Originally Posted by
Recc
Those figures are for waterline visibility. If you add in the height of the ship, then they look more realistic (e.g. a periscope at a height of 20ft can see a 70ft warship out to 13Nm.
On the wider point, target-motion analysis as a method for estimating range from passive sensors has been around in crude form since before the 2nd world war. On modern submarine with automated analysis it is much more sophisticated.
Thanks. Makes sense. I had a feeling there were ways to get range as well as bearing from passive sonar, just didn't know how it was done. Presumably modern signal processing makes that easier and more accurate.