TIMED GUVI Imaging Level 1C Disk

This Level 1C data product measured over multiple scans on the disk contains data directly measure by the sensors such as photometer counts, uncertainties, light intensities and pointing information derived from the GUVI raw sensor data and the TIMED Satellite ephemeris data. The data are geolocated at a 150 km altitude, then gridded and binned to a 25 km X 25 km resolution GUVI-based coordinate system consisting of the along orbit position of the sensor and the angle of the scan from the nadir position. This gridding eliminates overlap from scan to scan due to the large instantaneous field-of-view of GUVI (about 12 degrees) and involves coaddition to place the values on a uniform instrument shared grid. The data is then determined whether its from day, night, aurora or twilight pixels.本1C级数据产品基于磁盘存储的多轮扫描数据构建，包含由传感器直接采集的光度计（photometer）计数、不确定度（uncertainty）、光强（light intensity）数据，以及源自GUVI原始传感器数据与TIMED卫星星历数据的指向信息（pointing information）。该数据首先在150千米高度完成地理定位，随后被网格化与分箱处理，转换至基于GUVI的25千米×25千米分辨率坐标系，该坐标系由传感器的沿轨位置与相对于天底点（nadir position）的扫描角度构成。由于GUVI的瞬时视场（instantaneous field-of-view）较大（约12度），该网格化步骤可消除不同扫描之间的数据重叠，并通过共累加操作将各数值统一至共享的仪器网格中。随后将对该数据进行判别，以区分其像素属于日间、夜间、极光（aurora）还是曙暮（twilight）时段。

搜集汇总

背景与挑战

背景概述

该数据集是TIMED卫星GUVI仪器的Level 1C成像数据产品，覆盖2002年至2007年，提供地球近表面区域（包括大气层、电离层和极光区）的辐射测量数据。数据经过地理定位和网格化处理，分辨率为25公里×25公里，包含多波段光强度、不确定性和指向信息，并以开放许可（CC0-1.0）通过多种格式（如NetCDF、CDF）公开访问。