<p><a href="https://en.wikipedia.org/wiki/Equirectangular_projection" rel="nofollow noreferrer">Equirectangular</a>
or equidistant cylindrical projection
is the simplest way to meet these requirements.
Plate Carrée is the case where distortion is minimal at the equator.
Dominic Ford's <a href="https://in-the-sky.org/data/constellations_map.php" rel="nofollow noreferrer">Map of the Constellations</a> uses it,
as do the <a href="https://svs.gsfc.nasa.gov/3895" rel="nofollow noreferrer">Deep Star Maps</a>
by Ernie Wright of the NASA Scientific Visualization Studio.
In free software,
<a href="https://sites.google.com/site/stellariumuserguide/sky-and-viewing-options#TOC-Projection" rel="nofollow noreferrer">Stellarium</a> calls it "Cylinder," and
<a href="https://www.ap-i.net/skychart/en/documentation/chart_coordinates#projection" rel="nofollow noreferrer">Cartes du Ciel</a> calls it "Cartesian."
If you plot your own, you could scale the horizontal dimension by
$\cos 30^\circ \approx 0.866$ to minimize distortion at
$\pm30^\circ$ declination.</p>

<p>Since you are not plotting the polar regions,
other <a href="http://www.progonos.com/furuti/MapProj/Normal/ProjCyl/projCyl.html" rel="nofollow noreferrer">cylindrical projections</a> are possible.
The <a href="https://en.wikipedia.org/wiki/Mercator_projection" rel="nofollow noreferrer">Mercator</a>
projection is available in both Stellarium and Cartes du Ciel.
Stellarium also offers the
<a href="https://en.wikipedia.org/wiki/Miller_cylindrical_projection" rel="nofollow noreferrer">Miller cylindrical</a> projection.</p>

CC BY-SA 4.0
2018-06-15T09:01:16.277Z
Sorry I never responded sooner, but Cartes du Ciel did this perfectly :) Thank you!
Airgiraffe
CC BY-SA 3.0
2018-03-05T05:30:19.850Z
2018-03-05T05:30:19.850Z
Mike G
<p>You'd be converting some images from spherical coordinate system to cartesian coordinate systems. </p>

<p>You can find a texture mapping environment which can do the maths for you. I'd use Unity3D. You are converting spherical coordinate graphs to XY graphs. I think polar is XY and spherical does distance from origin so XYZ, X is the lattitude, Y the longitude. <a href="https://www.google.fr/search?q=program%20to%20convert%20spherical%20textures&amp;oq=program%20to%20convert%20spherical%20textures&amp;aqs=chrome..69i57j69i64.9216j0j9&amp;sourceid=chrome&amp;ie=UTF-8" rel="nofollow noreferrer">perhaps check this</a>. </p>

<p>The equations are 1 line of code. I learnt it myself having had 2/10 at my school maths exams. it's a copy/paste kind of equation written in every programming language. It's vaguely rated to orthographic projection. </p>

<p>You can say you are doing the inverse of spherical texture mapping. </p>

<p>You can search for resources to convert the map of the earth to and from a sphere and a square.</p>

<p>You can check cubemap.skybox projection. </p>

<p><a href="https://www.google.fr/search?q=spherical+texture+mapping&amp;num=100&amp;source=lnms&amp;tbm=isch&amp;sa=X&amp;ved=0ahUKEwjH1MqnjYDZAhUHJuwKHTuhCUwQ_AUICigB&amp;biw=1034&amp;bih=546" rel="nofollow noreferrer">spherical texture mapping</a></p>

<p>You will probably find many many programs that can do it, mathsworks, unity3d, blender, mathcad, texture mapping apps for games designers and cartographers, and they'll have different memory management, image conversion from bitmap/rgb32 and so forth and you'd find which is ok for your images. </p>

CC BY-SA 3.0
2018-01-30T16:29:46.737Z
2018-01-30T16:34:59.577Z
2018-01-30T16:34:59.577Z
bandybabboon
<p>I'm trying to find/create a star map between the declinations of -45 to +60, and need it to be a rectangle. Is there any software/website that would let me create this? Is there a name for this kind of map/projection?</p>

