Vegetation is essential for life on earth. Nowadays, vegetation (such as forest areas) is monitored only with an inadequate resolution (in time and space) by several systems, in most cases by satellite or airborne remote sensing or manually and inefficiently. However, the process of data capturing is time consuming, in some cases unreliable and expensive. MuSe-3D will develop a flexible system which can be used for measuring and monitoring vegetation areas more efficiently by using small UAVs. The main goal of the project is the development and evaluation of a multi-spectral measurement system for monitoring vegetation (e.g. forest) by UAVs (unmanned aerial vehicles). We will deliver the whole system incl. hardware (measurement system) and software for analyzing, storing and handling the data sets. The key component is a small, light, and stand-alone measurement system that not only can be mounted on a conventional UAV but also on other mobile platforms.