Plotting a linear intercept course with constant speeds 1) It must start at the shooter and intercept the target at time t: Vi (t) = Ptarget (t) - Pshooter 2) Its norm must be equal to the projectile speed * transit time, because its trajectory is linear.
Subtraction of vectors! (I think). If you do intercept, then your angle of relative velocity will have been a straight line between the two vessels - ie as if he is stationary and you have travelled straight towards him. BUT, is the interception possible (your max speed may be too slow to achieve it). Need to do this with diagrams really. It's just like plotting course to steer to allow for tide (he is tide) to reach point of intersection, using pair of compasses as other mailer here suggests.
The intercept if on shallow angle will be a long coincidental line cross - but both will see each other at sufficient distance to basically null and void the error ... In fact it would have to be pretty bad conditons and an extreme case to be really that worthy of worry.
Draw his course and speed over several hours if necessary on any chart or graph paper - making sure that orientation is related to reference lines on paper or long / lat on chart.#N#Now you draw a line with course you intend to make ... where they cross is the intercept point and distnace divided by your expected speed = time to Intercept.#N#If you want to meet at a given time ..... then mark of on his course line the location at that time ... now draw from your location to that spot - gives you distnace and course to make ... knowing time needed to get there - gives speed you need to make ...#N#If you are not fussed about location of intercept - then decide time to meet ... this gives you distnace to run at expected speed for both boats ..... set that on a pair of compass dividers his distance to make ... draw an arc from his location for his distance ... now set to your distance and draw arc from your location ..... the two will meet if its possible and that is the location ... for time and speed ....#N#Simple Triangles ...
a. The LCB BA is transferred through C, the predicted position of target B after 1 hour, to form CY.
How about drawing Boat B's course on the chart as a line and then a line at right angles to it through your point. i.e Closest approach to your starting point. That is the course. The speed is then set by finding the time Boat B will take to get to the point and applying it to Boat A distance to the point.#N#This will minimize Boat A travel distance. But assumes Boat A is ahead.#N#However, there are many possibilities. The hardest one would be finding the quickest time to intercept. Which I would guess would be an iterative solution. i.e. keep picking times and plotting where Boat B would be and drawing a position circle for Boat A at its maximum speed. If the circle crosses ahead of where boat B would be, then pick a smaller time. If behind pick a longer time.
The line cross drawing method is sufficient in 99.999% of cases. Otherwise we would not have been able to manually plot radar targets, sights, intercepts of vessels in war and peace !!