<p>(I've attached a diagram to try and make myself clearer) 
<a href="https://i.sstatic.net/stJsC.png" rel="noreferrer"><img src="https://i.sstatic.net/stJsC.png" alt="enter image description here"></a></p>

<p>Thanks for any help :)  </p>

CC BY-SA 3.0
2018-01-25T14:33:07.560Z
Isn't this just a Plate Carrée, or simple cylindrical, projection: turn the declination into the y-coodinate, the right ascension the x-coordinate?
Anders Sandberg
<star><fundamental-astronomy>
Creating a rectangular star map
Airgiraffe
# Creating a rectangular star map

(Asked by: username_0 on 2018-01-25)

I'm trying to find/create a star map between the declinations of -45 to +60, and need it to be a rectangle. Is there any software/website that would let me create this? Is there a name for this kind of map/projection?

(I've attached a diagram to try and make myself clearer)
[![enter image description here](https://i.sstatic.net/stJsC.png)](https://i.sstatic.net/stJsC.png)

Thanks for any help :)

**Tags:** star, fundamental-astronomy
> **Comments:**
> **username_1**: Isn't this just a Plate Carrée, or simple cylindrical, projection: turn the declination into the y-coodinate, the right ascension the x-coordinate?  

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## 2 answers

### Answer by username_2 on 2018-03-05. Score: 3 | Accepted answer

[Equirectangular](https://en.wikipedia.org/wiki/Equirectangular_projection)
or equidistant cylindrical projection
is the simplest way to meet these requirements.
Plate Carrée is the case where distortion is minimal at the equator.
Dominic Ford's [Map of the Constellations](https://in-the-sky.org/data/constellations_map.php) uses it,
as do the [Deep Star Maps](https://svs.gsfc.nasa.gov/3895)
by Ernie Wright of the NASA Scientific Visualization Studio.
In free software,
[Stellarium](https://sites.google.com/site/stellariumuserguide/sky-and-viewing-options#TOC-Projection) calls it "Cylinder," and
[Cartes du Ciel](https://www.ap-i.net/skychart/en/documentation/chart_coordinates#projection) calls it "Cartesian."
If you plot your own, you could scale the horizontal dimension by
$\cos 30^\circ \approx 0.866$ to minimize distortion at
$\pm30^\circ$ declination.

Since you are not plotting the polar regions,
other [cylindrical projections](http://www.progonos.com/furuti/MapProj/Normal/ProjCyl/projCyl.html) are possible.
The [Mercator](https://en.wikipedia.org/wiki/Mercator_projection)
projection is available in both Stellarium and Cartes du Ciel.
Stellarium also offers the
[Miller cylindrical](https://en.wikipedia.org/wiki/Miller_cylindrical_projection) projection.

> **Comments:**
> **username_0**: Sorry I never responded sooner, but Cartes du Ciel did this perfectly :) Thank you!  

---

### Answer by username_3 on 2018-01-30. Score: 0

You'd be converting some images from spherical coordinate system to cartesian coordinate systems.

You can find a texture mapping environment which can do the maths for you. I'd use Unity3D. You are converting spherical coordinate graphs to XY graphs. I think polar is XY and spherical does distance from origin so XYZ, X is the lattitude, Y the longitude. [perhaps check this](https://www.google.fr/search?q=program%20to%20convert%20spherical%20textures&oq=program%20to%20convert%20spherical%20textures&aqs=chrome..69i57j69i64.9216j0j9&sourceid=chrome&ie=UTF-8).

The equations are 1 line of code. I learnt it myself having had 2/10 at my school maths exams. it's a copy/paste kind of equation written in every programming language. It's vaguely rated to orthographic projection.

You can say you are doing the inverse of spherical texture mapping.

You can search for resources to convert the map of the earth to and from a sphere and a square.

You can check cubemap.skybox projection.

[spherical texture mapping](https://www.google.fr/search?q=spherical+texture+mapping&num=100&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjH1MqnjYDZAhUHJuwKHTuhCUwQ_AUICigB&biw=1034&bih=546)

You will probably find many many programs that can do it, mathsworks, unity3d, blender, mathcad, texture mapping apps for games designers and cartographers, and they'll have different memory management, image conversion from bitmap/rgb32 and so forth and you'd find which is ok for your images.


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