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Data Systems

The NPP data systems are responsible for storing, and processing data from the instruments on the NPP satellite. They take the raw data sent from the instruments, and run advanced algorithms to create high level data products. Each instrument will provide measurements in Raw Data Record (RDR) form that will be used to create three different types of data products for each instrument. Sensor Data Records (SDRs), Environmental Data Records (EDRs), and Climate Data Records (CDRs). A description of each of the products can be seen in the Data Products section.

As NPP development continues, more data systems will be brought online. As soon as the responsibilities and specifications of these system are available, links will be made available here. Currently, only NPP1 of the NPP simulation systems is operational.

Simulation Systems

NPP has created its own systems for data product creation and simulations.
These will be available to the NPP science team and will provide access to MODIS data, as well as simulated VIIRS data. Currently there is only one system online, NPP-1. Another one is planned for further simulations.

IDPS

The Interface Data Processing Segment (IDPS) receives raw instrument data and telemetry from ground stations supporting the NPP mission. The IDPS removes Raw Data Records (RDRs) from the data stream, then processes RDRs into Sensor Data Records (SDRs) and ultimately Environmental Data Records (EDRs). During the NPP era, the IDPS will supply RDRs, SDRs and EDRs to two meteorological Centrals for evaluation or use in environmental applications. These two Centrals are National Environmental Satellite, Data, and Information Service (NESDIS) and the Air Force Weather Agency (AFWA).

The IDPS also transmits RDRs, SDRs, and EDRs to the Archive and Distribution Segment (ADS) for archiving and access/distribution to the broader user community and forwards RDRs to the Science Data Segment (SDS). The SDS will interface with the IDPS installed in the NESDIS facility to establish the necessary data flows.
In addition, the IDPS provides routine instrument calibration and monitors the performance of data processing algorithms employed in the generation of environmental data and products.

SDS

The NPP SDS continues in a state of reorganization pending selection of the key discipline components called Climate Analysis Research Systems.

ADS

The Archive & Distribution Segment (ADS) is to archive all IDPS and SDS products. It will enable the public and the Science Team access to the archived products. Assuming sufficient resources are available, the ADS will support SDS reprocessing to enable retrieval of products (RDRs, SDRs, and EDRs).

Data Products

The NPP operational products, RDRs, SDRs and EDRs, for VIIRS, CrIS, ATMS and OMPS will be produced using the Integrated Data Processing Segment (IDPS) resources. Research algorithm Level 1, Level 2 (CDRs) and higher products will be produced at the Science Data Segment (SDS).

You can download a sample NPP operational product dataset here. This 1.6GB zip file contains sample products, compliant with NPP HDF5 data format specifications, that were produced by IDPS during test activities.

Description of Level 1 Products (SDRs/Level 1B):

VIIRS, CrIS, ATMS and OMPS Sensor Data Records (SDRs) are full resolution sensor data that are time referenced, Earth located, and calibrated by applying the ancillary information, including radiometric and geometric calibration coefficients and geo-referencing parameters such as platform ephemeris. These data are processed to sensor units (e.g., radiances). Calibration, ephemeris, and other ancillary data necessary to convert the sensor data back to sensor raw data (counts) are included.

Description of Level 2 (EDR/CDRs) Products:

The NPP Mission will produce a series of Environmental Data Records (EDRs), which are a subset of the NPOESS EDRs. All 29 NPP EDRs will be produced at the IDPS and a subset of these, and potentially other products, will be produced as Climate Data Records (CDRs) at the SDS. These EDRs and CDRs may have different requirements. In the case of operational products, emphasis will be on generating products with a more rapid data delivery that necessarily involves high-speed availability of ancillary data and high-performance execution of the sensor contractors' state-of-the-art science algorithms for civilian and military applications. For climate research products, the requirement of timeliness can be relaxed, thereby allowing for the implementation of complex algorithms using diverse ancillary data. As understanding of sensor calibration issues and radiative transfer from the Earth and Atmosphere improves, algorithms can be improved, and products can be generated via reprocessing.

CDRs will be produced by the NASA NPP science team, which was selected in mid 2007.

data products
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