Nagg - a Tool to Aggregate and Package JPSS Products

Nagg is a tool for aggregating data granules from existing JPSS files into new files with a different number of granules or different combinations of compatible products.

Nagg is needed to address the flexibility of JPSS products, especially swath products. A swath is a ribbon of data collected as the satellite orbit sweeps across the Earth. As an orbit is continuous, the swath is continuous, wrapping around the Earth over and over again like yarn on a ball. Each swath is snipped into equal size pieces called granules. Each product is distributed in files with a standard number of granules, which may be different between products. Nagg can rearrange the composition of the files to suit the application needs.

For example, VIIRS products are distributed with one granule per file. If an analyst wants to compare MODIS and VIIRS data, nagg can aggregate four VIIRS 86 second granules per file to make the piece of swath similar in size to the MODIS 5 minute data granule.

Another example is OMPS products that are distributed with 160 granules per file. Each file corresponds to one full orbit. Nagg can deaggreate the files into a smaller number of granules per file to suit data analysis tools that process partial orbit.

Nagg can also combine multiple compatible products, including geolocation products, into the same file if desired.

Our poster will present the nagg tool capabilities, options and explain how it can be used with various JPSS products.