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213 Cards in this Set
 Front
 Back
geocentric view

orienting yourself with respect to the external environment


cardinal directiosn

N S E W


meridian

north south lines


cartographic map

graphic representation of the environment


5 characteristics of a map

vertical or oblique views of the env
created at a reduced scale map projectionchange spherical to fit flat generalized representations symbolized representations 

topographic map

shows elevations and landforms


orthophotomap

topographic with photo superimposed


aerial photograph

not a map projection surface,only a photo showing scale and elevation differences


reference map

maps that serve as a reference library of geographic informatoin


thematic maps

tell an essay about a particular subject in the geospatial context


propaganda maps

persuasive maps that distort information


map use

the process of obtaining useful infomration from one or more maps to help you understand the environment and improve your mental map


3 main activities of map use

read
analyze interpret 

parallels

e to w lines


lat and long are measured by

the angular distance of a parallel from the equator and a meridian from the prime meridian


Tropic of cancer and capricorn

cancer (north hemisphere)
capricorn (southern hemisphere) where the sun is directly overhead on the summer and winter solstices 

graticule

arrangement of parallels and meridians


numerical range for latitutde

0 to 90


numerical range for longitude

0 to 180


babylonian sexagesimal system

uses degree, minutes, and seconds to pinpoint location
60 minutes a degree 60 seconds a minute 

decimal degree system

does not use NSEW
equation: dd+ mm/60 + ss/3600 dd = degrees mm = minutes ss = seconds 

Where is the prime meridian located

in greenwich, a suburb of london


equation for centrifugal force

m*v^2*d


semiminor and semimajor axis

minor  N to S axis sliced in half
major  E to W axis sliced in half 

geodetic latitude

angle made by the equator and a line perpendicular to the parallel of interest on the ellipsoid of the earth


equitorial and polar radius

equitorial  6378.137
polar  6356.75231 

geodetic longitude

angle between the line from a point on the surface to the center of the earth to the prime meridian


authalic sphere

a sphere with the same SA as the reference ellipsoid being used


statute miles vs nautical miles

statute are used on land


equation for converging meridians

69.09 miles / deg. x cosine (lat)


great circle, small circle, quadrilaterals

great larger circle on ellipsoid
small when you have overlaps with another circle quadrilaterals bound by equal lat and long 

control points

points on a map of known accuracy


monument

a fixed object established by surveyors where they know the exact location


why do we treat the earth as smooth when it is authalic or oblate

because the mountains and trenches are relatively small in comparison to the diameter of the earth


rules for sig figs for if rounding with a 5

round up for odd, for even stay the same (round down)


rules for sig fig addition

decimal in the place of the one with the least amount of sig figs


scale denominator

has a one in the numerator and the "scale denominator" in the denominator


map scale

tells you the relationship between distances on the map and their corresponding ground distances.
gives you an idea of how small the map is relative to real life 

representative fraction

ratio between the map and ground distance
shown as 1:x x = scale denominator 

why would a scale bar be extended to the left past 0?

to show smaller units


on what type of map projection will you see a variable scale bar

mercator map projection


what is the typical dividing point between large and small scale maps

1:500,000
1 inch represents 500,000 inches 

conversions that need to be known

1 foot = 12 in
1 statute mile = 5280 ft 1 statute mile = 63,360 1 km = 100,000 centimeters 

length of the equator in miles

24901.46 miles


actual scale

the scale that you measure at any point on the map; it will differ from place to place because of geometric distortion


principal scale

the scale of the globe as it is reduced to its desired size


scale factor

actual scale / principle scale


completeness

ability of a map projection to show the entire earth


continuity loss

when a sphere is broken to be represented as a flat image. At one meridian , it will be represented twice on either edge of the map


conformal

when angles on the globe are preserved on the flat map


true direction projections

projections that preserve global directions


azimuth

direction from a reference point


projection families

planar, clyindrical, and conic
*imagine a light radiating from the earth and projecting a shadow of the landforms of the earth 

three perspectives for planar projections

orthographic (light source at infinity)
stereographic (light source on the surface of the globe opposite to the pooint you are looking at) gnomonic (light at center of globe) 

