I've been writing a story about faster than light travel and trying to stay within the boundaries of what Einstein's worshipers believe is possible.
There are three basic parts of the system:
The first is a long range scanner capable of detecting even tiny space debris traveling at speed.
The second is a camera system which records star positions and identifies them using spectroscopy. This allows the ship to maintain a record of its position relative to a location. This becomes tricky, more on that later.
The third is a "wormhole" projector. Yeah, I know, this sounds kind of wacky. Essentially the ship projects a wormhole that allows it to travel as far as the scanner system can see in an instant. Lets say 1,000,000 kilometers or 600,000 miles.
Once the ship makes a jump the scanners identify the exact position based on relative position of the stars. The reason this is tricky is that traveling 600,000 miles creates a slight difference in the way we see things.
At 100 meters, a one degree variation results in about 25mm of variation. A kilometer, 250mm of variation. 10 kilometers, 2500 or 2.5 meters. 10,00,000 is 250,000 meters. Precision becomes very important in relative location, and after jumping what is, essentially, 3 light seconds, everything moves.
While the rear scanners are locating the ship precisely, the forward scanners are scanning for any space debris that could cause problems. If the space is clear, another worm hole is projected and the ship jumps.
The velocity of the ship is based on the time it takes to calculate and the range of the mass scanners. The faster the processing, the further the scanning range, the faster the velocity. 3 seconds scanning at about 1 million kilometers is light speed. 1 second at 1M is 3xL.S. .1 second is 30xL.S.
Anyhow, still working on it.