c_acqread - Read one line of data from an AVHRR acquisition image

SYNTAX

FUNCTION c_acqread (fdesc, mnrbuf, tipbuf, imgbuf)

     long *fdesc;
     short *mnrbuf;
     short *tipbuf;
     short *imgbuf;

PARAMETERS

fdesc (long *, input)

File descriptor returned from c_acqopen().

mnrbuf (short *, output)

Buffer of short values where the HRPT Minor Frame data will be stored. This buffer must be previously allocated by the calling program and must be large enough to hold MNR_SIZ short values.

tipbuf (short *, output)

Buffer of short values where the TIP data will be stored. This buffer must be previously allocated by the calling program and must be large enough to hold TIP_SIZ short values.

imgbuf (short *, output)

Buffer of short values where the image data will be stored. This buffer must be previously allocated by the calling program and must be large enough to hold either LAC_SIZ or GAC_SIZ short values, depending upon the data type supplied to c_acqopen().

DESCRIPTION

One line of data is read from the current position within the acquisition image. The line of data is then unpacked and byte swapped if necessary, and the HRPT Minor Frame, TIP, and image data are all extracted and copied into the user's buffers. If the acquisition image is in BIL or BSQ format then the image data is converted to BIP.

RETURN VALUE

c_acqread() returns

    E_SUCC (0)  --> Successful completion.
    E_BOF  (-4) --> Operation failed.  BOF encountered.
    E_EOF  (-2) --> Operation failed.  EOF encountered.
    E_SMAL (-3) --> Operation failed.  The last buffer of data read from the
                    acquisition file is less than the expected number of bytes.
    E_FAIL (-1) --> Operation failed.