News about the almanac

[Karen K]

There was a discussion some weeks ago about PyEphem becoming outdated and replaced by Skyfield. It resulted in making the WeeWX almanac extensible and providing an installable WeeWX extension based on Skyfield. This was done because Skyfield has more dependencies than PyEphem, and we did not want to add new dependencies to core WeeWX. The extension not only replaces the PyEphem based almanac, but also provides some additional attributes and events like:

• solar date and time
• apsides (the events when they take place)
• Venus and Mercury phases
• which constellation a star or planet is in
• additional attributes for heavenly bodies

For a list of differences see PyEphem vs. Skyfield.

Additionally there is a second extension based on the first one which provides an actual sky map for the location of the weather station with Sun, Moon, the planets, stars, and -configurable - Earth satellites, as well as a symbol of the moon with realistic phase, and an analemma.

Extensibility of almanacs will come with WeeWX 5.2. If someone is in the mood of testing the almanac beforehand, please, get the almanac.py file out of the development branch of WeeWX and copy it into an actual installation. Then the new extensions can be installed. Here are the links:

• weewx-skyfield-almanac
  
• weewx-skymap-almanac
  

Both are still under development. Feedback will be appreciated.