PP3 -- Celestial Chart Generation

Torsten Bronger

This project is currently inactive. If you want to pick it up, send me an email.

1	Motivation
2	First overview
3	Examples
4	Documentation
	4.1	Manual
	4.2	Reference card
	4.3	Wikipedia example scripts
	4.4	Source code
5	Prerequisites
6	Original data bases
7	Imprint

Abstract

PP3 creates celestial charts. It generates resolution independent maps of very high graphical quality. They can be used for example as illustrations in books or on web pages. You may use own databases or free ones from the Internet.

PP3 has got a comprehensive user manual!

PP3 is used for the maps of all constellations on Wikipedia! (For example, have a look at the Cygnus entry.)

Before you download PP3, please have a look at the release notes.

1 Motivation

You can find very many programs on the Internet or elsewhere that draw star charts. Most of them try to imitate a planetarium or the eyepiece view. However sometimes one needs such charts for presentational purposes, and the number of stars or info pop-up windows with distances or diameters are not important. For example books have a high typographic standard normally, and most chart programs would produce output that does not do justice to it.

Here PP3 comes into play. It produces charts that may not be rich enough in detail for the professional astronomer but they are perfect as illustrations.

2 First overview

First of all, if you are interested, you can get it on PP3's project page. There you also find a reference card, a bug report system and a help forum. Its licence is a slightly modified MIT licence. But it's free software through and through.

The program itself consists only of one executable file and a data files directory. The program takes a small text file as input and produces a LaTeX, Postscript, or PDF file.

3 Examples

Figure 1:The default chart, plus some names. Please have a look at a larger view, too.

Figure 1 shows more or less the default view of PP3, i.e. if you don't change very much. Thus the input script is very short:

filename output ori.tex
switch eps_output on

objects_and_labels

delete NGC 1973  NGC 1975 ;
reposition ORI 34 E ;    # Mintaka
reposition ORI 50 W ;    # Alnitak

This is just a little bit of fine-tuning. I only have to delete some nebulae (one of them is a real duplicate in the NGC catalogue), and I have to position two labels because the constellation lines supresses them.

The Scorpion. (You may click on the pictur... (Click for original bitmap)

Figure 2:The Scorpion. (You may click on the picture to get a larger view.)

Table 1:Vector variants of the above example maps for download.
constellation	format	size


Orion	PDF	1115 kB
	EPS (gzip'ed)	255 kB
Scorpion	PDF	830 kB
	EPS (gzip'ed)	187 kB

The following script is more complex. It produces figure 2:

# Chart of the Scorpion, printable on a black
# and white printer

set constellation SCO
set center_rectascension  17
set center_declination   -30
set grad_per_cm            4.5
set box_width              9
set box_height             7

switch milky_way on
switch eps_output on
switch colored_stars off
color stars 0 0 0
color nebulae 0 0 0
color background 1 1 1
color grid 0.5 0.5 0.5
color ecliptic 0.3 0.3 0.3
color constellation_lines 0.7 0.7 0.7
color labels 0 0 0
color boundaries 0.8 0.8 0.8
color highlighted_boundaries 0 0 0
color milky_way 0.5 0.5 0.5

filename output test.tex


objects_and_labels

delete M 18  M 4  NGC 6590  NGC 6634  IC 4700 ;
reposition SCO 20 S ;    # sigma SCO
reposition M 23 NE ;

Most of the commands change colour to get this black-and-white effect. In order to savour the maps fully you must see them as vector files, see table 1.

4 Documentation

4.1 Manual

PP3's manual comes in three flavours: As a multiple-file HTML (also as a ZIP file), a single file HTML, and a PDF.

4.2 Reference card

As already mentioned, there is a neat reference card. It can be downloaded for A4 and letter paper in PDF and PostScript format. If you fold it twice to a zigzag, it's very handy, too. :-)

4.3 Wikipedia example scripts

PP3 is responsible for the star maps of all 88 constellations on English Wikipedia, the free encyclopedia. Since they can serve very well as examples, all of their source scripts are included in PP3's distribution, together with all associated files.

4.4 Source code

The source code itself is documented in detail. Please don't be afraid – the program is written in CWEB, so it's full of “human language” explanations, and rather easy to read. The source is structured so that all relevant information can be found on the first pages. There one finds a short introduction with an example and references within the source code where to get further info. If someone wants to contribute, contact me.

5 Prerequisites

PP3 creates a LaTeX file with the extension .tex. Apparently you cannot directly do something with it. So you also need:

LaTeX:

For Windows, you may want to use the MikTeX distribution, or the TeX Live distribution. For Linux, it is either already installed or you can easily install it with your package manager. This enables you to use two important commands:

latex for transforming the .tex file to a .dvi file.
dvips for transforming the .dvi file to a Postscript or EPS file.

PP3 can call these programs for you if you wish.

Ghostscript:

This is a program for viewing and printing Postscript files, and for converting them to PDF. You need Ghostscript itself and GSView. For Linux these programs are highly probably already installed.

It may seem to be unfortunate that you have to install all these programs only in order to use PP3 but fortunately the installation procedures are pretty easy and the programs are very useful also for many many other purposes.

6 Original data bases

PP3's standard distribution bases on the following original data compilations:

class of object(s)	data base name	authors of compilation


stars	BSC	Hoffleit & Warren
nebulae	NGC/IC	Wolfgang Steinicke
boundaries	Cat. of Constell. Boundary Data	Davenhall & Leggett
Milky Way	Sky Panorama View	Axel Mellinger

7 Imprint

The author of this text and of PP3 is Torsten Bronger. The name `PP3' is an abbreviation of “Parvum Planetarium” (Latin for “Little Planetarium”), version 3. The first two versions were totally different and are missing. PP1 was a project during the author's adolescence, PP2 never made it beyond the logo screen.

This document was created with the XML authoring tool tbook.

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