In traditional cameras the focal plane was a piece of film; modern ones use arrays of digital sensors.
在传统相机上以胶卷作为焦平面；现代相机使用数字传感器列阵的方式。
2
An image with intersection lines between grating planes and a known objective plane can be captured by a digital camera.
将光栅投影到已知目标平面，通过数字摄影得到光栅平面与目标平面相交的光栅图像。
3
DEM (Digital elevation Model) is a data set of plane coordinate or longitude, latitude, and elevation of the regular square grid points in some region.