Speakers: Saadat Anwar, Eric Engle, Scott Dickenshied
by Dana Nourie |
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The Mars Rover gained a lot of attention last year at the 2007 JavaOne Conference, as much of the Rover's controls were done using Java technologies. This year the focus went to an all important mapping system called Java Mission-planning and Analysis for Remote Sensing (JMARS), a Java technology-based geospatial information system developed by the Mars Space Flight Facility at Arizona State University.
JMARS can simultaneously display multiple data sets (such as maps, image footprints, numerical data products, and so forth) collected by instruments on several current and past NASA missions, such as Mars Odyssey, Mars Global Surveyor, Mars Reconnaissance Orbiter, and the up-coming Lunar Reconnaissance Orbiter.
Mars Odyssey's primary science mission took place February 2002 through August 2004, and the orbiter began its extended mission on August 24, 2004. For the first time, the mission mapped the quantity and distribution of chemical elements and minerals that make up the Martian surface. The spacecraft globally mapped many elements, and the maps of hydrogen distribution led scientists to discover vast amounts of water ice in the polar regions buried just beneath the surface. Odyssey recorded the radiation environment in low Mars orbit to determine the radiation-related risk to human explorers who may one day visit Mars.
Mars Global Surveyor arrived at Mars on September 11, 1997, and has contributed a multitude of findings, including signs of past, persistent water such as an ancient delta and currently active water features in the gullies of canyon walls. After nearly a decade of discovery, MGS went silent in November, 2006.
JMARS is a targeting tool for Thermal Emission Imaging System (THEMIS) and High Resolution Imaging Science Experiment (HiRISE), and Geographical Information Systems (GIS) for working with satellite data on a planetary scale. JMARS provides convenient access to terabytes of maps and images from many Mars missions. And it is freely accessible to the Mars science community and the general public.
The main mission of JMARS is to map other worlds, do real science with the data, build services to share the data, and support other missions in doing the same. New data sets are constantly being added to JMARS from all of these missions and instruments as new data is collected and existing data undergoes further processing and analysis.
Currently THEMIS at Arizona State University and HiRISE (MRO) at University of Arizona are using JMARS for targeting for their research. In addition, 5th grade children through college students are using JMARS in the Student Imagine Project.
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Mars Student Imaging Project
NASA and Arizona State University's Mars Education Program is offering students nationwide the opportunity to be involved in authentic Mars research by participating in the Mars Student Imaging Project (MSIP). Teams of students in grades five through college sophomore level have the opportunity to work with scientists, mission planners and educators on the THEMIS team at ASU's Mars Space Flight Facility, to image a site on Mars using the THEMIS visible wavelength camera onboard the Mars Odyssey spacecraft that is currently orbiting Mars every two hours.
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The JMARS user interface consists of two windows: the Layer Manager and the Viewing Window.
The Layer Manager controls the data sets or analysis tools (called layers) that are loaded into the current session of JMARS. Layers can be viewed with varying resolutions and attributes, which are all controlled by parameters in the focus panel associated with each layer. The focus panels can be accessed by clicking on the appropriate tabs at the top of the Layer Manager.
The Viewing Window displays the visual data associated with the open layers in the Layer Manager. The layered approach allows the simultaneous display of more than one layer. The layers, which users can think of as being stacked on top of each other, are drawn in the Viewing Window in bottom-to-top order. The order of the layers and the transparency of each layer can be adjusted to show features which might otherwise be hidden.
The demonstration we watched in this session showed some very impressive details of canyons on Mars. We also saw how you could target a specific area using JMARS, say for a possible landing spot, and then the data is collected from one of the Mars satellites. In addition to obtaining images for the site, data is collected on elevations, composition, and so forth. It takes about a week to receive the data, which can then be viewed in JMARS as high resolution images. JMARS also provides tool tips that reveal data such as elevation and composition.
The following Java technologies are used in JMARS:
- The user interface uses AWT/Swing
- Image processing with Java 2D API
- 3D visualization with Java 3D API
- Serialization and Threading
- Common file formats, codecs, and protocols
The team had to deal with the issue of measuring data in terabytes; a challenge solved by implementing a Graphics2D subclass to handle scale and wrapping. They also had to write their own sorting tables. In addition, they created a framework for working with shape data. And finally, because NASA likes to use obscure file formats, they had to write their own interfaces to handle special file types.
The project is open source, and developers are welcome to work with the software, report bugs, submit patches, and make other contributions.
For more information
see http://jmars.asu.edu/javaone2008
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