Vizard demo does not match the program

[wanglishuo]

@schaubh Hello professor, I have been experiencing some issues while using Vizard recently,
My scene is a satellite in the Earth Moon transfer orbit observing the ground station, I observe whether the satellite is within the observable range of the ground station by recording the "hasAccess" message in "groundLocation. accessOutMessages [-1]". If the message 'hasAccess' is 1, it indicates that the satellite is within the observation range of the ground station, and the corresponding Vizard demonstration should also show that the satellite is within the observation range of the ground station.But my result is that when 'hasAccess' is 1, Vizard's demonstration shows that the satellite is not within the observation range of the ground station.

I conducted a test on this issue. Firstly, I created a Python file in which I did not use the Spice module and created my scenario. In this program, I ensured that when the message "hasAccess" was set to 1, the result demonstrated by Vizard was that the satellite was within the observable range of the ground station, and I recorded the latitude and longitude coordinates of the ground station at that time.Then I created a second Python file with the same content as the first Python file, the only difference being that I used the Spice module to create the gravitational body and set the ephemeris. The coordinates of the ground station position I used were also the same. After I set the ephemeris, the observation range of the ground station will change with the rotation of the Earth, but the fact seems to be that in my program, the Earth does not seem to rotate, and it is still the same as when I did not use Spice to set the ephemeris. However, Vizard's demonstration simulated the rotation of the Earth. So now in Vizard, we can see that the observation range of the ground station is changing with the rotation of the Earth, and the satellite is not within the observation range, but the message "hasAccess" is 1.

So what is the reason for this problem, and are there any areas that I haven't set up properly? Thank you!

[schaubh]

Given this info it is hard to say what might be happening. Keep in mind that Vizard uses an independent kinematics stack. You say that with Spice included Earth is rotating in Vizard, but not in BSK? This is not possible. Vizard reads the actual inertial states of all objects (planets, sun, spacecraft, panels, moon, etc.) and displays their position and orientation. There is no way Vizard can rotate an object if the state message from BSK is not telling it to do so. I would double check your setup and assumptions.

Regarding hasAccess state, it makes sure that relative to the ground location the spacecraft is above a minimum elevation angle minimumElevation, but is also makes sure you are within maximumRange. If maximumRange < 0 (default behavior), then the range checking is turned off. Make sure the maximumRange value is set in meters, not kilometers.

[wanglishuo]

Thank you professor! I have already solved the problem.