tangent case projection

the projection surface will only touch the globe at one point, or along one line (this is the case for a cone)


secant case projection

the projection surface intersects the globe at a small circle of tangency


advantages to secant case

there is less distortion


what are tangent projections used for

equidistant projections usually


aspect

location of the point or lines of tangency on the projection surface


equitorial aspect

when the projection line is on the equator


transverse aspect

used with cylindrical projections to refer to when the line of tangency is shifted 90 degrees to follow a pair of meridians
*tube turned horizontal instead of vertical 

oblique aspect

an aspect that is not polar, equitorial, or transverse


orthographic projection

shows the earth as how it looks from a distant planet


stereographic projection

light source from the antipodal point of the globe
usually used for polar views 

what is a gnomic projection used for

navigation for great circle routes
seismic and radio waves 

Mercator map is projected how

cylindrical conformal projection


benefit of a mercator map

that it is good for compass bearings


what is the difference between a map and a cartographic map

a map is a spatial representation of an environment, while a cartographic map is a graphic representation of an envrionment


what makes maps popular

convienient to use
simplify our surroundings credible strong visual impact 

3 different types of maps

reference, thematic, and navigation


Ex of reference maps

topographic map of Oregon, globe, road map


Ex of thematic maps

ones that will show a piece of information, such as demographic information, spread out over spatial map


Ex of navigation map

topographic maps, nautical charts, and aeronautical maps


three ways to represent scale

representative fraction
verbal scale (a sentence) scale bar 

what is the difference between geocentric and geodetic coordinates

geocentric is using a sphere
geodetic is using an oblate ellipsiod 

grid coordinate system

planerectangular system where the earth is projected to fit a flat surface and regularly space lat and long are used


cartesian coordinate system

uses x and y axis and quadrants for mapping


What does UTM stand for

universal transverse Mercator system


UTM extends through what latitude

84 N to 80 S


How many zones are in UTM and how much longitude is in each one?

sixty NS zones with 6 degrees long


what is an easting?

the EW x coordinate in a grid coord system


what is a northing?

the NS y coordinate


false easting values

easting = 500,000 m


how do you report in UTM

easting, northing, zone, hemisphere


What does UPS stand for

universal polar stereographic system


UPS system

does complete global coverage with the rectangle system as well.
has N and S zone is imposed on secant polar stereographic projection 

UPS grid center

2,000,000 mE 2,000,000 mN
no negative numbers 

state plane coordinate (SPC) system

creates grids and zones to make selling parcels of land easier


SPC zone system

follow state and county lines
each zone has its own central meridian uses ft instead of m 

what is the difference between geocentric and geodetic coordinates

geocentric is using a sphere
geodetic is using an oblate ellipsiod 

grid coordinate system

planerectangular system where the earth is projected to fit a flat surface and regularly space lat and long are used


cartesian coordinate system

uses x and y axis and quadrants for mapping


What does UTM stand for

universal transverse Mercator system


UTM extends through what latitude

84 N to 80 S


gnomonic projection

shows all great circle lines, the shortest location between two points is what is depicted on the map


azimuth

angular measurement on a spherical coordinate system


rhumb lines

lines of a constant compass heading


straight lines on a mercator projection represent

rhumb lines


straight lines on a gnomonic projection represent

great circles


loxodromic curve

the curve from following a rhumb line on a standard globe, spirallike


what way do you measure great circl azimuths

intersections with meridians, going clockwise


mercator projections have constant

compass bearings


quadrilaterals

areas bound by the same lat and long increment


aspect ratio of quardrilateral with increasing latitude

aspect changes to cosine (latitude)


SPC coordinates increase which way?

