NavList:

Mike,

In reply your post just hereunder, as it seems that you got briefly confused at interpreting one angular value, may I suggest the following to our community ?

When we transcribe angles, such as Lat / Long, we could either :

write them according to the full traditional/classical way, such as : N30�13'2 W081�52'3 (or N30�13'13" W081�52'16"), or :

if we use tenths of arc minutes instead of arc seconds - which has nowadays become most usual navigational practice -, we could as well use the Civilian Aviation Format (this the one I am using to enter coordinates in our Honeywell Flight Management Computers) through entering such coordinantes as : N3013.2W08152.3
Such format is quite compact. It also eliminates the use of ' (arc minute symbol) which I sometimes cannot get to show up correctly in the NavList Forum posts. It can also be easily extended if more significant figures are required : N30�13'13" W081�52'16" will then show up as N3013.217W08152.267

If using this specific aviation code, the height quoted by Paul would then have been 4026.2 (or 40�26'2 in its classical transcription) while using the 40.262 figure would imply decimal degrees (which was you initial and early guess).

This is just a suggestion and an idea in the air ... What do you think, my Fellow Maritime Navigators about such an aviation format ?

Best Regards from

Kermit

Antoine M. Kermit" Cou�tte

Last note : For many if not most of us, whether Pilots or Navigators, the angles full decimal degree presentation - favored by mathematicians and scientists (who might even prefer radians) - certainly lacks of the "immediate interpretation" which we instinctively perform when reading angles in degres, arc minutes and decimal arc minutes, ... just very simply because we got trained with this maritime and aviation universal unit distance : the Nautical Mile.

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[NavList] Re: A fluke of 0.0 intercept with Altair.
From: m_burkes---com
Date: 21 Sep 2010 12:29

Hi folks, Via HO 229 LOP straight thru DR. The real bugaboo was what appeared to me that angles were decimal until I went back to my notes of Paul's Venus obs.
Mike Burkes
m_burkes---com
626-833-1521

Date: Tue, 21 Sep 2010 11:06:21 -0700
From: pmh099---com
Subject: [NavList] Re: A fluke of 0.0 intercept with Altair.
To: NavList@fer3.com

I am getting the same results (see attached screenshots).

Peter Hakel

From: Antoine Couette <antoine.m.couette---fr>
To: NavList---org
Sent: Tue, September 21, 2010 5:13:27 AM
Subject: [NavList] Re: A fluke of 0.0 intercept with Altair.

Dear Paul,
Congratulations !
With your data, I am also computing a 0.0 NM intercept for a true azimut of 27.1 �.
Best Regards

Kermit

Note : 1 - Most generally, ALL the On Line CelNav Software available on the Internet will perform very accurate Apparent positions for the Stars (certainly well under 0'1), which is again verified with the "Navigation" Software you are using. Accurate Star apparent ccordinates are fairly straightforward and easy to compute with an accuracy of 1" for example.
2 - Have you tried the On Line Celnav Software such as US Naval Observatory ?
It is here : http://www.usno.navy.mil/USNO/astronomical-applications/data-services/cel-nav-data .
Obviously, all Governement Agencies (USNO, and others) compute very accurate CelNav Bodies apparent positions for any time / date in the full range of their validity dates.

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Ref : [NavList 13936] A fluke of 0.0 intercept with Altair.
From: pw.jackson---co.nz
Date: 21 Sep 2010 04:02

Can some one cross check my shot of Altair.
Basic Data:Known position= 36.485 south
174.481 east
Height of eye 6'4"
GMT: 21/09/2010 06:49:36
Hs: 40.262
No index error or watch error.
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