[Federal Register Volume 64, Number 26 (Tuesday, February 9, 1999)]
[Notices]
[Pages 6375-6376]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-3048]


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DEPARTMENT OF THE INTERIOR

Geological Survey


Federal Geographic Data Committee (FGDC); Public Comment on the 
Proposal To Develop the ``Content Standard for Digital Geospatial 
Metadata: Extensions for Remote Sensing Metadata'' as a Federal 
Geographic Data Committee Standard

ACTION: Notice; request for comments.

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SUMMARY: The FGDC is soliciting public comments on the proposal to 
develop a ``Content Standard for Digital Geospatial Metadata: 
Extensions for Remote Sensing Metadata.'' If the proposal is approved, 
the standard will be developed following the FGDC standards development 
and approval process and will be considered for adoption by the FGDC.
    In its assigned federal leadership role in the development of the 
National Spatial Data Infrastructure (NSDI), the Committee recognizes 
that FGDC standards must also meet the needs and recognize the views of 
State and local governments, academia, industry, and the public. The 
purpose of this notice is to solicit such views. The FGDC invites the 
community to review the proposal and comment on the objectives, scope, 
approach, and usability of the proposed standard; identify existing 
related standards; and indicate their interest in participating in the 
development of the standard.

DATES: Comments must be received on or before March 19, 1999. Comments 
are accepted at any time however the maintenance organization for this 
proposal has the authority to reject comments received after this date.

CONTACT and ADDRESSES: Comments may be submitted via Internet mail or 
by submitting electronic copy on diskette. Send comments via Internet 
to: www.fgdc.gov">gdc-rsex@www.fgdc.gov. A soft copy version, on a 3.5 x 3.5 diskette 
in WordPerfect 5.0 or 6.0/6.1 format, along with one hardcopy version 
of the comments may be sent to the FGDC Secretariat (attn: Jennifer 
Fox) at U.S. Geological Survey, 590 National Center, 12201 Sunrise 
Valley Drive, Reston, Virginia, 20192.

SUPPLEMENTARY INFORMATION: Following is the complete proposal for the 
``Content Standard for Digital Geospatial Metadata: Extensions for 
Remote Sensing Metadata''.
    Project Title: Content Standard for Digital Geospatial Metadata: 
Extensions for Remote Sensing Metadata.
    Data of Proposal: October 21, 1998.
    Submitting Organization: FGDC Standards Working Group, Imagery 
subgroup (National Aeronautics and Space Administration (NASA)).
    Point of Contact: Benjamin Kobler, NASA Goddard Space Flight 
Center, Mail Code 423, Greenbelt, MD 20771. Phone: 301-614-5231. 
Electronic mail: [email protected].

Objectives

    The purpose of this proposal is to provide extensions to the 
Federal Geographic Data Committee (FGDC) Content Standard for Digital 
Geospatial Metadata (also referred to hereafter as the Metadata Content 
Standard) for metadata describing geospatial data obtained from remote 
sensing. Efforts will be made to make these extentions consistent with 
the ISO metadata standard under development. Adding these extensions 
will provide a way to incorporate the metadata needed for remote 
sensing into the Metadata Content Standard.

Scope

    These extensions will define content standards for metadata not 
defined in the Metadata Content Standard that are needed for describing 
data obtained from remote sensing. They will include metadata 
describing the observing geometry, the sensor, and the method and 
process of deriving geospatial information from raw telemetry. In 
addition, metadata to describe granules, the individual files or images 
that collectively make up a data product, will be defined.

Justification

    Proper use of remote sensing data requires an understanding of how 
those data were obtained. While ground-based data are often compiled 
from existing data sources without change of form or are obtained by 
direct in situ measurement, deriving geospatial data from the 
measurements made by remote sensing instruments is often much less 
direct. To do so may require knowledge of the observing geometry, the 
instrument behavior, and the processing methods and history. In 
addition, remote sensing measurements produce large volumes of data, 
and users typically do not access the entire data set, only selected 
files or frames.
    Information about the viewing geometry and the properties and 
behavior of the instrument in the FGDC Metadata Content Standard is 
limited to the description of the number of points along the raster 
axes. The draft ISO metadata standard also includes solar elevation and 
azimuth angles and the angle of an image to the vertical.

