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.

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

INDF = INTEGER (Given)

PNTR = INTEGER (Returned)

EL = INTEGER (Returned)

BAD = LOGICAL (Returned)

STATUS = INTEGER (Given and Returned)

• 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.