prm@aquarium.ecn.purdue.edu (Phil Moyer) (07/13/89)
From: prm@aquarium.ecn.purdue.edu (Phil Moyer) In the game Harpoon, the rules state that you have a firing solution after you've taken six passive bearings. Why six? I think I can do it in four. Here's how: Take four passive bearings, each 1 minute (or whatever time period you like) apart. You know your course and speed, which you are plotting on your plotting board. From that, you can get the formulas for the bearing lines. You know that (if the target is traveling at a constant speed) your bearings divide the target's course into equal length line segments. You just calculate the formula for the line that fits that description. I have four formulas that take the formulas of the bearings as input and give you formulas for x, y, dx and dy as output, where x and y are the coordinates of the target (on your plotting board) at time t, and dx and dy are the x and y vectors of the targets velocity at time t. I'll e-mail the formulas if anyone is interested. So back to the question. Why do you need six? Is this just one of the rules of the game that hide technical details? Or do you need the extra two bearings to calculate confidence in your solution? Cheers, Phil Moyer prm@aquarium.ecn.purdue.edu