The MOD08_E3 (Eight-Day) product will be produced at the MODAPS facility at the NASA Goddard Space Flight Center. MODAPS will produce 100% of the MODIS Atmosphere Eight-Day Product (MOD08_E3). The data volume will be a single HDF file of 600 MB per week.

Production Rules

For the MOD_PR08E process (PGE70) the following production rules apply:

Run PGE70 once for every series of eight data-days if, at the time that all eight MOD08_D3 daily input granules are expected, one or more files are in fact present. However, no more than 8 files may be present.

The start day of the PGE70 8-day processing cycle is arbitrary except that it must begin on or prior to the first day of MODIS Earth View data acquisition. Once initiated, the processing cycle repeats, uninterrupted every eight days until the end of the MODIS mission. Thus, the sequence of 8-day cycles is never reset throughout the life of the instrument.

Production Rules Q & A

Is it true that the MODIS Atmosphere Eight-day product (MOD08_E3) may only contain 1 day of MODIS data?

Yes. It should be noted that there may be lengthy periods when the satellite is unable to transmit data or the data are corrupted or lost. In this case, the system works with the available data.

Would these MOD08_E3 files be regenerated later if later more days were to become available?

During reprocessing initiatives one expects to get a more complete input data stream and presumably a better product.

How would an end user know how many days (and which ones) went into a particular MOD08_E3 file?

The ECS metadata contains the temporal coverage of the processing period. It also provides the names of the input files used to generated the output product. However, it would be desirable to add HDF file metadata to indicate the number of data days used.