User's Guide

UPMEANS

Update the mean values of a TOVS water vapor climatology image

Function:

Update the mean values of a TOVS water vapor climatology image using a daily observation image.

Parameters:

IN
Input image. A TOVS water vapor daily obsevation image with values to add to OUT.

OUT
Output image. A TOVS water vapor climatology (fill) image to which values from IN are added.

Examples:

  1. LAS> upmeans in=wv140696 out=df010696

    The mean and count bands in the daily fill image df010696 are updated with values from wv140696.

Description/Algorithm:

Mean values are stored in band 1 and the number of values (counts) are stored in band 2 of TOVS water vapor fill images. These values are updated with new water vapor values using LOGICAL and MATH functions as follows:

    1. expand the mean values to sums (means*counts)
    2. mask the holes in the input image with zeroes
    3. add new values to sums
    4. update the counts to include new values
    5. calculate new means (sums/counts)
    6. store the new means and counts

Nonfatal Error Messages:

    None.

Fatal Error Messages:

    None.

User Notes:

    None.