遥感在轨定标及地基验证

封面图片为遥感在轨定标及地基验证示意图。图中展示了遥感在轨定标及地基验证的基本思路，即基于覆盖典型大气条件和地理环境的地面定标及真实性检验场网（定标场要求地表均匀、大气干洁，真实性检验场要求地表覆盖类型多样化），利用搭载于不同高度观测平台（地基、高塔、无人机、航空飞机、高空科学气球、卫星等）的参考载荷或测量设备进行卫星过境时同步/准同步的地表、大气等关键参数获取，并结合大气辐射传输、尺度转换等过程，得到待定标载荷或者待验证数据产品的观测“真值”，以此来监测在轨卫星载荷性能变化情况，以及对遥感数据产品进行真实性检验，从而保证遥感卫星数据产品的精准性和一致性，支持空天遥感数据定量化应用。本期专刊的15篇论文汇总了遥感在轨定标及地基验证领域的最新研究成果。

Remote sensing on-orbit calibratioin and ground-based validation

The cover picture is a schematic diagram of remote sensing on-orbit calibration and ground-based validation. In this picture, the basic ideas of multi-route remote sensing on-orbit calibration and ground-based validation are illustrated: Based on ground calibration sites (which require homogeneous land surface, dry and clean atmosphere) and validation sites (which require diverse land covers), synchronous/quasi-synchronous surface/atmosphere key parameters are measured during satellite overpassing through reference senors or measuring equipment which on-board multiple platforms at different heights (such as ground shelf, observing tower, UAV, aircraft, high-altitude scientific balloon and satellite), then after considering atmospheirc radiative transfer and scaling effect, the pixel “true value” of the to-be-calibrated sensor or the to-be-validated product will be obtained, so as to monitor sensor performance variation of the satellite or conduct validation for the remote sensing product, thus guaranteeing accuracy and consistency of the remote sensing satellite product and supporting the quantitative applications of aerospace remote sensing data. The 15 papers in this special issue present the latest research achievements in the field of remote sensing on-orbit calibration and ground-based validation.