NOAA Climate Data Record (CDR) of AVHRR Polar Pathfinder (APP) Cryosphere Verison 1.0 (Version Superseded)

*Note: This dataset version has been superseded by a newer version. It is highly recommended that users access the current version. Users should only use this version for special cases, such as reproducing studies that used this version.* This NOAA Climate Data Record (CDR) contains the AVHRR Polar Pathfinder (APP) product. APP is a fundamental CDR comprised of calibrated and navigated AVHRR channel data (reflectances and brightness temperatures), viewing and illumination geometry (sensor scan angle, solar zenith angle, and sun-sensor relative azimuth angle), Universal Coordinated Time (UTC) of the data acquisition, and a surface type mask. The data are twice daily composites of up to 23 orbits on a 5 km Equal-Area Scalable Earth (EASE)-Grid twice daily over both poles, the Arctic and Antarctic, from 1982 to the present. The daily APP composites are centered on local solar times of 14:00 (high sun, but could be nighttime for some polar areas in winter) and 04:00 for the Arctic or 02:00 for the Antarctic. The APP covers the north polar region (Arctic) from 48.4 degrees northward, and the south polar region (Antarctic) from -53.2 degrees southward.