NavList:

Thanks Frank,

I agree with  you re the modern time sight. I still use the intercept LOP method, mostly because I enjoy using the Bygrave and Browne Nassau which are set up for that. If I am going to use calculators, however, I've discovered that a "relatively cheap" Casio fx-3650P can take up to 4 cel nav programes, then this works best for me. Far less mistakes from pressing the wrong buttons. Just 3- 6 basic inputs.

One of my favourites is the 2 body simulataneous time sight which gives lat and long direct.

Simultaneous Time sights for Long and Lat. Formulae from Karl page 78-79 (131 bytes)

Inputs: d₁(>A) and d₂(>B)_. Dec of the 2 bodies.

GHA₁ (>C)and GHA₂ (>D) GHA of the 2 bodies

H₁ (>X) and H₂ (>Y) Alts of the 2 bodies.

Find D₁₂ = great circle GP₁-GP₂

1)Cos D₁₂=sind₁sind₂+cosd₁cosd₂cos(GHA₁-GHA₂)

?>A:?>B:?>C:?>D:?>X:?>Y(sinAsinB)+(cosAcosB)cos(C-D):cos^-1Ans>M:

1)      Cos B=(sinH₂-cosD₁₂sinH₁)/sinD₁₂cosH₁

(sinY-cosMsinX)/sinMcosX: Cos^-1Ans>Y:

2)      Cos A=(sind₂-sind₁cosD₁₂)/cosd₁sinD₁₂

(sinB-sinAcosM)/CosAsinM:cos^-1 Ans-Y:Ans>Y:

3)      Sin Lat=sind₁sinH₁+cosd₁cosH₁cos(A-B) (Cos (A-B) now in Y)

sinAsinX+CosACosXCosY: sin^-1Ans>Y:

4)      Cos LHA₁=(H₁-sind₁sinLat)/cosd₁cosLat

(sinX-sinAsinY)/CosACosY:Cos^-1Ans-C:Ans

5)      Lon=LHA₁-GHA₁

EG1

Dec 1=75˚>A. Dec2=30˚>B.GHA1=30˚>C, GHA2=320˚>D, H1=60˚>X, H2=45˚>Y.

Gives answer Lat 68˚31’N , long 80˚17’ (East+ and west-)

EG2

Dec1=7˚24.4’N, Dec2=-11˚7.7’S,GHA1=37˚52.9’, GHA2=285˚23’,H1=30.3861˚, H2=20.77519˚. Gives Ans Lat35˚, long 20˚.

My ideal is a "no clock" "simultaneous" moon- sun fix and lunar for GMT. 

Recently, I've  used the Bygrave for the 2 LOPs and the Fuller 3 for the lunar GMT, using your version of the Thompson abbreviated clearance method.(Also the occassional Margett graph clearance, just for fun). Both are now pre-programed on my Calculator and give virtually instant accuracy check on my slide rule and Margetts calculations. Great fun.

Best wishes

Francis