Improve Alignment Thoughts

Ways to possibly get better Alignment:

• Use compass as an input to help calculate alignment or bias.
• Discard obviously incorrect GPS.
• Throw away AR points when tracking is lost? Does ARCore / ARKit support recovery if it encounters a previously seen place?
• Use more than the latest pair of AR / GPS to calculate the alignment?
• Kalman filter "prediction" while moving, to take account of movement (same as previous point?).
• Altitude intersect with terrain or buildings to guess altitude?
• Image analysis (edge detection?) to detect horizon (& buildings?) from camera image and match so that it lines up better.
• Use point cloud from previous sessions / other devices?
• Better combination of all above inputs to an alignment than the current single-value "bias". Machine learning?