A
geocell is herewith defined
as an area bounded by one degree of latitude and longitude. The earth-orb
has 64,800 geocells. Most are quadrilaterals, but the 360 surrounding each
pole are trilateral. Their length is constant; their width varies. A geocell
is nearly square at the equator; narrows to a spike at the poles.
Globes and maps usually show geocells—but in combinations
that vary widely from item to item: e.g., 15 x 15º, 2 x 4º, etc.
Till now, so elementary a terrestrial unit as 1º x 1º has gone
unnamed. And the lumping of geocells in any map has been a haphazard detail.
A meticulous one-degree world map or globe would depict
all parallels and meridians, and all 64,800 geocells (except perhaps for
1º x 5º geocells within five degrees from the poles). I have never
seen or heard of an entire world map or globe drawn to one degree. The Megamap
described below would be the first to incorporate all geocells.
Most commercial globes, typically twelve inches, show
15º intervals. A few European products have 10º. Even big showpiece
globes lack a full set of geocells. FDR's 50-inch globe, now in the Library
of Congress, only has 5º geocells. The National Geographic Society's
11-footer in its Washington headquarters, is but a blow-up of its
15º twelve-inch model.
Likewise for complete world maps: generally 15º,
sometimes 10º, seldom 5º; and 1º—why bother?
There is an obvious reason why a one-degree world map
or globe may heretofore have seemed impractical: the traditional division
of labor between notoriously distorted world maps (or unwieldy globes), and
highly precise localized charts. If you want a rough—a very rough—idea of
what's where on earth, you check a world map. If you want a more exact idea
about the ebb and flow of Mideast boundaries, then you examine a sectional
sheet or atlas, likelier to be at the one-degree level.
There is also a subconscious reason, so to speak, for
the nonexistence of one-degree world maps and globes. A one-degree resolution
in most world maps would more vividly expose their un-realism, their gross
exaggerations: their abuse of geocells transformed beyond any compatibility
with a globe:
if there was a one-degree globe to compare them with!
Even without a one-degree globe, the deformations would
be conspicuous. For, despite their variable width, all geocells are of the
same length, mesh, and alignment. Bloat, stretch, and contortion would betray
themselves all the more visibly if commonplace world maps were drawn to 1º.
Many, many cancerous geocells would be conspicuous next to their more accurate
neighbors.
Furthermore, imagine an ordinary world map enlarged
to 1/1,000,000—say, to an equatorial length of about 40 m (132'). Imperfections,
and geocell distortion, which go unnoticed—and undepicted—in book size and
wall size world maps would become intolerably grotesque if seen at the larger
scale. Ergo, it just isn't done. Not at 1/10,000,000, much less 1/1,000,000.
At these scales or larger, you must go to a provincial atlas, or separate
national sheet-map series, or the non-integral sheets of the 1/1,000,000
International Map of the World (IMW).
The conclusion we draw thus far is this: the word "geocell"
did not exist in either geometry or cartography, and its lack was symptomatic
of the inattention to that degree of resolution in world maps (as well as
globes).
In the lengthy course of designing and drawing the
one-degree Megamap 1/1,000,000, I determined that a prime desideratum must
be
overall proportionality of the geocells—proportionality to the
adjoining ones
and to the network as a whole,
and to a corresponding
globe with all 64,800 geocells.
I say
proportionality. Of course, by nature,
geocells on a sphere and a flat map cannot be identical. In the Cahill-Keyes
"Real-World" Map, the equator and two meridianal great circles (20 &
110 W, etc.) match the scale of a hypothetical counterpart globe. All other
meridians and parallels are progressively and proportionately shorter toward
the center of the octant. I.e., all of the geocells have a specified amount
of shrinkage vis-a-vis their global parent—but none of them is out of keeping
with any other geocell on the globe, nor in adjacent ranks and files, nor
anywhere in the entire map.
I make that statement as an artistic fact, not a geodetic
one. The map is
not accurate enough, thank goodness, for artillery
fire or missile trajectories. But the map design, and my computation tables
to four decimal places for all 64,800 geocells—their length, their width,
and their x,y coordinates—
are accurate enough to enable work to proceed
on creating this largest of all world maps, this progenitor of the Coherent
World Map System, this Megamap in a single frame, 20 x 40 m (66 x 132').
Indeed, the tables could be used for a 1,100,000 version
ten times longer, if there was a site for it; or a 1/10,000 ground plan for
a "Fair World World Fair" or theme park 2 x 4 km. Except for the 1º
x 5º geocells around the poles, the Megamap would contain in eye-pleasing
array every single geocell on planet earth,
and every single continent
in uninterrupted entirety and in reasonable fidelity to those same profiles
as seen on a globe.
But that too is an artistic as well as a scientific
judgment. To flatten a sphere, we must either stretch or shrink its surface
differentially. The trade-off in the Megamap is its compression. Nonetheless,
I aver that the Cahill-Keyes "Real-World" Map bears a better isomorphism
to a globe than any other integral world map. And I invite skeptics to account
for the size and disposition of every geocell in their alternative.
All the continents share the shrinkage—some vertically
and more horizontally—but not to an inordinate degree. Instead, every 1º
geocell is in good shape, present and accounted for, in well-tempered collocation,
none grossly at odds with any other geocell in the big picture.
