ERROR CORRECTION FOR NOAA AVHRR DATA WITH REFERENCE TO THE SAME ORBITAL DATA

摘要

This paper describes a method that corrects the missing lines and the random noise pixels in NOAA images. NOAA images with the same orbit are received at various stations and overlap each other. To correct the errors in the original image, the other images which overlap the original one are referred. After specifying the overlapping area, missing lines are detected by checking time codes, and they are corrected by replacing with the corresponding lines from the reference data. Random noise pixels are recognized based on PN codes and the differences between their values and those of their neighbors. They are removed by assigning the new values from the reference data or their neighbors. This method was used to correct the NOAA images receiving at Tokyo by referring to the images from Bangkok and Ulaanbaatar. After correction, all errors were removed. The correcting time was less than 35 seconds per image.