moving east and north


two ways of thinking of distance

physical distance a measured amount in standard unit of distance
or functional distance  distance measured at expenditure or cost, time, and energy 

geographic mile

represents a fraction of a degree of the earths circumference
6087.1 ft 

knot

velocity of one nautical mile and hour


a meter is defined relative to what

the speed of light


two major ways for finding distance on large scale maps

measure distance and compare it to a scale bar
use the representative fraction to convert the map distance to ground distance 

how do the length of lines for distance measuring affect error

the shorter the line, the more accurate the distance measured


external errors

result from the methods you use, judgements you make, calculations, etc


internal errors

results from the nature of the map itself. such as trying to fit a 3D world onto a 2D projection


slope error

the fact that most measurements are made on a flat surface when the earth is not like that in reality
the greater the slope, the greater the slop error 

smoothing error

maps may be smoothed by mapmakers to make lines straighter and remove irregularities


scale variation

no map projection maintains a constant correct scale throughout can lead to error


disproportionate symbol error

the size of a symbol is not proportional to its ground size (usually it is depicted larger in the proportion)


displacement

when features are spaced so that they don't visually run into each other, but, in fact, because of the disproportionate symbol effect, moving the objects for space distorts them from reality


dimensional instability

when the medium that the map is printed on changes
ex: paper can change its shape and size depending on if it is hot or cold 

distance segments

premeasured ground distance that is place between road intersections to give real distance


distance insets

double ended arrows with names of features and the distances between them


mileage map

routes between highlighted locations are shown as straight lines and labled with the accurate distancedist


distance tables

tables that identify the premeasured ground distance between a select set of locations


route segments

put on maps to make up for functional time, and they give the travel time between distances


traveltime maps

show with straight lines and how much time it takes to get between locations


isochrones

lines of equal travel distance time


thinking geocentrically

thinking in terms of geographical direction


true north

a geographical fixed location, the north pole of the axis of the earth's rotation


true north reference line

any meridian that originates from the true north


Where is the north star

on the handle of the little dipper


grid north

the northerly or zero direction indicated on the datum of the map
it does not refer to a geographical place, it is artificial 

grid declination

the angular difference between true north and grid north


magnetic north

the direction that your compass needle points to at the earth's magnetic pole


magnetic declination

the angular difference between true and magnetic north


isogonic lines

lines of constant angular distance between true and magnetic north


agonic line

where magnetic north and true north line up


Compass direction systems

compass points
azimuths bearings 

compass points

points indicated by arrows on the graphical face of a compass


azimuth

horizontal angle measured in degrees clockwise from a north reference line to a direction line


bearings

measured in degrees but only 0 to 90
measured either clockwise or cclockwise give reference line (NS) and orientation (EW) 

divisions in land partitioning

parcel
tract lot 

plat

maps drawn to scale to show lots in which the area has been subdivided


metes and bounds

a way of partitioning land based upon geographic features such as rivers, etc


seigneuries

parcels of land given to the elite and soliders in the french feudal system


french long lots

strips of land claimed along river banks. the strips were created by the owners of seigneuries, who then let everday people settle on them


land grants

parcels of land given to an owner before the land was given to the US


pueblo grants

issued to native american communities primaryily indian reservations in new mexico


private grants

property by the governments that could be sold by the owner and were made to individuals as a rewards for service to the government


community grants

land parcels that were given to groups of settlers


donation land claim

a 160 acre pacel that was given to settlers if they were on public land betfore the 1851 OR Wa ID treaty


centuriation system

a system of land partitioning first developed in roman times where land was divided into a grid and given away in parcels


what is the foundation of the US Public Land Survey System

the centuriation system of using grids


initial points and PLSS

the initial point to determine the parallel and meridian to base partitioning off of
the parallel is called the geographer's lie the meridian is called the principal meridian 

range lines

6 mile interval ew marks from the initial point


township lines

6 mile intervals ns marks


township

area bounds by 6 mi range and township lines


rows and columns on PLSS system

rows townships
columns ranges 

indicating location in PLSS system

T#(NorS), R#(EorW)


sections

townships divided into parcels of 640. a seciton is one unit


correction lines

established every 4th township to correct because meridians converge towards the north pole


government lot

designed when a parcel hits a body of water


platted lots

parcels in a platted subdivision within a section


dominion land survey

public land survey system to divide canada's prairie land and western provinces


what is different about the dominion land survey in comparision to plss

the numbering order in a section is different
range lines ID with roman numerals township lines only numbered 

