Proc. SPIE. 6749, Remote Sensing for Environmental Monitoring, GIS Applications, and Geology VII
KEYWORDS: Data modeling, Satellites, Geographic information systems, Meteorology, Data centers, Earth's atmosphere, Atmospheric monitoring, Atmospheric particles, Atmospheric modeling, Standards development
Historically the atmospheric and meteorological communities are separate worlds with their own data formats and tools
for data handling making sharing of data difficult and cumbersome. On the other hand, these information sources are
becoming increasingly of interest outside these communities because of the continuously improving spatial and temporal
resolution of e.g. model and satellite data and the interest in historical datasets. New user communities that use
geographically based datasets in a cross-domain manner are emerging. This development is supported by the progress
made in Geographical Information System (GIS) software. The current GIS software is not yet ready for the wealth of
atmospheric data, although the faint outlines of new generation software are already visible: support of HDF, NetCDF
and an increasing understanding of temporal issues are only a few of the hints.
The Earth Science (ES) community has two major IT related concerns: Modeling, which requires vast amounts of
computational resources, and exploration and production of large shared data sets. Both can be accomplishable by Grid
infrastructure. Grid or Grid computing is a metaphor name for making computer power as easy to access as an electric
power Grid). Different Grid middleware software solutions exist and are being developed. DEGREE (Dissemination and
Exploitation of Grids in Earth sciencE) aims to disseminate and promote uptake of Grid in ES and to create a bridge
between ES and Grid communities to ensure the next Grid generation will integrate ES application requirements in the
middleware and services. In order to achieve this, DEGREE will: identify key ES requirements, disseminate ES
application requirements to Grid projects, evaluate Grid middleware tools and standards regarding ES requirements and
provide feedbacks to Grid developers. In order to convey requirements to the Grid community, test suite specifications
are developed. A test suite specification consists of documentation and an application suitable for testing, including the
data needed. Eight test suite specifications are developed and made available by DEGREE for Grid middleware
developers. Results will be used to support the development of the ES Grid vision.
The OMI instrument that flies on the EOS Aura mission was launched in July 2004. OMI is a UV-VIS imaging
spectrometer that measures in the 270 - 500 nm wavelength range. OMI provides daily global coverage with high
spatial resolution. Every orbit of 100 minutes OMI generates about 0.5 GB of Level 0 data and 1.2 GB of Level 1 data.
About half of the Level 1 data consists of in-flight calibration measurements. These data rates make it necessary to
automate the process of in-flight calibration. For that purpose two facilities have been developed at KNMI in the
Netherlands: the OMI Dutch Processing System (ODPS) and the Trend Monitoring and In-flight Calibration Facility
(TMCF). A description of these systems is provided with emphasis on the use for radiometric, spectral and detector
calibration and characterization.
With the advance of detector technology and the need for higher spatial resolution, data rates will become even higher
for future missions. To make effective use of automated systems like the TMCF, it is of paramount importance to
integrate the instrument operations concept, the information contained in the Level 1 (meta-)data products and the inflight
calibration software and system databases. In this way a robust but also flexible end-to-end system can be
developed that serves the needs of the calibration staff, the scientific data users and the processing staff. The way this
has been implemented for OMI may serve as an example of a cost-effective and user friendly solution for future
missions. The basic system requirements for in-flight calibration are discussed and examples are given how these
requirements have been implemented for OMI. Special attention is paid to the aspect of supporting the Level 0 - 1 processing with timely and accurate calibration constants.