Id guess it could be done for not that much, assuming accuracy can go from a few meters to few thousands of miles. (Someone more versed might be able to give a

Id guess it could be done for not that much, assuming accuracy can go from a few meters to few thousands of miles. (Someone more versed might be able to give a better oom on accuracy). Just need to launch 4(+) satalites, 2 up and 2 down relative to the orbital plane. So long as a ship isn't hiding behind a planet/sun it should have LOS to all 4 for triangulation.