Fourier theory is pretty complicated mathematically. But there are some beautifully simple holistic concepts behind Fourier theory which are relatively easy to explain intuitively. There are other sites on the web that can give you the mathematical formul

Todos os meses, neste espaço, será publicado um conto enviado pelos nossos visitantes, que estará em destaque durante trinta dias e posteriormente disponível em arquivo. O objectivo é ajudar a dar o primeiro passo, vencer o receio sobre a aceitação

This tutorial is so easy to do and also very cheap. All you need to success is a 6mm long tripod screw (1/4") and a bottle-cork. IMPORTANT. You need to have the exakt thread on the screw for this purpose or you will destroy your cameras thread. If you are

The best way to make GIS coordinate transformations (when it is possible), is to use the EPSG database for performing it.