Declassified Satellite Imagery - 1

The first generation of U.S. photo intelligence satellites collected more than 860,000 images of the Earth's surface between 1960 and 1972. The classified military satellite systems code-named CORONA, ARGON, and LANYARD acquired photographic images from space and returned the film to Earth for processing and analysis. The images were originally used for reconnaissance and to produce maps for U.S. intelligence agencies. In 1992, an Environmental Task Force evaluated the application of early satellite data for environmental studies. Since the CORONA, ARGON, and LANYARD data were no longer critical to national security and could be of historical value for global change research, the images were declassified by Executive Order 12951 in 1995. The first successful CORONA mission was launched from Vandenberg Air Force Base in 1960. The satellite acquired photographs with a telescopic camera system and loaded the exposed film into recovery capsules. The capsules or buckets were de-orbited and retrieved by aircraft while the capsules parachuted to earth. The exposed film was developed and the images were analyzed for a range of military applications. The intelligence community used Keyhole (KH) designators to describe system characteristics and accomplishments. The CORONA systems were designated KH-1, KH-2, KH-3, KH-4, KH-4A, and KH-4B. The ARGON systems used the designator KH-5 and the LANYARD systems used KH-6. Mission numbers were a means for indexing the imagery and associated collateral data. A variety of camera systems were used with the satellites. Early systems (KH-1, KH-2, KH-3, and KH-6) carried a single panoramic camera or a single frame camera (KH-5). The later systems (KH-4, KH-4A, and KH-4B) carried two panoramic cameras with a separation angle of 30 degrees with one camera looking forward and the other looking aft. The original film and technical mission-related documents are maintained by the National Archives and Records Administration (NARA). Duplicate film sources held in the USGS EROS Center archive are used to produce digital copies of the imagery. Mathematical calculations based on camera operation and satellite path were used to approximate image coordinates. Since the accuracy of the coordinates varies according to the precision of information used for the derivation, users should inspect the preview image to verify that the area of interest is contained in the selected frame. Users should also note that the images have not been georeferenced.

美国第一代照相侦察卫星（U.S. photo intelligence satellites）于1960年至1972年间，累计获取了超过86万幅地球表面影像。这批代号为CORONA、ARGON及LANYARD的保密军事卫星系统，从太空获取摄影影像并将胶卷送回地球进行冲洗与分析。此类影像最初用于侦察任务，并为美国情报机构制作地图提供支撑。1992年，环境专项工作组（Environmental Task Force）评估了早期卫星数据在环境研究中的应用价值。鉴于CORONA、ARGON与LANYARD的数据已不再关乎国家安全，且具备全球变化研究的历史价值，美国于1995年通过第12951号行政命令（Executive Order 12951）将这批影像解密。首枚CORONA卫星于1960年从范登堡空军基地（Vandenberg Air Force Base）发射升空并完成首次任务。该卫星搭载望远相机系统获取照片，并将曝光后的胶卷装入回收舱。回收舱（又称"桶状容器"）脱离轨道，在降落伞辅助下返回地球，随后由飞机完成回收。曝光后的胶卷经冲洗后，其影像被用于各类军事应用场景的分析。美国情报界使用"锁眼（Keyhole）"编号体系来标识卫星系统的特性与任务成果：CORONA系统对应KH-1、KH-2、KH-3、KH-4、KH-4A及KH-4B；ARGON系统对应KH-5；LANYARD系统对应KH-6。任务编号用于索引影像及相关附属数据。该系列卫星搭载了多种相机系统：早期型号（KH-1、KH-2、KH-3及KH-6）搭载单台全景相机，或单台画幅相机（如KH-5）；后期型号（KH-4、KH-4A及KH-4B）则搭载两台间距夹角为30度的全景相机，一台朝前拍摄，另一台朝后拍摄。原始胶卷及与任务相关的技术文档由美国国家档案与文件署（National Archives and Records Administration, NARA）馆藏。美国地质调查局地球资源观测与科学中心（USGS EROS Center）存档的胶卷副本被用于制作影像的数字版本。研究人员通过结合相机运行参数与卫星轨道数据的数学计算，来估算影像的坐标。由于坐标精度取决于推导过程中所用信息的精确程度，用户应查看预览影像，以确认目标区域包含在所选中的画幅内。同时需注意，这批影像尚未进行地理配准。