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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextants in Coastal Piloting
From: Richard B. Emerson
Date: 2000 Aug 28, 5:54 AM
From: Richard B. Emerson
Date: 2000 Aug 28, 5:54 AM
???! Although I haven't cruised the lower Bay this summer (we went north to New England, instead), I have never experienced 20 mile errors with or without differential receivers while cruising from the Annapolis area as far south as Waterside in Norfolk. For that matter, I have never experienced 20 mile errors anywhere from Seattle to Grand Cayman to Frankfurt, Germany, using a simple Magellan 300 handheld receiver. LORAN has been consistently less geodetically accurate. TD's converted to L/L's and even TD's observed compared to their charted intersection have been typically 1/4 to 1/2 mile away from the receiver's true location although, until S/A was disabled, repeatability (returning to a previous TD or L/L fix) was as good or better than GPS. Rick S/V One With The Wind, Baba 35 Young, Derrick writes: > Russell, > > I am not sure what is happening with the GPS in some areas. There are (that > might be were - at least when S/A was turned on) areas where GPS would > indicate as much as 20 miles off. One of these areas was the lower > Chesapeake Bay and another in St. Louis. If you were piloting using GPS, > you were in trouble. So, break out the LORAN (that still works) or the > sextant. Take your horizontal angles and you know where you are. > > The reason that I am not sure is the current status, is that I have not been > out on the C'Bay since S/A was turned off - I will be going out in the next > couple ow weeks - will let you know what I find. [...]
