Images:

1. Credit/Permission: © David Jeffery, 2013 / Own work.
   Image link: Itself.
   
2. Credit/Permission: © David Jeffery, 2019 / Own work.
   Image link: Itself.
   

Local file: local link: declination_altitude.html.
Extended file: Celestial sphere file: declination_altitude_4.html.
File: Celestial sphere file: declination_altitude.html.