| All economically feasible Land Mobile Satellite Communications (LMSC) systems are performance limited by fading caused by multipath scattering, vegetation shadowing, or blockage imposed by the environment. Traditionally, fade time series have been measured using an expensive transmitter platform technique. The determination of the effectiveness of advanced techniques, such as satellite diversity, through direct measurements required an even greater effort, but can be easily accomplished with the photogrammetric technique.;This dissertation develops photogrammetric techniques which makes satellite service predictions. Signal attenuation between satellite and user terminal on the earth is determined using photographic images of the sky taken with a camera through a fisheye lens having a 180;First, fast and effective still/video image processing algorithms, uses spatial image features and motion information, are employed to determine the line of sight (LOS) propagation state as clear, shadowed by trees, or blocked by buildings. Second, classified images are analyzed to derive state fractions as a function of elevation and azimuth. Third, this data is used to make fade statistics by collaborating with known signal distributions in their corresponding states.;This research produced the first implementation of photogrammetric measurements in LMSC field by (a) developing an imaging hardware and software for photogrammetric measurements, (b) making environment quantification based on Clear, Shadowed and Blocked state fractions, (c) measuring satellite personal communication systems (S-PCS) fading, (d) predicting elevation angle and environment dependence of S-PCS fading, (e) tracking LOS state in the video images to generate a signal time series, and a Markov model of the narrow-band communication channel that describes state duration and transition characteristics, (f) estimating satellite diversity gain's dependence on combining and hand-off diversity schemes, number of satellites and satellite planes, user latitude and environment, (g) measuring good-call completion probability. A new urban environment signal propagation model is also presented by establishing the importance of specular reflections under urban blockage conditions. Processing results are from sampled urban, suburban and rural environments in the USA, Canada and Japan. |
