A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Robert VanderPol II
Date: 2017 Aug 13, 16:48 -0700
I never used LORAN but I was unhappy to see it go 10yr ago for reasons that are becoming appaent generally. Chertoff really screwed this one.
My understanding is that the theoretical calculation of what the TDs should be for any given location weren't very good so there was significant variance between reported location and actual location for LORAN in underway conditions.
For waypoints that had been established by actually visiting the location and recording the TDs, repeatability was on the order of 10-20m which was better than GPS when initially rolled out with SA enabled.
Because of the higher power available to landbased LORAN antennae, they are harder to jam. I don't know about spoofing.
In dealing with the effects of a Solar Flare or Coronal Mass Ejection (CME), because of the higher power, LORAN will cut out later than GPS and cut back in sooner. How much sooner or later will depend on the specifics of the event. One consideration is that a CME has the potential to damage or disable satellites. An event that damages satellites likely will damage the electrical grid. Damage to LORAN equipment is also possible due to the long conductors involved in the antennae and the feed lines. If it is just a current or voltage spike it may be that fuses are all that will be affected and the LORAN will be up an running as soon as the fuses are replaced.
Re: GPS spoofing for real
From: Mark Coady
Date: 2017 Aug 13, 09:36 -0700