[[Page 6376]]

However, many users need a more detailed viewing geometry: satellite 
orbit or aircraft flight path, platform orientation, and orientation of 
instruments relative to the platform. While the proposed ISO standard 
includes a number of items in the section of spatial data 
representation describing instrumentation not present in the FGDC 
Metadata Content Standard, the only calibration information is whether 
camera calibration information is available. More information on the 
calibration of the instrument, including its dependence on wavelength 
and time, is usually required. A standard description of such metadata 
should be defined.
    Processing of remote sensing data passes through several stages. 
The instrument calibration must be applied to the readings communicated 
by the raw telemetry and the resulting physical meaurements located 
geographically. In some cases, what the instruments measure is not the 
final product; for example, radiation measurements may be used to infer 
temperatures. Maps and grids may be generated from data at individual 
points. Information on the algorithms used for these steps should 
accompany the data. In addition, information about the processing 
itself, such as what stage a given processing represents, or which 
version of processing is represented, is needed. The FGDC Metadata 
Content Standard allows for this information an entry for lineage, 
which the draft ISO standard has expanded this item to an entire 
section on lineage information, but in both cases the content is 
unspecified free text. These extensions will define the specific items 
that are needed in remote sensing metadata.
    The dataset containing results from a remote sensing mission is 
large and heterogeneous. Necessary descriptive metadata may not apply 
to the entire dataset, but only to individual pictures or files. While 
the FGDC Metadata Content Standard has no specific provision for such 
granularity, the informative Appendix F to the ISO draft provides but 
does not define granule-specific metadata. These extensions will define 
the granule-level metadata appropriate to remote sensing.

Benefits

    Adoption of these extensions will broaden the applicability of the 
Metadata Content Standard to include metadata needed to describe 
geospatial data derived from remote sensing. Making this standard 
directly relevant to the remote sensing community will encourage its 
use. There will be less chance that future producers of remote sensing 
data will see the Metadata Content Standard as inapplicable to their 
needs and develop separate standards.

Approach

    Data standardization and modeling are major research issues within 
the Earth Observing System Data and Information System (EOSDIS) 
development process. Results of this research, combined with comments 
from scientists around the world, from the EOSDIS Data Model Working 
Group, and from Earth Science Data and Information System (ESDIS) 
staff, have been developed into metadata for the EOSDIS Core System 
(ECS). There metadata are described in the Proposed ECS Core Metadata 
Standard. This document defines metadata in several areas in the scope 
of the extensions to be developed and will be used as a basis of the 
extensions covering those areas. The Moderate-Resolution Imaging 
Radiometer (MODIS) Level 1A Earth Location: Algorithm Theoretical Basis 
Document has a detailed discussion of the information and process 
required to derive positions in geographical coordinates given 
spacecraft and instrument position and orientation. That discussion 
will serve as the basis for the definition of viewing geometry 
metadata. As the proposed extensions are to be developed following FGDC 
prescriptions, development and adoption is to proceed through the FGDC 
Standards Working Group (SWG) procedures. The Imagery Subgroup will 
develop these extensions; working scientists with whom it is in contact 
will also contribute. Because both metadata and remote sensing 
applications are involved, the Metadata Ad Hoc Working Group should be 
involved at appropriate stages.

Related Standards

    This standard is intended as extended elements of the FGDC Content 
Standard for Digital Geospatial Metadata. It will follow the 
prescriptions of Appendix D of that Standard, which specifies the 
requirements for extended elements. ISO/Technical Committee 211, 
Working Group 3 is developing an international standard for metadata; 
the current draft is ISO/CD 15046-15. When development of that standard 
is complete, it is likely to be considered for adoption by FGDC, 
superseding those parts of the current standard where there is overlap. 
The ISO standard also has a recommended extension methodology, in 
Appendix E. The information there will be used to guide the process of 
development of these extensions to the metadata standard. Extensions to 
the current FGDC standard covering areas in the ISO standard not in the 
FGDC standard will be constructed to be compatible with the ISO 
standard.
    As noted in the section on approach, the ECS Core Metadata 
Standard, which covers many of the areas in the scope of these 
extensions, will be used where relevant as a basis for the FGDC 
codification.

Schedule

    Submission of proposal to FGDC/SWG: November 1998.
    Submission of Working Draft to FGDC/SWG: late 1999.

Resources

    NASA's ESDIS project will fund the effort required to develop these 
FGDC Content Standard for Digital Geospatial Metadata: Extensions for 
Remote Sensing Metadata.

Potential Participants

    Through the Mission to Planet Earth, NASA already involves many 
diverse groups in the remote sensing community. The continuing 
standards work for ESDIS has provided considerable insight into the 
requirements of these groups. Other federal agencies that produce large 
quantities of remote sensing data, such as the National Oceanic and 
Atmospheric Administration, the National Imagery and Mapping Agency, 
and the U.S. Geological Survey, may also participate in development of 
the standard. Contributions will be solicited from the academic remote 
sensing community.

Target Authorization Body

    The proposed extensions are not specifically targeted for 
consideration by any authorizing agency other than FGDC. However, as 
efforts to bring the FGDC standard into consistency with the ISO 
standard proceed, efforts may be made to gain ISO endorsement as well.

    Dated: January 28, 1999.
Richard E. Witmer,
Chief, National Mapping Division.
[FR Doc. 99-3048 Filed 2-8-99; 8:45 am]
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