Aktivitäten in Teilprojekt 5
The Mobile Unit for Field SPEctroscopic Measurements (MUFSPEM)
*Department of Land Use Planning and Nature Conservation (http://www.lrz-muenchen.de/~lnn/), Technical University of Munich
**Institute of Plant Nutrition (http://www.weihenstephan.de/pe/pflzern.html), Technical University of Munich
The Mobile Unit for Field SPEctroscopic Measurements (MUFSPEM) is constructed by the Department of Land Use Planning and Nature Conservation in collaboration with the Institute of Plant Nutrition of the Technical University of Munich. The original form of this construction has been developed and realized by Dr Thomas Schneider (Department of Land Use Planning and Nature Conservation).
The concept for the measurement arrangement was to be high, mobile and fast enough to achieve an acceptable amount of measurements for more than one surface during comparable illumination conditions (Fig.1).
The measurement construction that has been developed allows to register in situ the multispectral and multiangular radiation from the vegetation canopy from a height of about 10 meters above the objective. Nadir or oblique incomimg radiation is registered by the use of GER 3700 Spectroradiometer and a particularly for this purpose designed pan-tilt head (Fig.2).. The optic that can be used is 3° or 10° for the nadir measurements and 23° fiber optic for the oblique looking ones.The pan-tilt motor driven head is controlled from a computer performing the measurements following a predefined sequence of look directions from an ASCII file. As a result, it is easy to program the instrument to cover a semi-hemisphere in predefined azimuth and zenith angle steps.
The Mobile Unit for Field SPEctroscopic Measurements (MUFSPEM) is constructed in the frame of the IKB Duernast precision farming project (http://ikb.weihenstephan.de), in which a series of measurements should be carried out, in an effort to acquire information about plant growth, N-intake, available water and N in the soil with īnon-contact` measuring methods in the field. The comparison among simultaneously acquired plant and soil water potential, spectroscopic, IR-thermometric and light condition measurements should lead to a weather-independent online water-sensor-system. Furthermore, these field spectroscopic measurements are going to be integrated into a raw data database, which will be used to approximate the bidirectional reflectance distribution function (BRDF) of the test-plots. After the collection of the geophysical characteristics of the investigated vegetation area will take place the invertion of "physical reflectance models". The main aim is to create a link, which will successfully relate the reflectance signal with the geophysical characteristics of the investigated vegetation area.