the fact that Martian features such as lava flows are commonly much larger than their terrestrial counterparts). We primarily based our map units and stratigraphic relations on geomorphology, color contrasts, and cross-cutting relationships. Afterward, we compared our results with previously published field-based mapping results, including detailed analyses of the stratigraphy and of the spatial overlap and proximity of the field-based vs. remote-based (photogeologic) map units, contacts, and structures. Results of these analyses provide insights into how to optimize the photogeologic mapping of Mars (and, by extension, other remotely observed planetary surfaces). We recommend the following: (1) photogeologic mapping as an excellent approach to recovering the general geology of a region, along with examination of local, high-resolution datasets to gain insights into the complexity of the geology at outcrop scales; (2) delineating volcanic vents and lava-flow sequences conservatively and understanding that flow abutment and flow overlap are difficult to distinguish in remote data sets; (3) taking care to understand that surficial materials (such as alluvium and volcanic ash deposits) are likely to be under-mapped yet are important because they obscure underlying units and contacts; (4) where possible, mapping multiple contact and structure types based on their varying certainty and exposure that reflect the perceived accuracy of the linework; (5) reviewing the regional context and searching for evidence of geologic activity that may have affected the map area yet for which evidence within the map area may be absent; and (6) for multi-authored maps, collectively analyzing the mapping relations, approaches, and methods throughout the duration of the mapping project with the objective of achieving a solid, harmonious product.”

Mission Architecture Decision Support System for Robotic Lunar Exploration

Planetary and Space Science, Volume 57, Issue 12, October 2009, Pages 1434-1445

P. Weiss and K.L. Yung

“It is common practice in the landing site decision process for planetary or lunar exploration to limit the choice of sites to locations that strictly meet the technical and safety requirements of the lander. The science objective is ultimately implemented within the operational requirements of the mission strategy.

“In this paper, we present a study that derives the technical requirements of the landing strategy by considering proposed landing sites. The study reviewed the objectives of the future robotic exploration of the Moon and proposed targets from the Apollo era to our time. Three types of strategies are defined, namely, rover missions, immobile landing stations, and impacting probes. The capabilities and restrictions of each system are taken into account and compared to the science objectives of the proposed landing sites. A Geographic Information System (GIS) with lunar datasets was developed and the methodology was implemented. The study concludes with a description of the resulting mission scenarios that were assigned to the targets. The technical requirements for each landing system to fulfil these scientific objectives are derived and the feasibility, based on the technological readiness, is discussed.”