GEOMS – Generic Earth Observation Metadata Standard
Encyclopedia
GEOMS - Generic Earth Observation Metadata Standard is a metadata standard used for archiving data from groundbased networks, like the NDACC, and for using this kind of data for the validation of NASA and ESA satellite data.

Introduction

The Generic Earth Observation Metadata Standard (GEOMS) outlines the metadata and data structure requirements developed to facilitate the use of geophysical datasets by improving their portability and accessibility, and by making their contents self-describing. This approach was originally selected to deal with atmospheric and oceanographic datasets, but has been recently expanded to support all measurements from Earth observation
Earth observation
Earth observation is the gathering of information about planet Earth’s physical, chemical and biological systems. It is used to monitor and assess the status of, and changes in, the natural environment and the built environment. In recent years, Earth observation has become technologically more and...

 instruments. The definitions have been carefully chosen to allow applicability to other scientific endeavors. GEOMS metadata and data structure requirements may be applied to any project where data are to be exchanged.

Motivation

For geophysical validation, independent observations are performed by a large number of in-situ, remote sensing, and satellite instruments for comparison with satellite based geophysical data products. To enhance the usability of the diverse correlative datasets collected for the EOS-Aura validation program and the Envisat calibration and validation campaign (Cal/Val), metadata definitions, covering a broad range of instrument types and geophysical parameters have been established. In support of these efforts, relational databases have been designed to store the metadata and to allow extensive quality assurance (QA) and quality control (QC) of the submitted files, while enabling easy data mining and retrieval of selected datasets. This development was initiated in 1998 through the European Commission (EC) project COSE, Compilation of atmospheric Observations in support of Satellite measurements over Europe, and extended in collaboration with ESA, NASA, principal investigators (PI) of the Envisat and Aura validation campaign, and selected PIs from NDACC, for the implementation of a uniform data exchange standard.

Application

The current GEOMS guidelines describe the standard metadata definitions adopted for the correlative, experimental and model data archived for the EOS-Aura validation program, the Envisat calibration and validation efforts, data from NDACC, and the GECA project, which supports existing and future ESA calibration and validation programs.

The first application for earlier versions of GEOMS was the definition of metadata requirements for the calibration and validation activities of the Advanced Along Track Scanning Radiometer (AATSR
AATSR
The Advanced Along Track Scanning Radiometer is one of the Announcement of Opportunity instruments on board the European Space Agency 's Envisat satellite....

), the Global Ozone Monitoring by Occultation of Stars (GOMOS), the MEdium Resolution Imaging Spectrometer (MERIS
MERIS
MEdium Resolution Imaging Spectrometer is one of the main instruments on board the European Space Agency 's Envisat platform.This instrument is composed of five cameras disposed side by side, each equipped with a pushbroom spectrometer. These spectrometers use two-dimensional CCDs...

), the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY
SCIAMACHY
SCIAMACHY is one of ten instruments aboard of ESA's ENVIronmental SATellite, ENVISAT....

) sensors flying on the European Space Agency (ESA) Envisat platform. These metadata requirements are as well applied to the validation program of the National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) Aura mission carrying the High Resolution Dynamic Limb Sounder (HIRDLS), the Microwave Limb Sounder (MLS
MLS
- Organizations :* Major League Soccer, the highest level professional soccer league in the United States and Canada* Michigan Lutheran Seminary, a preparatory high-school in Saginaw, Michigan- Commerce :...

), the Ozone Monitoring Experiment (OMI
Omi
was an ancient Japanese hereditary title denoting rank and political standing that, along with muraji, was reserved for the most powerful clans during the Kofun period...

) and the Tropospheric Emission Spectrometer (TES
TES
Tes may refer to:* Tés, a village in Hungary* Tes River, a river in Mongolia* Tes, Uvs, a district in Mongolia's Uvs Province* Tes, Zavkhan, a district in Mongolia's Zavkhan Province* Teş, a village in Brestovăţ Commune, Timiş County, Romania...

) atmospheric instruments. The scope of GEOMS has been broadened to NASA A-train satellite instruments, to data from the Network for the Detection of Atmospheric Composition Change (NDACC) and additional ESA Earth observation missions. The latter are supported by the Generic Environment for Calibration/Validation Analysis (GECA) project.

Supported Instruments

As of summer 2011 the GEOMS format has been completely defined via templates for the following instrument data:
  • OMI - Ozone Monitoring Instrument (selected datasets)
  • LIDAR - Light Detection And Ranging
  • MWR - Microwave Radiometer
  • FTIR - Fourier Transform Infrared Spectroscopy
  • Radio occultation
    Radio occultation
    Radio occultation is a remote sensing technique used for measuring the physical properties of a planetary atmosphere. It relies on the detection of a change in a radio signal as it passes through the planet's atmosphere i.e. as it is occulted by the atmosphere. When electromagnetic radiation...

     (RO) (selected datasets)
  • UVVIS.DOAS - UV/Vis Differential Optical Absorption Spectroscopy
  • Sondes (selected datasets)
  • Buoys (selected datasets)


For more details please go to GEOMS.

Implementation

In recent years, the Hierarchical Data Format
Hierarchical Data Format
Hierarchical Data Format is the name of a set of file formats and libraries designed to store and organize large amounts of numerical data...

  has become the de-facto satellite data exchange format for the ESA and the NASA Earth observation missions. HDF
HDF
HDF may refer to:* Hadfield railway station , in Derbyshire, England* Heringsdorf Airport, , near Garz on the island of Usedom, Germany...

 was originally developed by National Center for Supercomputing Application (NCSA
NCSA
NCSA may refer to:*National Center for Supercomputing Applications**NCSA HTTPd, an early webserver developed at this center*University of North Carolina School of the Arts*National Cyber Security Alliance...

) and is currently supported by the non-profit HDF Group. Next to HDF, another hierarchical data format, netCDF
NetCDF
NetCDF is a set of software libraries and self-describing, machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data. The project homepage is hosted by the Unidata program at the University Corporation for Atmospheric Research...

, is extensively used in Earth observation. The netCDF format is maintained by Unidata. To facilitate the validation of space borne measurements by correlative data from heterogeneous sources, the use of a common file format becomes a necessity. The metadata guidelines defined in this document are implemented using the HDF4, HDF5 or netCDF file formats, but are not limited to these formats. Special care must be given to the submission of files to GEOMS supporting data centers. Some data centers may not have native support to all discussed data formats.

Members

Currently, the GEOMS group consists of representatives of NASA, ESA, the NDACC and related universities and organizations. The GEOMS group invites interested persons to subscribe to the GEOMS email list as outlined in GEOMS.

See also

More information on GEOMS can be found at the current GEOMS host website at NASA/GSFC: http://avdc.gsfc.nasa.gov/GEOMS/ or by accessing the GEOMS document.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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