The 3.3 update for TPE for iOS was released today, with a few changes.
Updated World Magnetic Model
We updated the in-built World Magnetic Model for 2015 – 2020. Every five years, the National Geophysical Data Centre here in Boulder, Colorado and the British Geological Survey in Edinburgh, produce an updated model for how local magnetic north varies from true north.
If you enable magnetic north within the app (in Settings), then all azimuths and bearings are relative to local magnetic north. But not only that: magnetic declination varies over time too (which is why new models are required every few years). The model accounts for changes over time during the validity period (now 2015 – 2020), so TPE uses the magnetic declination for both location and date to give the most accurate result.
We’ve open sourced our iOS wrapper for the World Magnetic Model: it’s available here if you need it for your app: https://github.com/stephent/ObjectiveWMM
Visual Search is up to 80% faster
Apple has made great strides in providing improved performance measurement tools for developers. We’ve been using those tools to optimise some of the astronomical calculation code underlying TPE.
Visual Search is calculation intensive: multiple sun and moon position calculations are required, even with interpolation between results. As a result, any improvement in one of the basic calculations reaps big rewards for Visual Search.
In 3.3, Visual Search is up to 80% faster.
We’re delighted to have partnered with Skyfire to bring their sunrise and sunset color forecasting service exclusively to TPE.
Skyfire covers the lower 48 states of the USA at present, with expanded coverage planned in the future. It’s available as an in-app subscription with a 30-day free trial.
We’ll be adding Skyfire to other versions of TPE over the coming months.