On Mean Visibility Time of Non-repeating Satellite Orbits with Finite Sensor Range

Abstract

Depending on the parameters of a fixed ground station and on the orbital parameters of a non-geosynchronous satellite, different visibility times are offered to fixed ground stations. In this paper, the focus is on the mean visibility time of a non-geosynchronous satellite with non-repeating ground track as seen by a fixed ground station with a finite sensor range. A mathematical analysis is provided for the calculation of the mean visibility time. There are several possible application areas of these visibility statistics, like optimizing a gateway's latitude to maximize the mean visibility time of a satellite, thus maximizing the average amount of data that can be uploaded to or downloaded from a satellite during passes. The calculations show a good match with simulation results at all latitudes and the underlying mathematical approach is foreseen to be useful for analyzing and designing complete satellite constellations.

Capacity analysis of high‐throughput satellite links for Earth observation missions

“…The advantage of a direct link is that the free space path loss (FSPL) and the total link budget are better, than for a data relay link. However, the mean visibility duration and mean revisit frequency are significantly worse for the direct link – considering a single ground station for the direct link case – than for a data relay link . As a consequence, many ground stations are necessary all over the world in order to avoid too big data storage devices onboard the Earth observation satellites and to avoid too big data transfer rates.…”

On mean revisit frequency of non-repeating satellite orbits with finite sensor range

“…This section here is repeated based on [7] in order to help the reader understand how the finite sensor range of the fixed ground station is taken into account.…”

“…Reference [7] extended the work done in [6], by taking into consideration possible constraint of the fixed ground station on the sensor range. That paper provides the analytical solution of the mean visibility time between the fixed ground station and a satellite with non-repeating ground track, by assuming that the fixed ground station can have a certain minimum elevation angle and a certain maximum sensor range.…”

“…In case the satellite is seen from the fixed ground station above the minimum elevation angle and the satellite is closer to the ground station than the maximum sensor range, then the satellite is considered to be visible. This paper is a continuation of [7], and thus an extension of the work done in [6], because it provides the analytical solution of the mean revisit frequency, instead of the mean visibility time in case of a fixed ground station that has a certain minimum elevation angle and a finite sensor range. This extension can be useful in case of radar applications, or when a maximum communication distance can be determined based on the link budget, which thus has an influence on the mean revisit frequency, that can be used for communication.…”