NavList:

Hello!

I'm trying to find a way to fix myself in case of a serious trouble - like all records are wet and (hopefully - temporarily) unaccessible, so no DR or very inaccurate DR because of a long storm with no proper logging being done during those days. No aliens involved, of-course! :)

The interpolated input data gives much more reasonable output than the obviously wrong input. The body₁-body₂-body₁ sight with the interpolation of body₁'s H_O to the moment of body₂ H_O put me quite close to the actual position - though I took the three "sights" one hour apart each.

2017-09-07T00:00

• GHA_Aries = 346°15.7', SHA_Vega = 80°36.9', Dec_Vega = 38°48.4', GHA_{Vega _T00:00} = 66°52.6', H_{OVega _T00:00} = 29°44.5', Zn = 297°;

2017-09-07T01:00

• GHA_Aries = 1°18.2', SHA_Capella =  280°30.3', Dec_Capella = 46°0.7', GHA_{Capella _T01:00} = 281°48.5', H_{OCapella _T01:00} = 58°42.6', Zn = 94°;
• GHA_{Vega _T01:00} = 81°55.1', Zn = 308°;

2017-09-07T02:00

• GHA_Aries = 16°20.6', SHA_Vega = 80°36.9', Dec_Vega = 38°48.4', GHA_{Vega _T02:00} = 96°57.5', H_{OVega _T02:00} = 17°58', Zn = 319°;

I "interpolated" Vega's H_O at T01:00 as: ( 29°44.5' + 17°58') / 2 = 23°51.2', that I used for the round of 7.5x formulas.

D₁₂ = 93°19.6'

A = 13°41.5'

B = 15°53,3'

Lat_A+B = 60°48.8'E

Lat_A-B = 74°55.6'E

Using the actual Vega's azimuth - I select the  Lat_A+B = 60°48.8' for the further calculations.

LHA_A+B = 112°3.7'

Lon = LHA_A+B -  GHA_{Vega _T01:00} = 112°3.7' - 81°55.1' = 30°8.5'N

I think - considering the huge time interval between the "sights" (which I choose to evaluate a "worst-case") - the fix is rather close to the position for which those H_O's were pre-calculated: the 60°N30°E.

I will try some more realistic sets of data - with reasonable inter-sight intervals of 10 minutes to see if the fix would be closer to the actual position.

Regards,

Tony