Navigation
Determining Latitude using Polaris (the Pole Star)
Most of us are aware of the significance of the Pole Star (North Star), correctly called Polaris.
It sits over the North Pole, on the axis of the earth. In the Northern hemisphere we are very lucky, as it will always shows us where true north is (providing the sky is clear!)
But there is more to Polaris than showing us north. Consider the diagram below;
Read more: Determining Latitude using Polaris (the Pole Star)
'Backbearing' and free downloadable tables
The normal book requirement for Astro-Navigation is a current Nautical Almanac and Sight Reduction Tables. Regardless of expense, they are also a fairly hefty set of 'tomes' to have to cart around with you.
This year I have been using some free tables downloadable from an excellent website called 'Backbearing' Not only can you download this years Nautical Almanac, but you can also download sections of Sight Reduction Tables (SRT). Rather than having to download all latitudes, this convenient website allows you to download the SRT's in 7 degree blocks.