By Emily Northup
James Madison University, New York, U.S.
The Atmospheric Science Data Center (ASDC) at NASA Langley Research Center is responsible for the ingestion, archiving, and distribution of NASA Earth Science data in the areas of radiation budget, clouds, aerosols, and tropospheric chemistry. The ASDC specializes in atmospheric data that is important to understanding the causes and processes of global climate change and the consequences of human activities on the climate.
In 2012, the ASDC facilitated the development of the first-ever strategic plan intended for fiscal year 2013 and beyond [4]. The 2013 Strategic Plan serves as a mission-focused plan with six defined goals.
The first goal says: The ASDC will strive to expand beyond our existing customer base by increasing accessibility to a broader, worldwide market; through the use of innovative technologies, the ASDC will enhance data access capabilities and develop plans to share data with new user communities.
Pursuant of this goal, the ASDC is piloting the use of new technologies to implement for enhanced data access capabilities for observing Earth’s climate. The technologies being explored and piloted include Geographic Information System (GIS) technologies, which can be leveraged for planning, response, and awareness of climate change. The purpose of the pilot is to increase discoverability of and accessibility to the useful big science data held at the NASA’s ASDC. The growing GIS community can access ASDC data holdings in order to gain a better understanding of climate change and to coordinate responses.
The GIS user community works with tools and applications that require different formats and services for data than what are currently served at the ASDC. Through the use of the existing Enterprise License Agreement (ELA) between Esri and NASA for software, the ASDC can provide data in GIS formats and Open Geospatial Consortium (OGC) compliant services. The OGC compliant services will include a Web Mapping Service (WMS), Web Coverage Service (WCS), and Web Processing Service (WPS). The WMS provides basic image browse capabilities, which grants users the ability to quickly view data of interest over the Web before directly accessing it. The WCS provides the actual data instead of an image browse, enabling the user to run the data through tools and applications on their machine [3]. The WPS provides users with a way to access and run processes on data located on a GIS server and get a resulting dataset in return.
Figure 1 represents the process necessary for implementing the tasks stated in the ASDC pilot for GIS technologies, and shows the process for using data from these satellite programs in Esri to create OGC compliant services.
Figure 1. Diagram of the process for using ASDC data in Esri to create OGC compliant services. Image Credit: Emily Northup & Matthew Tisdale.
The Atmospheric Science Data Center houses data in Earth science-related areas from several of NASA Langley’s satellite programs, such as Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), the Stratospheric and Gas Experiment (SAGE) missions, and the Clouds and the Earth’s Radiant Energy System (CERES) program.
Step 1 in the Figure 1 diagram shows data being archived at the ASDC. Step 2 is the publisher’s machine using ArcGIS for Desktop, to publish the map built based on the data used. Step 3 is the ArcGIS for Server machine being set to reference the ASDC data. ArcGIS for Server provides integrated server-based GIS through applications and services for spatial data management, visualization, and spatial analysis. The ASDC data and the ArcGIS for Server reside on Linux machines running SAMBA. This allows the publisher’s machine and the server to reference all of the same data so that is it not copied when the map is published. Step 4 is a Web Map Service (WMS) generated by ArcGIS for Server after publishing. Step 5 is a Web Coverage Service (WCS) which is also generated by ArcGIS after publishing. The WCS defines Web-based retrieval of coverages – that is, digital geospatial information representing the space and time varying phenomena. Step 6 shows utilizing commercial GIS applications, such as ArcGIS for Desktop, to test the WMS and WCS to ensure the data integrity is maintained as well as the speed and reliability of the services. Lastly, Step 7 shows utilizing open source GIS applications, such as NASA World Wind and Quantum GIS, to test the services and ensure that they respond the same as the commercial GIS applications.
Figure 2 shows the cloud coverage during Hurricane Sandy approaching the U.S. East Coast extending from Florida to Massachusetts on Oct. 28, 2012. Outlined in yellow is MISR data; the MISR instrument is aboard the Terra satellite and produces parameters relevant to the study of wildfire smoke plumes as well as dust plumes and volcanic plumes. The CALIPSO data outlined in purple shows the increased cloud coverage on Oct. 29, 2012, spanning from North Carolina to Pennsylvania. CALIPSO is able to provide new insight into the role that clouds and atmospheric aerosols play in regulating Earth’s weather, climate, and air quality. These data were obtained from the NASA Langley Research Center Atmospheric Science Data Center [2].
This map product is one example of the endless possibilities using ASDC data products in a GIS. The purpose of the ASDC strategic plan and the GIS pilot are parallel in that the goal is increased discoverability and accessibility of useful data products for observing Earth’s climate. Once the pilot is operationalized, the goal is to make a WMS, WCS, and WPS made available to the public. The ASDC is hopeful that by making these files usable in the GIS community, agencies such as the Department of Homeland Security and Department of Defense will find them useful and easy to work with.
Figure 2. Produced by ASDC data, this map shows the track of Hurricane Sandy in 2012 with MISR and CALIPSO data products being highlighted in yellow and purple, respectively. Image Credit: Emily Northup & Matthew Tisdale.
References
[1] Angeli, E., Wagner, J., Lawrick, E., Moore, K., Anderson, M., Soderlund, L., & Brizee, A. (2010, May 5). General format. Retrieved from http://owl.english.purdue.edu/owl/resource/560/01/ [2] Atmospheric Science Data Center. (2013, August 5). Citing ASDC data. Retrieved from https://eosweb.larc.nasa.gov/HPDOCS/datapool/ [3] Baumann, Peter. (2010, October 27). OGC WCS 2.0 interface standard-core. Retrieved from http://www.opengeospatial.org/standards/is [4] National Aeronautics and Space Administration. (2012). Atmospheric Science Data Center strategic plan. Retrieved on August 5, 2013.