# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

**Celestial Navigation Made Easy - by Francois Meyrier**

**From:**J Cora

**Date:**2009 Apr 24, 11:41 -0700

I got this book some time ago and recently got back to it. The book is subtitled Using a Pocket Calculator and the author recommends the casio fx-115MS. I purchased the same model about a year ago but was unable to figure out how to use the device, partially due to a very poor manual but also due to a reluctance to mash around the keys. Recently I came across this web tutorial on the calculator http://faculty.ccc.edu/jnadas/graduate/CASIO.fx115ms.HTM Which prompted me to try the formulas on page 34 of the book. I am now pleased with the calculator and also I recall it was inexpensive. I won't go into all the details of entering coordinates but I am attaching a text document on how to enter the formulas which has been lightly proofread. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To unsubscribe, email NavList-unsubscribe@fer3.com -~----------~----~----~----~------~----~------~--~--- ------------------------------------------------------------- Usage of Casio fx-115MS to calculate Hc and Zc {- minus} the black minus key {x times} the black multiply/times key {% div } the black divide key {SHIFT} the brown SHIFT key at top left {ALPHA} the red alpha key located next to shift {CALC} the grey calc key if SHIFT is pressed first then it is the SOLVE = key or if ALPHA is pressed first then it is the = sign when entering a stored equation {Ans} press the black Ans key this key stops the calculator from recalculating new values so the result of operations can be stored in registers. Notes: When you see something like {ALPHA} A below It means press the {ALPHA} key followed by the {CALC} key. The A is printed above the {CALC} key in red meaning press {ALPHA} first. I chose not to use {ALPHA} {CALC} as it seemed confusing and once the sequence of key presses is understood is goes very quickly. The same goes for {SHIFT} with the second key the text in brown. ------------------------------------------------------------- Altitude sin HC = sin Lat sin decl + cos Lat cos decl cos LHA Format A B C calculator {sin} {ALPHA} A {X times} {sin} {ALPHA} B {+} {cos} {ALPHA} A {X times} {cos} {ALPHA} B {X times} {cos} {ALPHA} C {ALPHA} {CALC} {ALPHA} X {SHIFT} {CALC} A? value in A register press the {=} black key B? value in B register press the {=} black key C? value in C register press the {=} black key X? {SHIFT} {CALC} should display X= sin Hc value {Ans} {SHIFT} STO Y store value in Y {SHIFT} {sin} {ALPHA} Y {=} should display sin-1 Y and Hc value in degrees {SHIFT} STO D store value in D register ------------------------------------------------------------- Azimuth cos angle Z = sin decl - (sin Lat sin Hc ) / ( cos Lat cos Hc ) Zc = Z if 180 deg < LHA < 260 deg Zc = 360 - Z if 0 deg < LHA < 180 deg {sin} {ALPHA} B {- minus} {(} {sin} {ALPHA} A {X times} {sin} {ALPHA} D {)} { % div} {(} {cos} {ALPHA} A {X times} {cos} {ALPHA} D {)} {ALPHA} {CALC} {ALPHA} X {SHIFT} {CALC} A? value in A register press the {=} black key B? value in B register press the {=} black key C? value in C register press the {=} black key X? {SHIFT} {CALC} {SHIFT} {cos} {ALPHA} Y {=} should display cos-1 Y and Z value in degrees {SHIFT} STO E store value in E register Zc is calculated from given rules