Remote Sensing Swath Data Content Standard
Date of Proposal
September 23, 1997
Type of Standard
Content standard for remote sensing swath data
National Aeronautics and Space Administration (NASA) Point of Contact: Candace Carlisle, NASA Goddard Space Flight Center, Code 505, Greenbelt, MD 20771. Phone: (301) 614-5186
The primary objective of this proposed standard is to define the content for remote sensing swath data (subsequently called the swath data model), thereby providing a solid basis from which to develop interoperable data formats for this common form of remote sensing data. The data model shall define the minimal content requirements for a swath and the relationships among its individual components. It shall also discuss the treatment of optional supporting information within the swath model.
As stated in Executive Order 12906, dated April 13, 1994, the FGDC shall coordinate the Federal Government's development of the National Spatial Data Infrastructure (NSDI). The Executive Order is intended to strengthen and enhance the general policies described in OMB Circulars A-16 and A-119. The swath data model for remote sensing supports the development of the NSDI by providing a common framework for the organization of a wide range of remotely sensed data. The model will be particularly useful for data from scanning, profiling, staring, or push-broom type remote sensing instruments, whether they be ground based, shipboard, airborne, or spaceborne.
The Committee on Earth Observing Satellites (CEOS), an international standards body, has
endorsed the development of data models for remotely sensed swath data through its Working
Group on Information Systems and Services (WGISS) Data Subgroup.
In order to facilitate interoperability among agencies with remote sensing data holdings and member agencies of international remote sensing groups, participants must first be able to exchange information. Ideally, data from one organization should be easily useable by other organizations performing similar work. In practice, however, each organization has developed its own methods of encoding data that are generally not particularly compatible with those developed by other organizations. The unfortunate results are that data are generally not easily shared among these groups and that researchers who wish to use data from multiple sources find the task of reconciling the data particularly daunting.
Clearly, it is in the interest of the entire remote sensing community that there be a common data encoding mechanism in use by many organizations. Before such an encoding mechanism can become widely accepted, however, each party must share a common conceptual model of the data in question. This is exactly the purpose of the swath data model or content standard. It will provide a common conceptual framework, within which the sharing of remote sensing swath data will become possible.
Data standardization and modeling are major research issues within the Earth Observing System Data and Information System (EOSDIS). The Earth Science Data and Information System (ESDIS) Project is responsible for EOSDIS and has already sponsored much preliminary research into these issues for remote sensing applications. Some early results of the research are presented in EOSDIS Version 0 FY92 Data Structures Report, an internal ESDIS report. Those early results have been further developed into data standards for the EOSDIS Core System (ECS) through soliciting input and comments from scientists around the world and from EOSDIS's Data Model Working Group. As one of the efforts to publicize the EOSDIS data standards and solicit comments, NASA has sponsored a software vendor workshop on EOSDIS data standards in September, 1997. The proposed FGDC content standard for remotely sensed swath data will be based on the ECS swath data model.
The proposed standard will be based on the NASA EOSDIS' data model for remote sensing swath data. The NASA model specifies the minimal content requirements for a swath and the relationships among its individual components. Based on the model, the ESDIS project has developed an encoding mechanism and a set of software tools for EOSDIS. Although these tools are related to the proposed content standard, the standard in no way depends upon them. In fact, it is the tools that rely on the existing EOSDIS data model.
The Spatial Data Transfer Standard (SDTS) addresses the transfer of geospatial data among computer systems. The Raster Profile of SDTS is remotely related to the proposed swath standard because the Raster Profile can be used to transfer remote sensing data. However, the SDTS Raster Profile is a transfer standard, while the proposed swath standard is a content standard. So it is likely that the SDTS Raster Profile can be used to transfer remote sensing swath data, but there is no overlap between the standards because they speak to different aspects of data standardization as per the FGDC Standards Reference Model.
No other current FGDC, national, or international standard addresses remote sensing swath data models.
Development and Completion Schedule
Execution of the timeline below will begin immediately following approval of this proposal.
- Set up review committee - within 4 weeks after approval of proposal.
- Produce working draft of standard - within 6-8 weeks after committee impaneled.
- Conduct committee review - during 4-6 weeks after completion of working draft.
- Revise working draft - within 2 weeks after receipt of committee comments.
- Submit draft to SWG - within 2 weeks of final committee approval. The following steps will take place according to the timing specified by the FGDC review process.
- Review revised draft (SWG).
- Produce revised draft for public review (NASA/ESDIS).
- Conduct public review (FGDC).
- Respond to public comments (NASA/ESDIS).
- Evaluate response to public comments (SWG).
- Approve standard for endorsement (SWG).
- Endorse standard (FGDC).
NASA/GSFC's ESDIS Project will fund this project to develop the content standard for swath data.
NASA, through its Mission to Planet Earth, is already bringing together many diverse groups within the remote sensing community. Through the continuing data standards work done for ESDIS, NASA has gained considerable insight into the requirements of these various groups. Other federal agencies who produce large amounts of remote sensing data, such as NOAA, NIMA, and USGS, as well as the commercial remote sensing community may also participate in the standard development. In addition, under the auspices of the CEOS WGISS, many national and international space agencies will have the opportunity to participate in the development of the swath data model. These agencies play major roles within the remote sensing community.
Other Target Authorization Bodies
This proposed standard is not currently targeted for consideration by any other authorizing bodies. FGDC will serve as the target authorization body. As the FGDC content data standard for remotely sensed swath data, it is expected that this proposed standard could be subsequently authorized by ANSI, ISO, CEOS, or other groups.