如何从PyEphem获取物体的地球惯性或地球中心坐标? [英] How to get earth-inertial or earth-centered coordinates of objects from PyEphem?

问题描述

我想获取各种 XYZ 坐标中的对象的坐标，而不是它们出现在天空中的位置.我感兴趣的是:

I would like to get coordinates of objects in various XYZ coordinates, not where they appear in the sky. I'm interested in:

1. ECE:"以地球为中心 惯性" (不随地球旋转)

1. ECE: "Earth Centered Inertial" (not rotation with the earth)

ECEF:"以地球为中心 固定在地球上"(不是惯性的， 叫做以地球为中心的旋转"

ECEF: "Earth Centered Earth-Fixed" (not inertial, also called "Earth Centered Rotational"

和某种太阳系或黄道坐标(太阳或 重心居中).

and some kind of solar system or ecliptic coordinates (sun or barycenter centered).

我已经安装了PyEphem，运行了一些示例，并开始了解内幕，但是到目前为止，我发现的示例似乎集中于天空中事物的出现方式.

I've installed PyEphem, run a few examples, and have started to understand what's under the hood, but so far the examples I've found seem to focus on how things appear in the sky.

链接到有用的操作方法"或简单的示例都将有所帮助.现在，我看不到标准选项在哪里:

Either a link to a useful "how to" or a simple example would be helpful. Right now I don't see where to go with the standard options:

In [55]: mars.
mars.a_dec              mars.g_dec              mars.radius
mars.a_epoch            mars.g_ra               mars.rise_az
mars.a_ra               mars.hlat               mars.rise_time
mars.alt                mars.hlon               mars.set_az
mars.az                 mars.hlong              mars.set_time
mars.circumpolar        mars.mag                mars.size
mars.compute            mars.name               mars.sun_distance
mars.copy               mars.neverup            mars.transit_alt
mars.dec                mars.parallactic_angle  mars.transit_time
mars.earth_distance     mars.phase              mars.writedb
mars.elong              mars.ra

In [55]: mars.

推荐答案

PyEphem是其包装器的旧C库不会，总是使用( x ， y ， z )在内部进行协调，并且这样做时不会公开它们，以便Python可以看到它们是什么-( x ， y ， z )坐标就会被丢弃.

The old C library that PyEphem is a wrapper around does not, alas, always use (x, y, z) coordinates internally, and when it does it does not expose them so that Python can see what they were — the (x, y, z) coordinates are discarded once the angles have been computed.

对于同一作者(刚好是我！)的一个较新的天文学库，该库已被完全重写，以使( x ， y ， z )的坐标确实在每个步骤中都可用，请尝试看看Skyfield:

For a newer astronomy library by the same author (as it happens, me!) that has been completely rewritten so that (x, y, z) coordinates are indeed available every step of the way, try taking a look at Skyfield:

http://rhodesmill.org/skyfield/

尤其要研究.position.km和.position.au之类的属性如何让您获得任何位置并将其分解为( x ， y ， z )笛卡尔坐标:

In particular, look at how attributes like .position.km and .position.au let you get any position and decompose it into (x, y, z) Cartesian coordinates:

http://rhodesmill.org/skyfield/positions.html

这篇关于如何从PyEphem获取物体的地球惯性或地球中心坐标?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！