MISR File Naming and Versioning Conventions
The MISR Product LocalGranuleID (filename) contains a string supplying version information. Prior to Software version V2.1.3, this version string consisted of two numerals in the last subfield of the LocalGranuleId. The numerals were incremented whenever a new delivery was made of the software that generates that product. In addition, product version numbers were incremented if a new ancillary dataset was delivered that significantly impacted the quality of the resulting product. Here's an example of the old versioning scheme,
was produced using newer software or ancillary datasets than
Since the V2.1.3 software delivery, all MISR Products contain an enhanced version string of the format:
Fnn_nnnn (or optionally Tnnn_Fnn_nnnn)
where nnnn specifies the old version number information with 4 numerals. Fnn specifies the format version of the product with the character F followed by two numerals which are incremented whenever a MISR software delivery results in a product format change. Tnnn is an optional field in some of the ancillary products which indicates a time range over which the product is valid. For example,
was produced using newer software than
Whereas the ancillary files,
represent files of the same format which are applicable to two different temporal ranges. The version numbers 0005 and 0001 bear no relation to each other. For more details, please see the Radiometric Calibration Quality Statement.
Early on in the mission, several significant changes to ancillary datasets were required. These changes triggered product version increments so that users could correlate an output product version number with a specific set of "latest and greatest" ancillary inputs. At this point in time, most of the static ancillary datasets have stabilized and major changes to them are not predicted. Therefore, product version numbers will not necessarily be incremented because of ancillary dataset deliveries. In fact, some ancillary datasets are being delivered on a regular schedule to account for temporal geophysical variation. This means that MISR product version numbers no longer map explicitly to a single group of ancillary inputs.
Temporal Ancillary Inputs: [ARP_INFLTCAL, RCCT (Cloud Thresholds)] Changes to these inputs will not change the output product version number.
Static Ancillary Inputs: [AGP, CGM, TASC, CSSC, PP] Changes to these inputs are not expected, but would cause output product version number to change.
Static Ancillary Inputs Likely to change: [SMART, ACP, ROI] Changes to these inputs are expected in the coming year, and such changes will affect the output product version number.
Although version numbers appear on each product file, they are controlled at the level of the software program that creates the file. Hence, if a program creates more than one type of product file, each product file it creates will share the same version number history. The common name used for these software programs is Product Generation Executable (PGE).