Sensors of modern lightning locating systems allow for determining various lightning parameters thus providing valuable information not only for lightning research but also for ground-based assets at risk (e.g. electric power utilities, airports, forestry, etc.) However, those sensors are not designed to record electromagnetic fields from lightning discharges over a longer period of time. Therefore, a measurement station is operated in Neudorf, Upper Austria, which is not subject to this limitation. Radiation components of lightning generated vertical electric fields are recorded by means of a plate antenna mounted on the roof of a house about 8 m above ground. The investigation of the effect of the building on the measurements, i.e. the determination of the antenna enhancement factor (AEF), is the main goal of this master thesis. In order to determine the AEF of the roof antenna, a reference measurement with more or less equal equipment was carried out simultaneously with the antenna placed on ground in a nearby meadow. 725 CG flashes were selected from all records and the values of peak electric fields from both stations were compared. Many statistical analyses have been conducted to obtain a reliable value for the AEF. The results show that the enhancement factor is not or only weakly correlated to other factors like lightning peak current, peak electric field, distance or azimuth of the lightning discharge. Due to a 50 Hz signal superimposed on the reference measurement and a rather small number of recorded positive flashes it is not yet clear whether we have to distinguish between positive and negative discharges (although there is no physical reason to do so). In case of a distinction the AEF for positive lightning is characterized by the following statistics: mean M=2.52, standard deviation SD=0.21, median -_(1/2)=2.56; for negative lightning it has been found that M=2.60, SD=0.21 and -_(1/2)=2.63. If no distinction is made the statistics of the AEF are given by M=2.59, SD=0.21, -_(1/2)=2.62. Taking into account the typical uncertainties in lightning research it is deemed suitable to employ an AEF of 2.6 for practical future application. The lightning research station at the Gaisberg Tower in Salzburg, Austria, provides valuable ground-truth information on lightning discharges to the radio tower and permits to evaluate the performance of ALDIS. Within this thesis electric fields from strikes to the tower have been evaluated, compared to fields from ground-initiated return strokes and the so called tower effect, i.e. field enhancement due to an elevated strike object, has been investigated. Furthermore, peak currents from tower-initiated lightning were regressed on the corresponding electric fields in Neudorf. However, the evaluation of more measurements will be necessary.