land records

public records of who owns land


Slope error increases with

increasing map distance and increasing slope


orient

to align a map with the directions on the ground


inspection method

a technique of orienting maps where you do not need to know where north is
orient according to the objects that are around you, such a as road 

compass method

orienting by finding magnetic north
align the compass needle on the map and on the magnetic north of the actual compass 

the difference between true north and magnetic north

20 degrees


distance estimation by the inspection method

find specific features on the ground, locate them on the map. estimate your ground distance and then find your map distance


why can it be hard to judge distance

because of the ocular vanishing point: the point on the horizon where parallel lines appear to converge


compass method of distance estimation

find the angle to your object, locate the back azimuth and draw a line on the map


resection method

using 3 objects to triangulate your position


what is crucial with the resection method

keeping you and the object in your line of sight as close to 90 degrees as possible


stadia principles

a way of measuring distance using equipment that is based on using a constant angle to determine distance between a marker and a sighting device


laser rangefinder

using infrared to measure distances up to 1,000 yds


altimeter

measures the height above a fixed level


intersection method

taking angles from multiple points towards an object and plotting those to find out your location.
opposite of resection 

trilateration method

finding a location of a distant feature using only the distances from known locations of the feature
uses a drafting compass 

navigation has how many parts

2
planning your route following your route 

Peutinger table

A Roman simplified map that was distorted to show the road network and cities along the routes


sounding

depth measurement


isobath

bathymetric contours


dead reckoning

used in nautical navigation where you determine your position based on where you are now relative to your last accurate location


what is the standard for writing coordinates/direction in nautical

course heading first then the boat speed


piloting

following your route using landmarks and water depth to aid navigation


scale on world aeronautical charts and sectional aeronautical charts and terminal charts

1:1,000,000
1:500,000 1:250,000 

absolute positions

a specific position defined by coordinates such as lat/long, utm, spc, etc


two components of gis data

feature  the spatail aspect
attribute  describes some characteristic of the feature 

space trilateration

used in GPS, where distance is measured in multiple locations based upon velocity and time of the signals to get to the location it was received


What are the components of GPS

a space segment, such as a satellite
user segment is the receiver that is tuned to the frequency of the space segment control segment is the set of ground montoring systems that keep track of the satellites and their health 

where are GPS satellites positioned

medium earth orbit


posigrade orbit

moving with the direction of the earth's orbit


selective availability

intentionally degradating the accuracy of the gps signal so that it could not be used by hostile forces


the accuracy of a gps depends upon

field conditions
location length of time arrangements of satellites in the sky 

satellites and a solar day

satellites will appear 4 min earlier than they did earlier in the day


normal triliteration

the method of determining relative position by the geometry of triangles


what is a large source of error in GPS

the clocks not being sychronized
your position can be different because the two ranges of the gps will intersect at a different time than if they were synchronized 

elevation determiniation and gps

gps are based off of the wgsd84 ellipsoid, which is a mathamatical model of the earth's surface.
the gps heights are based on ellipsoid approximations rather than real life 

three sources of gps bias

the satallites
the gps signal the receiver 

range noise

random error in gps


observation noise

white noise of other ionospheric influences


error budget

describes the contribution of each sourceof error to the overall eroor of the satellite range of measurement


ionospheric effects

what layer of the atmosphere that the satellite is in can alter the speed and direction of a signal


receiver clock effects

the clocks inside of gps receivers are not as effective as atomic clocks


ephemeris bias

error in the position of the satellite due to the earth's gravitational pull


multipath error

when the path of the gps bounces before it makes it to the receiver


agonic line

the line of zergo magnetic declination along whihc the true and magnetic north poles are aligned


if NS utm grid lines tilt to the east...

the mapped region lies east of the central meridian of the utm zone


if the magnetic north line tilts east

mapped region is west of the agonic line


to get the back of an azimuth or bearing what should one do?

go backwards 180 degrees


explain how bearings are reported

in 0 to 90 degree increments eeither W or E of North, or W or E of South
