GPS Visibility Predictor

This application consists of a real time simulator of GPS constellation, including a suite of visualizations:
- World map with satellite geodetic positions, ground tracks and numeric GPS data,
- Sky map with satellite polar coordinates with regard to the local tangent plane,
- Visibility indicators, with satellites rise and set instants, and the number of visible and healthy satellites,
- Orbital planes and GPS constellation status.

The computation of GPS data is based on:
- Yuma or SEM format almanac (available online),
- UTC time from computer or user defined GPS time,
- User defined reference position,
- GPS operational advisory or constellation status (available online).

User manual:
https://fr.slideshare.net/EricOgier/gps-visibility-predictor-1010

Video demonstrations:
https://www.youtube.com/watch?v=3Bj1amvVjAo&ab_channel=Pseudonymeoriginal
https://www.youtube.com/watch?v=vJNg9mPjKy0&list=PLJXyTqQS4FL3QoWdlGj0WtT7nSYKWqBxv&index=3&t=0s&ab_channel=Pseudonymeoriginal
https://www.youtube.com/watch?v=UDLdMGO4AGI&index=4&list=PLJXyTqQS4FL3QoWdlGj0WtT7nSYKWqBxv&t=0s&ab_channel=Pseudonymeoriginal
https://www.youtube.com/watch?v=NFFLPsZ4xL4&index=5&list=PLJXyTqQS4FL3QoWdlGj0WtT7nSYKWqBxv&t=0s&ab_channel=Pseudonymeoriginal