April 25, 2017

Technical Issues Extending iPhemeris Ephemeris to Cover 5000 Years

Geek alert! This is a technical article about some of the issues I ran into whilst extending iPhemeris’s Ephemeris to cover a 5000 year period from 2500 BC to 2500 AD. Initially I’d thought it would be a simple matter to add a few thousand more years to the database. Devices have a lot more storage these days and network and download speeds are faster than when iPhemeris was first created. So why not, easy peasy right?! I did the work to read the JPL Ephemeris files and the USNO asteroid ephemeris over 8 years ago (both use the same format to store data) and could easily create what iPhemeris uses in any format. So creating a database that covered a longer period of time was really only a matter of a few days work and given the relative frequency of requests for more data, I thought why not just add it as an In-App purchase. It took only a few hours work to create the new tables and pull in 4 more asteroids/planetoids from the USNO Ephemeris (the more frequently requested ones): Hygiea, Astraea, Eris and Sedna. Then set about updating the various places in the iOS and MacOS versions of the code that […]