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When new
map files are acquired by the FNSB mapping division, the map files need
to conform
to certain standards so that they may be integrated with a minimum of
labor
into the online map set. Certain layer naming conventions are used
throughout
the map system. The map data is placed on a well understood common
geographic
grid so that all the maps and layers of data will fit together for the
purpose
of automation. The file format is determined by the standard use of
AutoCAD
software from Autodesk, Inc. The rest of the document specifies some of
the
important standards in more detail.
LAYER NAMES:
Each map
file will contain its data in or on one or more layers. There are three
types
of layers beginning with a letter C, G, or T. The letter C is used for
temporary construction guides, G is used for line graphics, and T is
used for
annotative text.
| LAYER |
|
TYPE |
DESCRIPTION |
|
C-ALIGN |
|
DASHED LINE |
TEMPORARY ALIGNMENT FEATURES |
|
C-CONSTR |
|
SOLID LINE |
TEMPORARY CONSTRUCTION
FEATURES |
|
C-GPS-SEC |
|
POINT |
GPS POSITION OF SECTION
CORNER |
|
C-GRID |
 |
POINT |
PLSS PROTRACTED GRID |
|
C-POINT |
 |
POINT |
TEMPORARY CONSTRUCTION
FEATURE |
|
C-SEC-CORNER |
 |
POINT |
ESTIMATED POSITION OF
SECTION CORNER |
|
C-TIE |
 |
DASHED LINE |
TIE LINE FOR ALIGNING
FEATURES |
|
G-EZMNT |
 |
DASHED LINE |
EASEMENTS |
|
G-FLOODCONTROL |
 |
SOLID LINE |
FLOOD CONTROL FEATURES AND
EASEMENTS |
|
G-HOOK |
 |
SOLID LINE |
PARCEL LAND HOOK |
|
G-LEASE |
 |
DASH-DOT LINE |
LEASE LOT |
|
G-LOT |
 |
SOLID LINE |
LOT / PARCEL BOUNDARY LINE |
|
G-LOT-GOV |
|
DOTTED LINE |
GOVERNMENT LOT |
|
G-LOT-OLD |
 |
DASHED LINE |
OLD LOT BOUNDARY LINES |
|
G-MONUMENT |
|
POINT |
VARIOUS MONUMENTS |
|
G-PLANI |
 |
DASHED LINE |
PLANIMETRIC DETAILS |
|
G-RIVER |
 |
SOLID LINE |
RIVER & CREEK MEANDER LINES |
|
G-RIVER-OLD |
 |
DASHED LINE |
OLD RIVER & CREEK MEANDER
LINES |
G-ROAD
|
|
SOLID LINE |
PLATTED ROAD RIGHT OF WAY |
|
G-ROAD-BREAK |
 |
DASH-DOT LINE |
ROAD BREAK LINES FOR
CONVERSION TO GIS |
|
G-ROAD-PRIVATE |
 |
DASHED LINE |
PRIVATE ROADS |
|
G-SCLIN |
 |
DASHED LINE |
SECTION LINES |
|
G-TRAIL |
 |
DASHED LINE |
TRAIL CENTERLINE |
|
G-WATER |
|
SOLID LINE |
LAKES & SMALL WATER BODIES |
|
T-AREA |
 |
TEXT |
AREA IN SQUARE FEET AND/OR
ACRES |
|
T-BLOCK |
 |
TEXT |
BLOCK NUMBER |
|
T-DIM |
 |
TEXT |
DIMENSIONS OF LOT LINES |
|
T-FILENAME |
 |
TEXT |
RECORDED PLAT NUMBERS,
BOOK-PAGE, & OTHER FILE NUMBERS |
|
T-LOT |
|
TEXT |
LOT NUMBER |
|
T-LOT-GOV |
|
TEXT |
GOVERNMENT LOT NUMBERS |
|
T-MEMO |
|
TEXT |
MEMO LAYER - BORDER AND
LEGEND |
|
T-NOTES |
 |
TEXT |
VARIOUS NOTES |
|
T-RIVER |
|
TEXT |
RIVER AND CREEK NAMES |
|
T-SCLIN |
|
TEXT |
SECTION CORNER NUMBERS |
|
T-SUB |
|
TEXT |
SUBDIVISION NAMES |
|
T-SURV-CORNER |
 |
TEXT |
SURVEY CORNER NUMBERS |
|
T-WATER |
|
TEXT |
LAKE & SMALL WATER BODY
NAMES |
THE MAP FILE NAMING SYSTEM:
There
are two kinds of files, both geographically
based.
Area-wide
files are grouped by the type of data
they contain. While everything is on coordinates and may overlay the
base map
easily, these files each cover many base maps. Some contain all of a
particular
type of information for the entire borough in one file.
The base
maps are divided up along township,
section and quarter section lines in a similar manner as the old mylar
maps.
The base
map file naming system is geographically
based, with the map file name representing the location of the
particular piece
of ground. The file naming system uses six characters.
1. The
first character represents the quadrant of the Fairbanks Meridian:
- "1"
represents the townships to the northeast of the Birch Hill Initial
Point.
- "2"
represents the southeast.
- "3"
represents the southwest.
- "4"
represents the northwest.
- Two
more regions, known as "5" and "6", cover the eastern, less populated,
area of the Borough.
2. The
second character represents the Township number, north or south.
3. The
third character represents the Range number, east or west.
4. The
fourth character is a letter from "A" to "I" representing a square
group of four sections within the township.
5
& 6. The fifth and sixth characters are used only for maps of
quarter-sections.
See the key map for
further clarification of the map numbering and file naming system.
THE GRID:
The
Borough map files are each placed on a
continuous state plane grid consisting entirely of Alaska Zone 3,
NAD83.
Township corners within the Borough boundary have been located by the
BLM
protracted coordinates. Actual field section corners set by rectangular
survey
may vary from this mathematical grid. Any file received in these
coordinates can
be immediately inserted into the map system.
MAP ACCURACY:
Although
it would be well to have all data within
ten feet of true location, just as if everything were tied by survey to
primary
monuments, in most cases the information will not be so well known. New
subdivisions are being entered directly from the recorded plats using
tie points
and basis of bearing as noted on the plats, digitized data from printed
maps
such as the U.S.G.S. 15-minute and 7½ minute quad sheets will have an
inherent
accuracy commensurate inversely with the source scale, and the old
hand-drawn
Borough base maps were precise enough for sparse land development and
have that
level of accuracy.
Currentness
is more important than geographical
precision and accuracy.
FILE FORMATS:
Map data
files are in a format that can be read
directly by AutoCAD (Release 2000 or later).
Such formats include the standard AutoCAD .DWG, .DXF, or possibly
.DWF. AutoCAD LT can
also be
used to read and work with AutoCAD drawings.
These
files are maintained by the Department of
Community Planning, Mapping Division. Questions on setting up your own
system
map files may be directed to Bernardo Hernandez, Director of Community Planning.
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