Sviluppo simulatore/data plotter per la missione Tianwen-1

Traiettoria prevista attualmente:

image

Dati grezzi (link)

Note contenute nei dati grezzi:

TRAJECTORY:
This trajectory is an UNOFFICIAL one based on optical and radio ground
observations collected by numerous volunteers.

It does not include FUTURE maneuvering events that will take place en-route
to Mars (no information on them has been made public), so will likely be
accurate only for days or weeks into the future past the “revision date”
noted above. It terminates an hour after Mars closest-approach since the
spacecraft would likely have been maneuvered into orbit by that time.

This as-is trajectory is being made available through Horizons by request,
to support volunteer ground-based radio tracking efforts described here:

https://destevez.net/2020/07/tracking-tianwen-1s-orbit-to-mars/
http://www.r00t.cz/Sats/Tianwen1
https://amsat-dl.org/chinese-mars-probe-tianwen-1-successfully-received-by-amsat-dl/

Dal sito destevez.net:

Since launch, Tianwen-1 has transmitted as part of its telemetry some state vector data, giving its position and velocity vector every 32 seconds. This has allowed us to propagate, track and study its trajectory.
[…]

Today we have noticed that starting at some point on 2021-02-08, Tianwen-1 is now transmitting state vectors using a different, Mars-centric frame of reference.

Dai tuoi dati non capisco il periapside dell’orbita presunta. Devo prendere 3.936419344843773E+03, il valore delle 12:07, e sottrarre il raggio di Marte, 3.389,5 km trovato su un altro sito, vero?
Quindi all’incirca dovrebbe passare a 547 km dalla superficie, secondo queste stime.

Il raggio di Marte tocca specificarlo a mano nell’url (parametro radius) perchè c’è un errore da qualche parte nella pagina che non riesco a trovare, in teoria per i corpi presenti nel DB della pagina dovrebbe saperlo da sè; comunque l’ho preso dal file stesso dei dati grezzi, c’è questa riga (in effetti a rivederlo ora dovevo metterci 3396, non 3376, ma a cambiare l’url ci vuole poco…):

Center radii : 3396.2 x 3396.2 x 3376.2 km {Equator, meridian, pole}

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