Quick build doc

README.md

@@ -42,13 +42,27 @@ The following (mis?)-features have been added to `skymap` in the active
   (Are the binary apps needed elsewhere?)
 
 
-# Install
-In Debian: `libgiza0 giza-dev` etc.
+# Build
+Development is done in Debian Bookworm (testing).
+
+```
+sudo apt install giza-dev git make dos2unix source-extractor wcslib-dev \
+     libgsl-dev gfortran libpng-dev libx11-dev libjpeg-dev libexif-dev
+
+git clone https://spacecruft.org/spacecruft/sattools
+
+cd sattools/
+
+make
+```
+
+Built files get put in the `bin/` directory.
 
 
 # Usage
 ```
-$ ./skymap --help
+cd bin/
+./skymap --help
 Usage: skymap [OPTION]
 Visualize satellites on a map of the sky.
 
@@ -59,8 +73,8 @@ Visualize satellites on a map of the sky.
 -D, --decl    Decl. [+dd:mm:ss.ss]
 -A, --azimuth    Azimuth (deg)
 -E, --elevation    Elevation (deg)
--w, --width    Screen width
--g, --height    Screen height
+-w, --width    Screen width (default: 1024). Set height too.
+-g, --height    Screen height (default: 768). Set width too.
 -n, --nmax    nmax line resolution/speed (default 128)
 -S, --all-night    All night
 -Q, --no-stars    No stars