Given the coordinates of three observers ($i,j$ and $k$) and the velocity, $v$, of some signa, I'd like to calculate the maximum possible time of arrival difference for all possible combinations of the three observers in the case a) where we can assume the three observers and the source are coplanar, and b) where the three observers and the source lie in a 3-dimensional space.
That is, where signal source can be at any point in plane, I want to calculate the maximum possible values for (time of arrival at $i$ - time of arrival at $j$), (time of arrival at $i$ - time of arrival at $k$), etc.
Intuitively, I would've thought that this should simply be the straight line distance over $v$, however I know that not to be the case.
Please, feel free to edit the tags used here. I wasn't quite sure what would be most appropriate for this question.