美国用于林业的遥测技术有以下几方面:多层颜色的航摄胶片。这种胶片也叫“暴露目标”的胶片,有对绿、红和红外线感光的三层,因此可用黄色滤光镜摄影。多相机组合的航空摄影。这种航摄方法是用数个装有对不同光谱感光胶片的摄影机同时航摄、美国对此制定了几个方案。曾用四个分 The United States telemetry technology for forestry has the following aspects: multi-color aerial photo film. This film, also called “target exposure” film, has three layers of light sensitive to green, red and infrared so it can be photographed with a yellow filter. Multi-camera combination of aerial photography. The aerial photographing method uses simultaneous aerial photography with several cameras with different spectral sensitized films. The United States has formulated several plans for this. Had used four points