What is a push broom sensor?

Answer 1

There are many dimensions that sensors work in. A normal camera, for instance, works in 2 dimensions and basically takes an average of all visible wavelengths it can see as the color it receives per pixel. Spectral imagers are capable of filtering out individual wavelengths to see the intensity of light at those individual wavelengths for analysis purposes. These types of cameras, therefore, have 3 dimensions they need to work in: 2 spacial and 1 spectral. But, as of now, there really is no imaging system that can do 3 dimensions simultaneously one of the dimensions needs to be spread through time. In some systems they scan the various wavelengths of a full image in succession (2 spacial dimensions with spectral spread over time). Others are able to scan a very long narrow area and split it up into many wavelengths at once and move the view of the scene perpendicular to the long side of the view(1 spacial and the spectral dimensions simultaneously and the second spacial dimension over time). The second method is a pushbroom system it views a narrow area and moves the view along to see a full scene over time.

I hope that was moderately clear.