http://www.ncdc.noaa.gov/oa/pod-guide/ncdc/docs/klm/html/c8/s831-3.htmhttpbrowserNOAA KLM User's Guide, Section 8.3.1.3, LAC and HRPT Data Sets (AVHRR)Describes the characteristics and format of Local Area Coverage (LAC) and High Resolution Picture Transmission (HRPT) data sets for AVHRR instrument aboard NOAA KLM and NOAA-N satellites.information