1. A method for measuring the spectrum of at least one point in a scene, comprising: characterizing a camera which comprises a multi-color filter array and an array of photosensors; mounting the camera on an unmanned aerial vehicle; flying the unmanned aerial vehicle along a first flight path, the unmanned aerial vehicle being oriented such that the camera has a first orientation, a scene is within a field of view of the camera, and light from a point in the scene impinges on a first photosensor of the camera; capturing a first image of the scene while light from the point in the scene is impinging on the first photosensor; flying the unmanned aerial vehicle along a second flight path, the unmanned aerial vehicle being oriented such that the camera has a second orientation different than the first orientation, the scene is within the field of view of the camera, and light from the point in the scene impinges on a second photosensor of the camera; capturing a second image of the scene while light from the point in the scene is impinging on the second photosensor; transferring the first and second images from the camera to a computer; and computing the spectrum of the point in the scene based on at least the first and second images, said computing being performed by the computer system.