03-08-2023, 07:11 AM
Hello,
Delighted to be accepted as a member of this exclusive forum.
I have been boating for more than 45 years and have decided it is high time I learned the art of Celestial Navigation. Having studied 2 books Tom Cunliffe and Mary Blewitt I feel I have a reasonable understanding of the subject, however both books use tables (AP3270) to determine the Intercept and to continue my studies I would like to be able to calculate Zn and Hc directly using a scientific calculator.
I turned to youtube and found Cram Daily PH
Formula for missing side
cos xz = cos px cos pz + sin px sin pz cos P
After much ado I discovered how to use this formula and arrived at the same answer as the example given.
Formula for angle
cos Z = - cos P cos X + sin P sin X cos Px
Not attempted this formula yet
I then discovered Chris Nolan
Formula for side
sin Hc = sin L sin D + cos L cos D cos LHA
Due to my success with the previous formula I had little trouble with this arriving at a very similar answer to the example given although I tried it to a different number of decimal places on the calculator which reveals quite different results
Chris Nolans formula for Z
cos z = sin D - sin L x sin Hc / cos L x cos Hc
Not tried this yet
I am at a very early stage regarding studying this direct method and hope to learn more from this forum.
If anyone is interested I can post my exact workings for the above
I do have a specific question but I guess this is enough of my ramblings for now.
Mike
Delighted to be accepted as a member of this exclusive forum.
I have been boating for more than 45 years and have decided it is high time I learned the art of Celestial Navigation. Having studied 2 books Tom Cunliffe and Mary Blewitt I feel I have a reasonable understanding of the subject, however both books use tables (AP3270) to determine the Intercept and to continue my studies I would like to be able to calculate Zn and Hc directly using a scientific calculator.
I turned to youtube and found Cram Daily PH
Formula for missing side
cos xz = cos px cos pz + sin px sin pz cos P
After much ado I discovered how to use this formula and arrived at the same answer as the example given.
Formula for angle
cos Z = - cos P cos X + sin P sin X cos Px
Not attempted this formula yet
I then discovered Chris Nolan
Formula for side
sin Hc = sin L sin D + cos L cos D cos LHA
Due to my success with the previous formula I had little trouble with this arriving at a very similar answer to the example given although I tried it to a different number of decimal places on the calculator which reveals quite different results
Chris Nolans formula for Z
cos z = sin D - sin L x sin Hc / cos L x cos Hc
Not tried this yet
I am at a very early stage regarding studying this direct method and hope to learn more from this forum.
If anyone is interested I can post my exact workings for the above
I do have a specific question but I guess this is enough of my ramblings for now.
Mike