sattools/README.md

Giza Sattools

Current state: it works, mostly. See above screenshot from port.

sattools

This is a fork of cbassa's sattools to try to get it to work with free software giza instead of proprietary and unmaintained pgplot.

Install

In Debian: libgiza0 giza-dev etc.

Giza

Here are two examples of how skymap should render, in this case using pgplot (thx Pierros and Cees):

This is how skymap renders "out-of-the-box" using giza as a drop-in replacement for pgplot:

Stars fix:

Text fix:

Rectangle fix, and grey:

More pgplot colors.

Giza sizing needs fixing...

SatNOGS TLE loads and renders.

There is an error that spams out to the console:

%giza - Warning - giza_set_character_height: Invalid character height, character height not set

The character heights are set to various values, typically 0.6, 0.8, and 1.0. Only 1.0 doesn't produce the error. But it renders much larger... This has no errors, but looks bad. Overall need new font.

Satellite orbit lines rendering.

More, but not rendering so great...

Grid, but rendering with dots, not lines...

Rest of grid (blue background during day).

Equatorial. Hit o when skymap first launches, then it will re-render with a faint equatorial "dot line circle"...

Remove broken constellations looks better for now.

fix orbit lines, maybe correct. need to confirm against main version.

Revert back to original size. Pierros has larger window somehow...

Works

Testing/dev in Debian Bookworm (testing), with giza version 1.3.2.

Out of box, this works:

• Sun.
• Moon.
• Besides the display, all the other functionality works. Can load a satnogs.tle, get satellite info, schedule, etc.

Fixed

• Stars.
• Text header with date, observer, lat/lon/elevation.
• Footer with R, D etc.
• Rectangle.
• Apex renders, but as dots not lines.
• Grid renders, but as dots not lines.
• Satellites' colors.
• Orbit lines.
• FOV (but disabled by default upstream).

TODO

• Lines are dots not lines.
• Small window size with giza.
• Constellations only partially rendered. Disabled.
• Apex rendering needs adjusting.
• Check license status of sgdp4.c and sgdp4h.h.
• Font.

Functions

These are pgplot functions used by skymap.

cpgbox
cpgcirc
cpgconl
cpgcont
cpgcurs
cpgdraw
cpgend
cpgeras
cpgmove
cpgmtxt
cpgopen
cpgpap
cpgpt1
cpgqch
cpgqci
cpgqls
cpgrect
cpgsch
cpgsci
cpgscr
cpgsfs
cpgsls
cpgslw
cpgsvp
cpgtext
cpgwnad

Color

Colors 1-15 are used in the color index, documented here:

• https://sites.astro.caltech.edu/~tjp/pgplot/fig51.html

Colors are off because giza uses it's own palette by default. What is needed is to add giza.h and set this to use pgplot colors:

giza_set_colour_palette(1);

Satorbit

The satorbit has the same issues as skymap.

Here is what it looks like out-of-the-box with Giza:

Upstream

See README-upstream.md.

Sattools:

• https://github.com/cbassa/sattools

Giza:

• https://danieljprice.github.io/giza

License

Same as upstream license, GPLv3.

Copyright (C) 2022, Jeff Moe