NDF_MAPQL - Map the quality component of an NDF as an array of logical values

Description:

The routine maps the quality component of an NDF for read access, returning a pointer to an array of logical values. Elements of this array are set to .TRUE. if the bit-wise "AND" of the corresponding quality value and its effective bad-bits mask gives a zero result, indicating that the corresponding NDF pixel may be used in subsequent processing. Other array elements are set to .FALSE., indicating that corresponding NDF pixels should be excluded from subsequent processing.

Invocation:

CALL NDF_MAPQL( INDF, PNTR, EL, BAD, STATUS )

Arguments:

INDF = INTEGER (Given)

NDF identifier.

PNTR = INTEGER (Returned)

Pointer to the mapped array of logical values.

EL = INTEGER (Returned)

Number of values mapped.

BAD = LOGICAL (Returned)

This argument is set to .TRUE. if any of the mapped values is set to .FALSE. (i.e. if any NDF pixels are to be excluded as a consequence of the associated quality values). Otherwise it is set to .FALSE..

STATUS = INTEGER (Given and Returned)

The global status.

Notes:

• If the quality component's values are undefined, then this routine will return a pointer to an array of .TRUE. values.

• Note that this routine only obtains read access to the quality component; changes made to the mapped values will not be reflected in changes to the NDF's quality values.

• This routine disables automatic quality masking, so that subsequent access to other NDF array components via the same identifier will take no account of the possible presence of associated quality values.

• If this routine is called with STATUS set, then a value of 1 will be returned for the EL argument, although no further processing will occur. The same value will also be returned if the routine should fail for any reason.