A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: S C Sullivan
Date: 2008 Oct 21, 12:50 -0500
Thank you for submitting a request to the NGA Maritime Customer Database. The question/comment originally submitted is listed below along with a resolution.
Subject Matter: Nautical Publications
Has anyone reported an error to the printed HO 249 Volume 2; page 158, LAT 26, Declination (0 - 14), Contrary? This page appears to be a reprint of page 152, LAT 25, Declination (0 - 14), Contrary. Credit for this goes to an engineering professor at the University of Tennessee in Memphis. Steve Sullivan
Thank you for bringing this error to our attention. In reference to HO 249 Vol.2, page 158, LAT 26, Declination (0-14), Contrary: the data on page 158 was incorrectly generated by the software used to create the online version of this publication, available on the NGA Maritime Safety Web site. The data on page 158 in the spiral-bound printed hardcopy of HO 249, Vol.2, is correct. We are working to resolve this problem with the online version.
NGA Maritime Customer Database
Gary LaPook writes:
Although the page numbering is the same in my 1970 edition of H.O 249 mine does not contain the error that you identified. I checked the online version of H.O. 249 at: http://www.nga.mil/portal/site/maritime/?epi_menuItemID=8755b5dbee96c4327b2a7fbd3227a759&epi_menuID=35ad5b8aabcefa1a0fc133443927a759&epi_baseMenuID=e106a3b5e50edce1fec24fd73927a759
and found the same error on those two pages.
Last November 28th I posted the messages below and it now appears that they have corrected on the online edition the errors I had pointed out to them at that time. The contact information in that exchange might be useful in bringing this new error to their attention.
"I recently posted a link to the government web site where you can
download copies of navigational publications including H.O 249. I
quote below the email I sent to that site:
"Quite by chance I noticed an error in the on line edition of HO 249
volume 2. I then looked for similar errors and found that there is a
systematic error in both volumes two and three. For example, on page 5
of volume 2 covering latitude 0º in the first column covering
declination of 15º at LHA 89 the altitude given is 00-58'; for LHA 90
the altitude is given as 00-00'; and for LHA 91 the altitude given is
00-58' which is the same value as given for LHA 89! This is
mathematically impossible. The problem is that the altitude for LHA 91
should be negative 00-58'. The systematic error found all across the
tables up to at least latitude 39º is that all of the last positive
altitudes tabulated should all be negative altitudes! This is also
true for the values given for contrary name declinations. For example
on page 163 of volume 2 covering latitude 27º in the first column for
0º declination tabulated for LHA 91 an altitude of 00-53'; for LHA 90
an altitude of 00-00'; and again at LHA 89 an altitude of 00-53'. The
altitude for LHA 91 should be negative 00-53'.
"I compared these examples with my printed copies of these tables
printed in 1970 and these errors do not appear in the printed version
which correctly label these altitudes as negative altitudes."
Gary LaPook writes:I recieved the following email from the government website that had
published H.O 249 with errors.
Thank you for bringing this error to our attention. It seems that the
Sight Reduction Table generation code improperly formatted entries
beginning with -0, inserting 00 instead.
I am in the process of manually updating the electronic publications,
which will be posted to our Web site in the very near future.
The errant publications were originally produced and posted to our Web
site in 1999. Which mean that, in their 8+ years of service, you are
the first and only user to notice the error!
Office of Global Navigation/Technology
National Geospatial-Intelligence Agency
Steve Sullivan wrote:Thanks for looking, I just bought my copy a few months ago. I think the online version shows the error as well. We noticed it when we were doing sights off of Fort Lauderdale this past weekend.
On Mon, Oct 20, 2008 at 2:04 PM, werner <email@example.com> wrote:
Not in mine. Different contents in pages 152 and 158. I have the 1978
On 20 Okt., 15:49, scsullivan <scsulli...@gmail.com> wrote:
> Has anyone reported an error to the printed HO 249 Volume 2; page 158,
> LAT 26, Declination (0 - 14), Contrary? This page appears to be a
> reprint of page 152, LAT 25, Declination (0 - 14), Contrary. Credit
> for this goes to an engineering professor at the University of
> Tennessee in Memphis.
> Steve Sullivan
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