3

This answer refers to information in this German Wikipedia page Technology Experiment Satellite

The page contains the following information:

I recognize apogee and perigee, inclination and period.

I don't see semi-major axis, but if it were there it would be the simple average of apo and peri, and in this case 541 km.

There I see Bahnhöhe mentioned several times in Wikipedia's Satellitenorbit, but what exactly does it mean?

Umlaufzeit:       95,3 min[1]
Bahnhöhe:         572 km
Bahnneigung:      97.7°
Apogäumshöhe:     567 km
Perigäumshöhe:    515 km

[1]  Bahndaten nach [TES](https://www.n2yo.com/satellite/?s=26957). N2YO, 18. November 2017, abgerufen am 18. November 2017
8
  • Höhe is altitude, Bahn is orbit. The question that you refer to already had that information. I do not think that possible inconsistencies in the data are language related. – Carsten S Sep 26 '20 at 12:42
  • @CarstenS there are comments under the question yes, but 1) I'm not certain of their validity and completeness, and 2) altitude doesn't make sense. Since words can sometimes have multiple meanings or usages in different contexts, I decided to open this up to this SE community; it's possible that there are more than one answer. – uhoh Sep 26 '20 at 13:25
  • 1
    Have a look at de.wikipedia.org/wiki/Erdn%C3%A4he: „In der Raumfahrt hingegen ist für erdnahe Satelliten die Bahnhöhe über der Erdoberfläche die entscheidende Größe: die Bahnhöhe im Perigäum, also die Perigäumshöhe, wird dabei häufig selbst als Perigäum bezeichnet.[1][2] Entsprechend wird die Bahnhöhe im Apogäum, also die Apogäumshöhe, kurz Apogäum genannt.“ The term itself really is not more specific. – Carsten S Sep 26 '20 at 13:46
  • 1
    It literally means what "altitude" means in english in he same context. What you have found is a inconsistency in data, but its not a language-related problem, its a data problem. You obviously can't have an orbit with an altitude higher than apogee. – Polygnome Sep 28 '20 at 17:17
  • 1
    The 572km comes from the ISRO page. "Orbit 572 km Sun Synchronous" (isro.gov.in/Spacecraft/technology-experiment-satellite-tes). I think somebody just copied together the data without cross-checking for consistency and didn't notice the discrepancy. – Polygnome Sep 28 '20 at 17:21
3

In the context of astronomy, the German word "die Bahn" means "the orbit". And "die Höhe" is "the altitude".

Together:

Bahnhöhe = altitude of an orbit

9
  • Thanks, but I'm still wondering; does bahnhöhe apply to the entire orbit, or only to a specific point in the orbit? Any orbit that isn't circular can not have a single altitude. In English the only time I've seen an orbit's altitude mentioned is in the context of a circular orbit around a spherical body. – uhoh Sep 26 '20 at 13:24
  • @uhoh: This question is out of the scope of German.stackexchange. I've studies physics, and I am very interested in astronomy, but I can't answer your question. For me this term simply makes no sense, especially not in the presence of two well defined terms like apogee and perigee. – Hubert Schölnast Sep 26 '20 at 13:41
  • 1
    Doesn't "Bahn" first and foremost act as a shortened version of "Flugbahn" (roughly: "flight path"), which in this case is an orbit? – O. R. Mapper Sep 27 '20 at 7:02
  • 1
    @HubertSchölnast: Neither does your answer contain a hint what "Bahn" might be a shortened form of, nor whether it is exactly synonymous with "orbit". Note that I'd like to somewhat correct myself in both points, though: Come to think of it, instead of "Flugbahn", an equally likely alternative is "Umlaufbahn". Furthermore, after some reading up, I have realized that "Bahn" on its own is indeed used a lot in astronomical texts, seemingly as a set term rather than a lengthy compound shortened ad hoc. Second, I couldn't find any clear statements on whether "Flugbahn" and "Orbit" could be ... – O. R. Mapper Sep 27 '20 at 19:45
  • 1
    @O.R.Mapper: What is unclear with this sentence »In the context of astronomy, the German word "die Bahn" means "the orbit".« The Word »Bahn« is not based on »Umlaufbahn«. The opposite is true: The words Flugbahn, Umlaufbahn, Kreisbahn, Ellipsenbahn, Erdumlaufbahn, Satellitenbahn etc are compound words containing »Bahn« are their last Element, so »Bahn« is NOT based on Umlaufbahn or any of the other words. All these words are based on »Bahn«. Fact is, that the question was »What does Bahnhöhe mean in the context of an satellite's orbit?« And I answered this question. – Hubert Schölnast Sep 28 '20 at 14:19
0

Actually, on an elliptic orbit, there is:

  • Perigäumshöhe (die Bahnhöhe im Perigäum, short: Perigäum) and
  • Apogäumshöhe (die Bahnhöhe im Apogäum, short: Apogäum)

The mean value is: die Bahnhöhe.

7
  • This doesn't check out. PH: 515. AH: 567, mean: 541. But above Bahnhöhe is 572. – infinitezero Sep 28 '20 at 14:47
  • @infinitezero: nope, look at the English page en.wikipedia.org/wiki/Technology_Experiment_Satellite . Perigee altitude 551 km, Apogee altitude 579 km – äüö Sep 28 '20 at 15:05
  • 1
    With those values, the mean value is still not the 572 mentioned above. So stating that the Bahnhöhe is the mean value, seems dubious to me, without other prove. – infinitezero Sep 28 '20 at 15:34
  • 1
    @HubertSchölnast I'm the OP and the topic of the question is the meaning of Bahnhöhe, not "values of orbital heights". The question of orbital heights is in a different SE site and linked in my question. I simply mentioned the situation there as potentially helpful background. If one doesn't find it helpful, then one does not need to pursue it. "A problem in Wikipedia was mentioned, therefore off-topic" is a bit extreme, no? – uhoh Sep 29 '20 at 3:31
  • 1
    @uhoh: No, it's not extreme. If a problem on Wikipedia is about German language, then it is ok to discuss it here too. But what is discussed here is not about German language. The discussion here is about how orbital height is related to apogee and perigee. This is not a discussion about aspects of German language but about astronomy and therefore offtopic on a site that is made to discuss aspects of German language. – Hubert Schölnast Sep 29 '20 at 5:43

Not the answer you're looking for? Browse other questions tagged or ask your own question.