The first thing you'll notice is the big yellow blot that is
Houston. Contrary to popular belief among pilots, the yellow
does NOT signify the boundaries of the city. After all, what
good would a city boundary do for a pilot in the air? The
yellow indicates the approximate light pattern at night of
populated area from the air, which is much more useful
information. If you're flying at night, these patterns may
be the only thing you can see from, say, 8,000 feet in the
air, so looking at a recognizable pattern may be a big help
in determining where you are.

This was just a page I found on the Internet. I know that
somewhere I have a government handbook, perhaps the USAF
Navigators handbook, that gave the answer.





".Blueskies." wrote in
message
y.net...
| According to the naco link below, these are populated
areas. I know I always thought it was the outline of lights
also,
| but I cannot find that defined anywhere...
|
| Those census facts are interesting - scary for my area,
Kalamazoo, MI, but still interesting...
|
|
|
| "Jim Macklin" wrote
in message news:3Fnyg.84443$ZW3.22903@dukeread04...
| : Actually, the yellow area is a representation of the way
a
| : city looks at night, the pattern of the lights.
| :
| : see
http://quickfacts.census.gov/qfd/states/20/20071.html
| : and then browse to find useful info. For instance
Greeley
| : Co. Kansas has 2 people per square mile.
| :
| :
| :
| : ".Blueskies." wrote in
| : message
| : . com...
| : | The sectional charts show 'populated' areas in yellow.
If
| : it is not yellow, then is it 'unpopulated'?
| : |
| : |
| :
http://www.naco.faa.gov/content/naco...FR_Symbols.pdf
| : |
| : |
| : |
| : | "Peter Duniho" wrote in
| : message ...
| : | : "Jim Macklin"
| : wrote in message
| : | : news:bAeyg.84402$ZW3.76333@dukeread04...
| : | : Yes, I read your words and my opinion is that your
| : FSDO is
| : | : insane.
| : | :
| : | : Perhaps they are. I have no facts to suggest
otherwise.
| : | :
| : | : However, be that as it may, they are interpreting
the
| : FARs, and the NTSB has
| : | : found that where the FARs are vague, the FAA's
| : interpretation is the one
| : | : that is used, even if that interpretation is
contrary to
| : "common definition"
| : | : (and frankly, the actual "common definition" of
| : "sparsely" is even more
| : | : vague than any official definition...can you tell me
| : exactly how "widely
| : | : spaced" the intervals between population need to be
in
| : order to qualify as
| : | : "sparsely" under the common definition of
"Occurring,
| : growing, or settled at
| : | : widely spaced intervals"?).
| : | :
| : |
| : |
| :
| :
|
|