To summarize: the design for a single world map of
unprecedented size has required a singular re-focus on an unappreciated
(and previously undesignated) basic unit of mapping, whether plane or planet:
namely. the
geocell, one degree of latitude and longitude. It is
the fine-tuned proportionality of a total geocell assemblage which enables
the Megamap to serve
both as a giant exhibition conspectus of the
whole earth,
and as the selfsame source of any partial or complete
map at smaller or larger scales.
Update postscript (1), 1983-05-23:
Since writing the above draft, I have received from
Buckminster Fuller's World Game office in Philadelphia a 1/21,000,000 "Grip-Kitrick
Edition" of the icosahedral Sky-ocean map, published in 1980. It is an exception
which proves the rule: this world map has a half-degree graticule! Apparently
computer-drafted, it has a stupendously detailed set of coastlines, rivers,
and lakes; and no political borders.
By way of observation, rather than nit-picking, I make
these comments regarding its portrayal of the graticule:
1) I presume it is computer-drawn, given the way the
meridians and parallels quaver.
2) Half-degree resolution is too much of a good thing:
it divides one geocell into four, and overburdens the eye. (We'd have
as many as 259,000 geocells, rather than 64,800.) I would not go to quarter-geocells
until a much larger scale, and then would subdivide geocells using a broken
line or the like.
3) It does not identify latitude and longitude, except
at the most far-flung intervals. I use repetitive line-by-line numbering.
4) It does not accentuate latitude and longitude by
any intervals. I use 5º accentuation.
5) Though predominantly at half-degree resolution,
geocell size varies when approaching the poles, from 1/2 x 1/2, to 1/2 x
3, to 1/2 x 15, to 1/2 by 45, to 1/2 by 90 degrees, respectively.
6) Geocell alignment is impaired all along each joint
of the 20 triangles.
7) Geocell disparities are visible through and through,
especially at the joints and vertices of the triangles, confirming one of
my major critiques of the sky-ocean icosahedral map.
Still, it is a map I wish I had done! Though I would
allocate the geocells differently, I judge it to be a superb rendition on
a problematic chassis.
Update postscript (2), 2007-03-31:
Despite some prototypes, I was unable to obtain funding
to execute a complete Megamap; and had to mothball the project for that and
other personal reasons.
Returning to the theme almost a quarter century later, now
in the Internet age, I Googled
geocell + latitude + longitude
to see if such a concept had re-appeared: and indeed, it had. While not
in any dictionary yet—and excluding non-cartographic variants such as for
cell-phones—five technical online publications define the term as I had in
1983. All are military:
1) 1998-02-01
Jumper, John P., Lt Gen, USAF,
USAF INTELLIGENCE TARGETING GUIDE: AIR
FORCE PAMPHLET 14- 210 Intelligence
http://www.fas.org/irp/doddir/usaf/afpam14-210/part13.htm
http://www.e-publishing.af.mil/pubfiles/af/14/afpam14-210/afpam14-210.pdf
At the equator, a product rectangle is a 1 degree x 1 degree
geocell and is bounded by 1 degree parallels on the north and south and by
1 degree meridians on the east and west. (p. 101)
2) 2001-02
FEBRUARY 2001 TMD IPB [cited on Google but inaccessible:]
https://www.doctrine.quantico.usmc.mil/signpubs/r23c.pdf
1-degree x 1-degree geocell
3) 2004
Lewis, Nephi
, Generating Polygons in Real Time: Minimizing Synthetic
Environment Costs I/ITSEC 2004 Conference Proceedings [Interservice/Industry
Training Simulation & Education Conference]...sponsored by the National
Training Systems Association (NTSA), an affiliate of the National Defense
Industrial Association (NDIA)
http://www.google.ca/search?q=geocell+latitude+longitude&meta=
[Excerpt from Google result itself:
pdf paper requires membership]:
A geocell is defined as an area of the earth covering. one
degree in latitude and one degree in longitude.
4) 2005-09
Wells, William David,
GENERATING ENHANCED NATURAL ENVIRONMENTS AND
TERRAIN FOR INTERACTIVE COMBAT SIMULATIONS (GENETICS) Monterey,
CA: Naval Postgraduate School, dissertation
http://www.movesinstitute.org/~wdwells/GENETICS%20Dissertation.pdf
A geocell (i.e. 1 degree x 1 degree, nominally 100 km x 100
km) . . . (p. 9)
5) 2006-10 / 2004-11
CONTROLLED IMAGE BASE (CIB)
On the other hand, Google turned up two different results from the same line
item, a US Army Enginneer fact sheet about the Controlled Image Base (CIB),
"a standard National Geospatial-Intelligence Agency (NGA) digital imagery
product produced to support mission planning and Command,
Control, Communications and Intelligence (C3I) systems."
[PDF]
Controlled-Image Base (CIB) Fact SheetFile Format: PDF/Adobe Acrobat - View as HTML
The number of image frames per 1-degree x 1-degree geocell
is contingent on ... 1-meter CIB: One 24' Latitude by 36' Longitude
section per CD-ROM ... www.tec.army.mil/fact_sheet/cib.pdf
- Similar
pages
The HTML version did indeed mention "geocell" as above; that was from 2004-11:
The number of image frames per 1-degree x 1-degree geocell is contingent
on resolution and latitude.
However, the later PDF version from 2006-10 had changed the usage:
The number of frames per 1 x 1 degree cell is contingent on resolution
and latitude.