Satellite Simulator continue to make progress…
We are making progress on the development of Questiny’s Land-mobile Satellite Network Simulator (LMSNS). We have just completed its ability to download two-line elements from NORAD, propagate those elements to a common time, and predict the satellite locations. Below is a plot of the satellite orbits for 200 minutes. The four satellite planes are clearly visible.
In addition, our tool can now estimate the visibility of the satellite relative to a location on the earth. We have taken a location of 0.0 degrees N, 0.0 degrees E, and determined the elevation angle to each of the satellites. This location was chosen as the equator provides the most pronounced gaps for LEO constellations. The satellites are spaced the farthest apart along the equator, so we felt that it might be a most interesting case. The orbit locations were calculated every 2 mintues throughout the 200 minute simulation duration. Calculating these elevation angles that were above 5 degrees and summing the number of such satellite at each time period results in the number of visible satellites. We have plotted this in the graph below.
The interesting thing about this plot is that most of the time an earth terminal will have good visibility to the constellation, but it is not without gaps. We see that there is about a 2 minute gap around 82 minutes into the simulation, and a one minute gap around 19 minutes into the simulation. That means using Orbcomm for continuous back-haul communications is difficult in the current constellation. The reasons for this gap may be due to an incomplete constellation. If so, these gaps would disappear when the constellation is fully populated. In addition to the technical algorithms and software, wer are making progress on the GUI as well. We currently have a mock-up of the GUI, and are developing a working prototype within Matlab. We hope to have furhter progress on it this week.
