Pass over a point prediction using TLE data

[bcazabonne]

Hi @shresthdeepgupta

Welcome to the Orekit forum.

@shresthdeepgupta

However, I’m unable to find the maximum elevation for these passes. Is it possible to attach multiple detectors to a propagator?

Of course! The addEventDetector() merthod can be called multiple times. Please find an example developed by Luc showing how to add both an ElevationDetector and an ElevationExtremumDetector to your propagator (Comparing Access Time Analysis SGP4:STK and OreKit - #6 by luc)

@shresthdeepgupta

Also, what the values maxCheck and threshold meant for , if anyone can point me in the right documentation.

In order to explain what those parameters represent, it is important to know how event detection is based in Orekit. Each event detectors in Orekit are represented by a function. We call it the g function. For instance, for an ElevationDetector, the function is the difference between the satellite elevation and the elevation threshold initialized by the user. An event is detected when the sign of the g function change.
Depending the integrator step, the change of the sign is first detected with a poor accuracy. So, Orekit (and Hipparchus) will improve the event detection epoch with a small dichotomy around the detection epoch. The parameter threshold represents the convergence threshold in the event time search. And the parameter maxCheck represents the time interval for the search.

@shresthdeepgupta

Ultimately, I want to predict the passage over an area for remote-sensing. What detector should be used there, or maybe some example for covering an area rather than a single point on the ground.

For this you can use GeographicZoneDetector.

Best regards,
Bryan