Module Three - Coordinate Systems, Measurements, and Route Selection Flashcards
Geo - Reference
Used to identify a specific geolocation
Coordinate System - GPS
Used to identify the location of features on earths surface
Reference Grids
Most simplistic reference grid
map divided into grids and rows
How many coordinate systems are there
6
Gazetteer
Fancy word for index
What is the simplest grid
Reference system
Lat/Long Positions - Geographic coordinate systems
Measured in degree, minutes, and seconds
Geographic coordinate system
Lat/Long Positions
Lat/Long Position has a system used to simplify it - what is that system?
The world geographic reference system
The world geographic reference system
The earth is divided into 15 degree wide quadrants, north-south starts at 90 south & east - west starts at 180
WGRS east and west zones are labeled by what
A thought Z minus O and I
WGRS north and south zones are labeled by what
A thought M and no I
How many quadrants are there in the WGRS
288
What does MK LK 385250 make up
It is a simplified code for the WGRS the letters are for degrees and the numbers equal minutes and seconds
MK LK 38.5 (minutes) 25.0 (seconds)
Read right then up stands for what
How to read the geocode based on numbers and relation to the map
Geodetic
Survey grid take into account the earth surface
Plane rectangular grid
Doesn’t take into account the earth surface, doesn’t have to because only works with a small area of the earth surface
Cartesian coordinate system
X is east/west direction
Y is north/south
4 quadrant system - stays in the system that focus on postive only
Geographic coordinate system doesn’t deal with what
NEGATIVES
Universal transverse system
Minimal distortion rate
60, 6 degree zones - starting at 180 degree long, runs eastward
Spans 80 degrees south to 84 degrees north (more landmasses in the north)
Transverse
Extending across something.
True or False, there are two version of the UTS
True
Military and civilian
How does the UTS determin cordntes
By using Northing and Eastings in METERS, from the ORIGIN point (0,0) - quad 1,
How do we make sure the UTS is positive
Make sure quadrants are positive, has to be up (north) and to the east
C UTM
False origin - 500,00 meters west of central meridian of each zone
NH - origin is the equator
SH - origin 10,000,000 meters south of the equator
UTM
Zones are arbitrary,
when zones are split between two quadrants, special arrangements are made
M UTM
Almost identical to C UTM except for designation of grid system, HANDLES the arctic
8 degree sections - rows are labeled c - x, no I or O
North Pole = y + Z
South Pole = A + B
Only the circle of the pole
Universal Polar stenographic (UPS)
UPS is employed in unison with UTM to cover the polar regions
Grids are arbitrary
False Origin is established 2,000,000 meters to the left and 2,000,000 meters down from poles
Where is the prime meridian for UPS
Top of center of south zone
Where is the 180 meridian
top of the north zone
How does the M UTM divide up the zones
Each zone has a two letter identifier is then subdivided by 100,000 meters squares which have a repeating pattern after 18 degrees long and 24 degrees lat, 9 separate grids separating
What are the two projected coordinate systems
State Planar system and UTM
What is the difference between projected and coordinate system
Projected is taking a 3d globe and placing it on a flat surface, whereas the coordinate system is used to define a location of the surface of the earth
State plane coordinate system
Rectangular coordinate system that is used for all 50 states, larger states are separated into multiple zones
each zone has a central meridian
What system do E/W states use in the SPCS
Lambert conformal (correct shape) projection
false origin 2,000,000 feet west of central Meriden
What system do N/S states use in the SPCS
Transversal Mercator projection
false origin 500,000 feet west of central Meriden - south of southern edge of the zone in both cases
Why would some systems not work for the SPCS
Due to navigation or distoration rate
What are the two types of land pardoning systems
Systematic - United States public land survey
Unsystematic - Land - ownership plane down haphazardly
Land pardoning systems
Established at the 1783 Treaty of Paris, gave control to the land east of the mississippi and created the 1785 - land origin act
What are townships
E/W lines running parelle , 6 mile by 6 mile squares
N/S lines running parrelle to the principle meridian called
Gets broken up into 36 blocks
What is a range
N/S lines running parrelle to the principal meridian
What is an Aliquot part
Equal acreage division of section described as 1/4
What is a lot
Anything that doesnt fit the description of aliquot part
French long lot
Attempt to recreate the French federal system
large long lots grained to landowners (seigneurs)
What privileges did seigneurs have
Revive tenet payments
Require them to use his mill for grinding their grain
Demanded various work services of them
New England Fragmented village
Attempt to recreate medieval villages by puritans, used only in England in the 19th century
lots oriented to the road, very natural
Texas irregular survey system
Was created to replace townships and range
runs SW NE orientation
Very Irregular
What is a metes
Boundary defined by the measurement of each stranger run, specified distance between two points
what is a bounds
A more general boundary description
what are the rules for Measurements from map
Make sure your projection is appropriate
Accuracy standards
Appropriate scale
Map is up to date
Mapping is in good condition
Distance measuring
scaling using to measure distances, can include engineering scale, dividers, or marks
Measuring area
Direct method of measuring, with two main types
Graphic area scale
Polar parameter
What is a graphic area scale
super imposed upon transparented materials
What is a polar parameter
An instrument used to measure an area in square
What is the grid square method
Method of determining area by overlaying the area of interest with a right angle grid line
USGS topographic map
Maps that come in three popular forms,
1 quarter
15 min
7.5 mins
3 north references
true north
magnetic north
grid north
What is a compass rose
36 directions, a more complicated version of the 4 cardinal directions
What is magnetic declination
Difference between true north and magnetic north
Isotonic charts
Drawn in such a way that is depicts location of equal declination - also known as isotonic line
What is a agonic line
Lines that join at zero declination
Azimuth are defined as what
Refers to direction of great circle, will cross succession meridian at constantly changing angles - DO NOT HAVE TO ADJUST HEADING,
Simpler but longer
What is the Azimuth formula
360 - whatever angle = Azimuth
What is a back Azimuth
Opposite direction of Azimuth, add or subtract 180 from angle
What is a Bering
Directional line, often used in surveying,
NO MATTER THE LINE CANT GO PAST 90 DEGREES
What is a back Bering
Opposite direction of a Bering - just flip directional indicators
Ex: North 45 west – South 45 east
GPS
Was developed 1973 but was fully operational in 1995 - DOD was the one with the large enough budget to create this project
between 24 - 32 satalights circling the earth
How many satlights do you need for your gps to work
At least 4 at any giving time
What are the three modes of GPS
Non-differential - inexpensive for recreational navigation
Differential GPS - GPS with more accurate and uses a special software
Real time DGPS - Most expensive use to obtain GPS coordinate constant getting updates to help stay on location
