After downloading the files from eg.: https://gpm1.gesdisc.eosdis.nasa.gov/da ... /2006/336/ first file seems to have inaccessible variables such as 'ScanTime', while brightness temperature 'Tc' shows length of the data is zero. The same happens randomly for some other years and satellites (N16, N17, N18) files.
I wonder what should be the cause for this and look forward on your reply which I hope will shed some light on it.
We have determined that the granule you indicated is an empty file due to a data outage. The Precipitation Processing System (PPS) has an outage table:
https://arthurhou.pps.eosdis.nasa.gov/D ... 05_V06.pdf
This can be examined if you encounter other empty granules to determine if they were caused by a data outage.
It is also possible to examine the global file attributes stored as "FileHeader". In this case, the string "EmptyGranule" is set to "EMPTY", confirming that this file has no data. The image shows an excerpt of the global file attributes with the "EmptyGranule" string at the end of the third line.