有什么方法可以计算出卫星(ISS)的视觉大小? [英] Is there any way to calculate the visual magnitude of a satellite (ISS)?
问题描述
仅在我的Raspberry Pi上使用了PyEphem的基础知识.工作真的很好.
Just got the basics of PyEphem working on my Raspberry Pi. Working really well.
获取对象(在我的情况下为ISS)的next_pass的方法非常有用...但是我确实也希望能够考虑观察者的实际视觉大小.这样，我可以只列出ISS的可视通行证，而不是全部.
The approach to getting the next_pass of an object (in my case the ISS) is very useful... but I really also want to be able to take in to account the actual visual magnitude for the observer. That way I could list only the VISIBLE passes of the ISS rather than all of them.
是否有某种方法可以通过考虑观察者，国际空间站和太阳的位置来计算视觉强度?
Is there some method to calculate the visual magnitude by accounting for the position of the Observer, the ISS and the Sun?
谢谢您的建议.
推荐答案
答案找到了我自己的答案.务必阅读文章的其余部分以获取详细信息.快速总结是，我计算了太阳和iss之间的分离角.然后使用两个已知的距离(sun.earth_distance)和iss.range)求解三角形以获得相位角.这将被泵送到下面的幅值方程式和VIOLA中.由此返回的值似乎接近Heavens-above.com上的值.这就是我想要的.
ANSWER Found my own answer to this question. By all means read the rest of the post for details. The quick summary is that I calculate the separation angle between the sun and the iss. With the two known distances (sun.earth_distance) and iss.range) I then solve the triangle to get the phase angle. This gets pumped in to the magnitude equation below... and VIOLA. The values returned by this seem to be close to what is on Heavens-above.com. That's all I wanted.
See this post for the actual Python code I use to calculate the phase angle.
注意:我真的不确定如何处理我的编辑.我看到一个事先的注释，即我的编辑将在审核后显示-但是我希望仍然可以在帖子中看到我的编辑.现在什么都没有了.在任何情况下，我的编辑实际上都是对自己问题的解答.主持人:请不要删除此答案.它包含一个针对我自己进一步研究的问题的适当答案，我认为这是相关的.谢谢你！！
NOTE: I am really not sure how my edits are handled. I saw a prior note that my edits would be displayed after moderation - however I expected to still see my edits shown in the post. Now nothing is there. My edits are actually more of an answer to my own question in any case. MODERATOR: Please do NOT delete this answer. It contains an appropriate ANSWER to my own question that I have further researched and I think is relevant. THANK YOU!!
许多提供卫星预测的在线服务实际上也提供幅度预测. Heavens-Above.com就是这样的网站之一，因此肯定有一些技术可以做到这一点.
Many online services that supply satellite predictions do in fact provide magnitude predictions as well. Heavens-Above.com is one such site so there are definitely techniques out there to do this.
《天堂之上》中关于国际空间站的预测通常是相当可靠的，并且要考虑到它何时会传递到地球的阴影中. 实际上PyEphem确实显示卫星是否被遮盖. 身体.被遮盖
The predictions for the ISS that are available on Heavens-Above are generally pretty reliable and take in to account when it will pass in to the earths shadow. In fact PyEphem does show if a satellite is eclipsed or not. body.eclipsed
此外，尽管已知ISS偶尔会比预期的要亮一些，但这仍然是很少见的事情，而且我对预测这一点不太感兴趣(而且我同意尝试这样做似乎毫无意义).铱的票价当然在视觉幅度上变化很大-但根据观察者/卫星/高度抛光的天线和太阳角的位置，还是很可预测的.
Also while the ISS is known to occasionally flash brighter than predicted that is still a pretty rare occurrence and I'm not too interested in predicting that (and I would agree trying to do that seems rather pointless). Iridium fares are of course very variable in visual magnitude - but nevertheless are very predictable based upon the location the observer / satellite / angle of their highly polished antenna and the sun.
如果可能的话，我实际上只是在寻找一些使用PyEphem库进行计算的方法的指针.
I'm really just looking some pointers to an approach to calculate this using the PyEphem library if possible.
再次感谢任何实际执行此操作的指针.
Thanks again for any pointers to actually do this.
我在这里找到了关于这一点的讨论-> http://www.satobs.org/seesat/Apr-2001/0313. html
I found a discussion about this very point here-> http://www.satobs.org/seesat/Apr-2001/0313.html
>Mag = Std. Mag - 15 + 5*LOG(Range) -
> 2.5*LOG(SIN(B) + (pi-B)*COS(B))
>
>where Range is in km, and B is in radians and measures
>the angle from the sun to the satellite to the observer.
>At full phase, B is 0; at new phase, B is pi (i.e.
>satellite transiting the sun).
enter code here
我在ISS上使用的Standard.Mag是-1.3(1000 km时的固有亮度)-一些在线资料来源对此进行了说明.例如 http://satobs.org/seesat/Aug-2005/0114.html和这一个 Quicksat内在震级文件:qsmag.zip
Standard.Mag I use for the ISS is -1.3 (intrinsic brightness at 1000km) - several online sources reference this. e.g. http://satobs.org/seesat/Aug-2005/0114.html and this one Quicksat intrinsic magnitudes file: qsmag.zip
我感觉到PyEphem有能力在给定起始幅度(std.mag)数的情况下进行此计算.互联网上有标准"数量级数字(不确定如何计算...但是仍然可以使用它们).
I've got a sense that PyEphem has the capability to do this calculation given a starting magnitude (std.mag) number. There are "standard" magnitude numbers available on the internet (not sure how they are calculated... but they are available none-the-less).
所以..我不确定100％的位是如何获得该角度B.我将在下一个内容中进行研究(注意:解决这个问题-请参见文章顶部)
So.. the bit I am not 100% certain on is how to get that angle B. I'll be looking at that next (note: worked this out - see top of the post)
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