AVHRR Leads-ARI Polar Gridded Brightness Temperatures, Version 1

This data set consists of AVHRR imagery selected from hard copy 'quick look' images to provide the best coverage possible over the Arctic approximately every three days for a three-year period. Level-1B data from NOAA/SDSD have been calibrated and mapped to earth locations, then gridded to 1 km pixels on a basin scale to the polar stereographic projection. The projection is similar to that used by NSIDC to produce DMSP SSM/I polar brightness temperature and sea ice products. Each image was ranked for areal coverage of particular seas and for degree of cloud coverage. Passes covering a large area are generally favored over shorter passes with less cloud cover. The data set was developed in support of the Office Of Naval Research Arctic Leads Accelerated Research Initiative (Arctic Leads ARI). The aim of the Initiative was to develop a more thorough understanding of the oceanography, meteorology, and ice dynamics surrounding formation and evolution of leads in sea ice. The leads ARI field experiment took place from March to April 1992.

A spreadsheet containing the image rankings is available in hard copy (NOARL Tech. Note 118, April 1991); paper copies of the spreadsheet are available on request. Data set information is available on-line. Data are available via FTP.

本数据集选取自硬拷贝“快速预览”图像中的高级甚高分辨率辐射计（Advanced Very High Resolution Radiometer）影像，以在三年周期内约每三日获取北极区域的最优覆盖数据。来自NOAA/SDSD的一级B（Level-1B）数据已完成定标与地理定位，并被网格化为极地立体投影下、海盆尺度的1千米像素格网。该投影与美国国家冰雪数据中心（NSIDC）制作国防气象卫星计划（DMSP）专用微波成像仪（SSM/I）极地亮温及海冰产品所采用的投影一致。每幅影像均依据其对应海域的区域覆盖范围与云量覆盖程度进行评级。覆盖范围更广的过境影像通常优先于云量更少但覆盖范围较窄的过境影像。本数据集的开发旨在支撑美国海军研究办公室的北极冰间水道加速研究计划（Arctic Leads Accelerated Research Initiative，简称Arctic Leads ARI）。该计划的目标是深入理解海冰冰间水道形成与演化过程相关的海洋学、气象学及冰动力学机制。冰间水道ARI野外实验于1992年3月至4月开展。
包含影像评级结果的电子表格以硬拷贝形式公开（详见《NOARL技术报告118》，1991年4月）；该电子表格的纸质副本可按需索取。数据集相关信息可在线获取，数据可通过文件传输协议（FTP）下载。