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Quality processing commands
These commands handle the representation of data quality. The default
way of specifying data quality within ASTERIX is by explicit QUALITY
values separate from the data values. These QUALITY values are stored
in an unsigned byte in accordance with SGP38. The meaning of each bit
is given in the section 'Quality_values' below. The default behaviour
in ASTERIX is for data to be considered bad if any QUALITY bit is set.
It is possible to alter this behaviour by applying a MASK to the QUALITY.
See the section 'Masking_quality' below. In general data points with bad
QUALITY are ignored by ASTERIX. However, in some cases this is not
possible because ASTERIX is using external software which is unaware of
the QUALITY values. Two dimensional graphics is an example. In this
case it is possible to exclude bad data by using the magic value
representation. See the section on 'Quality_handling' in GRAFIX help
and the section 'Magic_values' below. Other packages (eg. KAPPA) use
the magic value representation by default and the 'Magic_values' section
explains how to transport datasets between ASTERIX and such packages.
Subtopics:
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