About Rapid Response Imagery

All images available on the Rapid Response site including through the Web Mapping Service and the State of the Earth are available freely and may be reproduced for any purpose. No registration for LANCE is required. It would be appreciated if user would attach the Acknowledgement and, if possible, include a link to http://earthdata.nasa.gov/data/nrt-data/rapid-response/.

In order to meet the 3-hour latency requirement, the images available are generated using expedited L0 data and predicted attitude and ephemeris data. In some instances, notably for MODIS data, the production rules for the use of ancillary data have been relaxed compared to the science quality data processing systems. In some cases, significant differences exist between the near-real time LANCE products and the science-quality products. The user should be aware that none of the data products available through LANCE can be regarded as science quality and the user should make use of the data with caution and should not apply the data for quantitative science analyses. Nonetheless, all LANCE products have been reviewed by members of the instrument Science Teams and have been approved for applications purposes.

Originally, the Rapid Response system was developed to generate user-specified, geo-referenced MODIS Subsets and MODIS Near Real Time (Orbit Swath) Images. Since there is a substantial user base for these products, they are incorporated into the present system that is part of the larger LANCE system. The principal MODIS products are true and false color images generated using a special corrected reflectance algorithm designed to provide natural looking imagery. The algorithm is a derivative of the land surface reflectance (MxD09) algorithm used in the MODIS science-quality data processing system from which gross atmospheric effects such as Rayleigh scattering have been removed for the MODIS Bands 1-7. In clear atmospheric conditions the two algorithms generate very similar results but they depart in the presence of aerosols. The system makes use of the standard MODIS fire product (MxD14) but the results are subject to the same caution that is given in the paragraph above.

Coincident with the inclusion of the Rapid Response system in the broader LANCE system, a Web Mapping Service and a Google-style State of the Earth display were added that is described in About Displays. Further, the number of data products was significantly expanded to include approximately 40 image products for MODIS, AIRS, and OMI. These products are generated by the individual LANCE elements as part of the near-real time data processing. The intended purpose of these products is to support the end users in the monitoring and analysis of a variety of natural and man-made hazards and disasters. Based upon discussion with the end users and members of the science team, 14 hazards/disaster categories were established for which certain LANCE products will potentially illustrate the phenomena. The categories and the associated data products are shown in the Hazards and Disasters Matrix. The approach that has been taken is to include data products even if they will support analyses only for some cases. Links are provided in this matrix to brief descriptions of the products which include, for some products, quantitative color tables. In some instances these color tables have been modified from those used in the science data processing systems to expedite the inter-comparisons between multiple data sets from different instruments.

In addition to the space-borne products, three data sets have been added to facilitate analyses. The coastlines/administrative boundaries and the population density data are included courtesy of the NASA Socioeconomic Data and Applications Center (SEDAC). Note that the color table for the latter has been modified to facilitate comparison with the MODIS true color data. A land water mask (Ref) has been included to expedite examination of flood conditions particularly in associations with rivers.