-------- Original Message --------
Subject: legends for NIMA/NGA charts
Date: Mon, 22 Dec 2008 17:32:25 -0600
From: Lee, Kent (EVC) <[log in to unmask]>
To: <[log in to unmask]>
Kathy/Michael/List:
I asked our production team to look into this matter since we have a lot
of experience with NGA-standard products, including producing them. Here
is what our main engineer says:
(1) The remarks from Kathy below are generally very true. TPCs and other
NGA/NIMA/DMA mapping products are indeed inconsistent throughout a
global series of maps of the same scale/category. We have run into this
issue on multiple occasions creating compressed raster mosaics of
multiple ONC/TPC/JOG sheets for our clients. That matter has raised
several concerns from our clients in regards to the consistency of
symbology rules that was used to compile such maps. Please refer to the
sample below (L-03-* TPCs are shown):
(2) There could be multiple areas on a typical TPC map where elevation /
vegetation / other info is incomplete and therefore is not shown. Such
areas would intentionally be left blank.
(3) Elevation tints colors (or lack thereof) are probably the single
most definitive reason for adjacent maps to look different. In a digital
environment the scanning parameters / quality standards would also
typically contribute to further widening color discrepancies between
adjacent maps.
(4) All the “charts” (GNC/JNC/ONC/TPC/JOG) were compiled by DMA/NIMA/NGA
based on the respective military standards (MIL-O-######, MIL-T-#####,
MIL-J-#####, etc.), most of which are easily found via googling or
browsing the NGA website (www.nga.mil). (JNC charts are also produced by
the respective Australian authorities; ONC and TPC charts are also
produced by the respective UK, Canadian, and Australian authorities; and
JOGs are produced by numerous NATO and other allied countries—presumably
they all should follow the same DMA/NIMA/NGA production and symbology
standards.) For instance TPC standards are based on mil-t-89101 tpc.pdf
<file:///%5C%5Cnas%5Cevcshare%5CCARTO.DEP%5CMaps%5CGEODATA%5CTechnical_Manuals_and_Procedures%5CNGA%5CTPC%5Cmil-t-89101%20tpc.pdf>.
Every standard specifies its own set rules to determine how a certain
feature should be displayed based on combination of its FACS code and
attribute values. The symbology standard that is also referred to in any
of those product standards is MIL-STD-2402 (STANDARD PRACTICE FOR
MAPPING, CHARTING & GEODESY SYMBOLS FOR GRAPHIC PRODUCTS):
Mil-std-2402_symbols.pdf
<file:///%5C%5Cnas%5Cevcshare%5CCARTO.DEP%5CMaps%5CGEODATA%5CTechnical_Manuals_and_Procedures%5CNGA%5CMAPPING%5Cmil-std-2402_symbols.pdf>.
(Unfortunately the actual color symbols themselves are all contained in
an “Appendix A”, pp. 611-728 which must be requested from NGA via a
15-year old fax number which no longer works. If we can get it we’ll
make a posting later to Maps-L.) A more visual approach with symbols
optimized for digital display can be found in
Mil-prf-89045_2003_geosym.pdf
<file:///%5C%5Cnas%5Cevcshare%5CCARTO.DEP%5CMaps%5CGEODATA%5CTechnical_Manuals_and_Procedures%5CNGA%5CMAPPING%5Cmil-prf-89045_2003_geosym.pdf>
(5) Generally the symbology guidelines should be taken from the
respective legend for each particular chart.
Sorry it’s not simpler.
Best,
Kent
Kent D. Lee
President and CEO
East View Cartographic, Inc.
10601 Wayzata Blvd.
Minneapolis, MN USA 55305
Phone: +1.952.252.1201
Fax: +1.952.252.1202
[log in to unmask] <mailto:[log in to unmask]>
www.cartographic.com <http://www.cartographic.com>
-----Original Message-----
From: Maps, Air Photo & Geospatial Systems Forum
[mailto:[log in to unmask]] On Behalf Of Maps-L Moderator
Sent: Thursday, December 18, 2008 8:27 AM
To: [log in to unmask]
Subject: Re: legends for NIMA/NGA charts
-------- Original Message --------
Subject: Re: legends for NIMA/NGA charts
Date: Tue, 16 Dec 2008 14:26:48 -0800 (PST)
From: Kathy Stroud <[log in to unmask]>
To: [log in to unmask]
Mike,
I had this question a few years ago and ended up contacting NGA. The
first person I corresponded with referred me to the FAA charts, but when
I asked if I could assume that they used the same symbols, I was told
no. After a few phone calls, I eventually spoke with a live person.
Based on my conversations with them, it's my understanding that the
symbols for terrain features on the TPCs have not been standardized.
They may vary from area to area because the NGA uses topographic maps
from different sources (e.g., a foreign government's mapping agency) as
the base maps for it's TPCs. The symbols are carried over from those
base maps. The symbols that are standardized by NGA are the ones shown
on the legend.
If you find a different answer, please let the list know.
Thanks,
Kathy Stroud, Map/GIS Librarian
Biological/Agricultural Sciences, Shields Library
100 NW Quad Ave.
Davis, CA 95616-5292
530-752-5248
----- "Maps-L Moderator" <[log in to unmask]> wrote:
> -------- Original Message --------
> Subject: legends for NIMA/NGA charts
> Date: Tue, 16 Dec 2008 14:32:41 -0500
> From: Michael Fry <[log in to unmask]>
> Organization: University of Maryland Libraries
> To: Maps and Air Photo Systems Forum <[log in to unmask]>
>
>
>
> Anybody know if there's a legend or guide to symbols used on NGA's
> aero charts (i.e., TPCs)? [James
> Boxall asked this question in '96 but I didn't find any replies in the
> listserv archives. You
> remember the answer, James?! ;)]
>
> FAA's Aeronautical Chart User's Guide
> [http://www.naco.faa.gov/index.asp?xml=naco/online/aero_guide]
> describes chart symbols used in FAA's domestic aero charts, but
> according to the National
> Aeronautical Charting Office rep I just spoke to, the Guide applies
> *only* to domestic aero charts,
> not to DoD's int'l charts. I've not found evidence of an equivalent
> guide for DoD charts, either in
> my collection or online, so I'm hesitant to tell my patron that FAA's
> could be safely used (even
> though I suspect it could).
>
> Thanks for any ideas.
> mf
> --
> Michael Fry
> Government Information, Maps and GIS Services
> 4118 McKeldin Library
> University of Maryland
> College Park, MD 20742
> 301.314.1357 | [log in to unmask]
|
