The Nimbus 6 Electrically Scanning Microwave Radiometer: data rescue

The Nimbus 6 Electronic Microwave Radiometer (N6ESMR) was a Single frequency, 37 GHz, dual polarisation radiometer aboard the Nimbus 6 meteorological satellite and was active between June 22, 1975 and August 11, 1977. Its data is one of the few available sources for satellite sea ice monitoring, and might thus be used to expand the record of sea ice behavior if processed. However, the original level 1 radiance data were never archived, meaning that the only available data source is printed grayscale data images intended for manual analysis, which was stored on 70 mm film strips as both positives and negative. Scanned TIF images of these were made available in 2022 at the Goddard Earth Science Data Information and Services Center (GES DISC).For this project, a framework has been developed for recovering parts of the data from the TIFs using various image analysis and machine learning techniques all described in the corresponding paper. The utilized code is available at https://github.com/EHTellefsen/N6ESMR_rescue, while the resulting dataset is available here as NetCDF4-files for both positive an negative images from between 12 June 1975 and 31 March 1976. Full description of the contents of the files is available within the files.

Nimbus 6号气象卫星搭载的N6ESMR电子微波辐射计（Nimbus 6 Electronic Microwave Radiometer）为一款单频段、37 GHz、双极化辐射计，其工作时间为1975年6月22日至1977年8月11日。该设备所采集的数据是卫星海冰监测的少数可用资源之一，因此，若经过处理，或许能够扩展海冰行为记录。然而，原始的一级辐射亮度数据并未存档，目前可用的唯一数据源为专为人工分析而设计的打印灰度数据图像，这些图像以正负片形式存储于70毫米胶片上。2022年，这些图像的TIF扫描版本在戈达德地球科学数据信息与服务中心（Goddard Earth Science Data Information and Services Center，简称GES DISC）公开发布。在本项目中，研究人员已开发出一个框架，通过应用多种图像分析和机器学习技术从TIF图像中恢复部分数据，相关技术细节已在对应的论文中进行详细描述。所使用的代码可在https://github.com/EHTellefsen/N6ESMR_rescue找到，而由此生成的数据集以NetCDF4文件形式提供，包括1975年6月12日至1976年3月31日之间的正负图像。文件内容的详细描述包含在文件内部。