C52

The [BD ORTHO® History](http://professionnels.ign.fr/bdorthohisto) provides several orthophotos using shots taken on different dates in the same area of the field. Two full covers of metropolitan France are available. This new historical database is interoperable with the Grande Scale Reference System (RGE®), and responds to the problem of the integration of yesterday’s data into today’s tools. [logo de l IGN](http://professionnels.ign.fr/sites/all/themes/ign/logo.png)BD ORTHO® 历史数据集（BD ORTHO® History）<http://professionnels.ign.fr/bdorthohisto> 提供了同一区域内不同拍摄日期的多幅正射影像。目前可获取两份覆盖法国本土全境的完整正射影像数据集。该新型历史数据库可与大比例尺参考系统（Grande Scale Reference System，RGE®）实现互操作，能够解决历史数据向当前工具整合的痛点问题。 IGN标志<http://professionnels.ign.fr/sites/all/themes/ign/logo.png>