
NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: learning sight reduction
From: Bill B
Date: 2006 May 3, 21:41 -0500
Alex wrote:
> But still I think the word "challenge" does not necessary imply
> a duel. We (mathematicians) say "a challenging problem", for example,
> about a problem which attracts us.
Adjective vs. verb ;-) "I challenge you to..." vs "It is a challenge
problem."
In reality I do use a calculator quite often even when practicing 229. I
use it at least for v, d, time-to-arc, and final d correction to tabular
data. Sometimes for interpolation of Z.
With the TI-XA30 (which I consider to be more intuitive for me than the
Casio, especially for one-variable statistics) I can generally determine Hc
and Zn in 3 to 3 1/2 minutes once time, AP, GHA, SHA, declination, d and v
have been established.
General method for standard formulas/sun.
Decimal time increment in memory 1 (M1)
GHA in memory 2 (M2)
Declination in memory 3 (M3)
M1 * 15 + M2, store M2
M1 * d +/- M3, store M3
M2 +/- AP lon, store M2
Decimal lat, store M1
(Actually I just use the sum, 2nd, memory-number sequence to add or subtract
to the to the registers) Of course there are 2 extra keystrokes to convert
each set of dd/mm/ss to decimal degrees.
For Hc
sin M1 * sin M3 =, + (cos M1 * cos M2 * cos M3) =
Then 2nd sin (store in M2)
For Z
sin M3 - (sin M1 * sin M2)=, / (cos M1 * cos M2)=
2nd cos
If sin LHA (M2) positive, subtract Z from 360 for Zn
(store in M1)
In practice I run Hc at least twice before storing in M2 (little keys are
easy to mispunch). If the first two do not agree, I run it a third time.
Same with Z.
Zn is stored in M1, so I have Zn recorded in M1 and Hc recorded in M2.
When finished I can recall M1 and M2 and write it down.
I do like the ability to enter dd/mm.m in the Casio.
Bill
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From: Bill B
Date: 2006 May 3, 21:41 -0500
Alex wrote:
> But still I think the word "challenge" does not necessary imply
> a duel. We (mathematicians) say "a challenging problem", for example,
> about a problem which attracts us.
Adjective vs. verb ;-) "I challenge you to..." vs "It is a challenge
problem."
In reality I do use a calculator quite often even when practicing 229. I
use it at least for v, d, time-to-arc, and final d correction to tabular
data. Sometimes for interpolation of Z.
With the TI-XA30 (which I consider to be more intuitive for me than the
Casio, especially for one-variable statistics) I can generally determine Hc
and Zn in 3 to 3 1/2 minutes once time, AP, GHA, SHA, declination, d and v
have been established.
General method for standard formulas/sun.
Decimal time increment in memory 1 (M1)
GHA in memory 2 (M2)
Declination in memory 3 (M3)
M1 * 15 + M2, store M2
M1 * d +/- M3, store M3
M2 +/- AP lon, store M2
Decimal lat, store M1
(Actually I just use the sum, 2nd, memory-number sequence to add or subtract
to the to the registers) Of course there are 2 extra keystrokes to convert
each set of dd/mm/ss to decimal degrees.
For Hc
sin M1 * sin M3 =, + (cos M1 * cos M2 * cos M3) =
Then 2nd sin (store in M2)
For Z
sin M3 - (sin M1 * sin M2)=, / (cos M1 * cos M2)=
2nd cos
If sin LHA (M2) positive, subtract Z from 360 for Zn
(store in M1)
In practice I run Hc at least twice before storing in M2 (little keys are
easy to mispunch). If the first two do not agree, I run it a third time.
Same with Z.
Zn is stored in M1, so I have Zn recorded in M1 and Hc recorded in M2.
When finished I can recall M1 and M2 and write it down.
I do like the ability to enter dd/mm.m in the Casio.
Bill
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To unsubscribe from this group, send email to NavList-unsubscribe@fer3.com
-~----------~----~----~----~------~----~------~--~---