product_header_extensions

If the hdr.end.iExtendedHeaderOffset is non-zero, then there is a product header extension. This number is the byte offset from the beginning of the file to the extension.

The product header extension is an ASCII format, containing meta-data in name=value pairs.

The name value pairs are separated by newline characters.

The ASCII meta-data section is terminated by an ASCII zero.

This null may be followed by more null, and ends with a 0xff. This allows a parser to find the end by looking for a final 0x00 followed by a 0xff, and allows the sized to be padded to make the next section aligned, if desired.

Following the product header extension, there may be a binary data section. This binary data section is aligned based on the size of the data elements, which is specified in the meta-data. This is a general design intended to handle many needs for extending headers, such as listing sites in a composite, or listing algorithm attributes used to generate a data moment. In some cases, there may be multiple product header extension sections.

For example, the echo thickness product stores 2 binary data arrays, first the thickness, and second the average reflectivity over that interval. See, for example, the following name value pairs:

“data_type=Z”, “data_units=dBZ”, “x_size=120”, “y_size=120”, “data_storage=uint8_t”, “data_bits=8”, “data_source=DB_DBZ”, “data_size=14400”

A binary blob containing the average reflectivity follows the extension .