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Re: The "Death to the Intercept Method" revisited?
From: Andrés Ruiz
Date: 2017 Sep 25, 15:43 +0200
From: Andrés Ruiz
Date: 2017 Sep 25, 15:43 +0200
Dear Jing,
--
I am afraid you have misunderstood the Metcalf method described in Advancing Celestial Circles of Position
The angles Thetalong and ThetaLat (thetaGHA, thetaDec in your notation), are for rotating the vector from GP(t1) to GP(t2)
regards,
2017-09-21 7:43 GMT+02:00 Jing C <NoReply_JingC@fer3.com>:
Whoops, forgot to add that "D" needs to be divided by 60. Attaching updated version. Also, another reference used (Mainly for the requirements for setting sight 1 and 2) is:Gery, Stanley W. "The direct fix of latitude and longitude from two observed altitudes." Navigation 44.1 (1997): 15-24.On Wed, Sep 20, 2017 at 10:08 PM, Jing C <NoReply_JingC@fer3.com> wrote:To go back to Tony's original question, I think there is a way to do the running fix with a direct calculation method using a calculator but not plotting. I have attached a work form that I've created, four forms to a sheet.
References:
- Celestial Navigation in the GPS Age by John Karl
- METCALF, T. R. (1991), Advancing Celestial Circles of Position. Navigation, 38: 285–288. doi:10.1002/j.2161-4296.1991.t
b01861.x
Attached File:
Direct-Position-Calculation-Form-Doubled-Up.pdf
Attached File: 140105.direct-position-
calculation-form-doubled-up.
