GIS Exam 1

You're standing on a point where you know the Ellipsoidal height to be 32 meters, and your geoidal height is 40 meters. What is your orthometric height? Include only numbers in your answer (don't enter unit abbreviations). Also, if needed, negative signs are part of a number and should be included.

-8.0

Convert the Latitude 00 01' 00" from DMS to DD (enter degrees, the decimal, and at least the 4 digits to the right of the decimal, e.g., 174.1234)

0.0166667

Positional differences due to the datum shift between NAD27 and NAD83(CORS96) are typically in what range?

10s to 100s of meters

Assume an Earth radius of 6,278 kilometers. What is the ground surface distance, expressed in meters, of an arc the spans 1 degree and 30 minutes of arc? Please enter your answer to the nearest 0.1 meter

164.3

Convert the Latitude 179 00' 30" from DMS to DD (enter the degrees, the decimal, and at least the first 4 digits to the right of the decimal)

179.00833

Two seconds of longitude span approximately 61.34 meters at the Equator. How many meters are spanned by two degrees of longitude at the Equator?

220824.0

How many bytes are required to store a raster that is 2000 rows by 3000 columns of 8-bit data?

6000000.0

How many bytes are required to store a raster that is 400 rows by 800 columns of long(16 bit) data?

640000.0

You have obtained data in an NAD27, State Plane coordinate system, and wish to include it in a project in a WGS84(G1150), UTM coordinate system. Your allowable error is 10 meters. Which of the following are the minimum operations to convert your data, and still meet your accuracy/error requirement.

Apply a projection from State plane to geographic coordinates, apply an appropriate datum transformation from NAD27 to WGS84, and then project from geographic coordinates to UTM coordinates

A datum shift for a point means the physical location of the point has shifted relative to other points

False

Geographic north is equal to grid north over most areas of the UTM projection

False

Vector data models are typically simpler than raster data models

False

Which of the following are valid latitudes or longitudes?

False = S105 59' 41" False = 336.349 False = 115 15' -45" False = 109 10' 61.225" True = w145 59' 59.99" False = N16 11' 28" True = E139 45' 7"

Check all true topological rules within and between the two polygon and one point layer below. Building footprints are orange, parcel polygons in light green, building centroids as dark blue points.

False = There must be no gaps between parcel polygons True = Parcel polygons must not overlap False = There must be only one building per parcel False = Buildings must be completely contained within an individual parcel True = Buildings must not overlap True = There must be one centroid per building True = Building centroids have to be contained within building polygons

Check next to the primary reasons different datums were used on different continents prior to the 1980s

False = There were no computers, limiting the number of points and hence area spanned. False = There was no way to calibrate instruments reliable across distance, particularly in precise timing measurements needed for accurate astronomical surveying. False = Different governments used incompatible measurement systems (e.g. feet vs. meters). True = Measurements networks could not span oceans, so different datum shifts were required for each continent. False = Governments wanted to keep surveying data as national secrets, and so didn't share datum measurements.

You must create a statewide map of Kansas. Choose the projection you would select from to minimize average distortion over a single data layer covering the entire state.

Lambert Conformal Conic

You must create a statewide map of Virginia. Choose the projection you would select from to minimize average distortion over a single data layer covering the entire state.

Lambert Conformal Conic

For the table below, indicate the rows where run-length coding results in a net space savings, assuming one byte per cell, and one byte per code and run-length, as discussed in the book and class

Row 1 Row 2 Row 3

For the table below, indicate the rows where run-length coding results in a net space savings, assuming one byte per cell, and one byte per code and run-length, as discussed in the book and class

Row 1 Row 2 Row 3 Row 4

You must create a statewide map of Indiana. Choose the projection you would select from to minimize average distortion over a single data layer that covers the entire state.

Transverse Mercator

Line thinning is often required when converting from a digital vector layer to a raster layer

True

Which of the following are allowable geographic coordinates?

True = N 45 59' 59.999" False = S95 36' 15" True = E174 15' 45" False = No answer text provided. False = W 170 15' 65.302" True = 36.349 False = 45 62' 28" True = Longitude -127 45' 7"

Check all true topological rules within and between the two polygon and one point layer below. Building footprints are orange, parcel polygons in light green, building centroids as dark blue points.

True = Parcel polygons must not overlap True = There must be no gaps between parcel polygons False = There must be only one building per parcel True = There must be one centroid per building True = Building centroids have to be contained within building polygons True = Buildings must not overlap False = Buildings must be completely contained within an individual parcel

Which of the following are valid latitudes or longitudes?

True = S00 00' 00.000" False = N145 51' 21" False = W90 60' 00.000" False = 188 22' 18.23" True = -89 34' 33.3333": False = S179 01' 22.8" True = E179 59' 58.999

Check all true topological rules within and between the two polygon and one point layer below. Building footprints are orange, parcel polygons in light green, and building centroid the dark blue dots.

True = There may be multiple buildings per parcel True = There must be no gaps between parcel polygons False = Buildings must not overlap False = Each building must be completely contained within a single parcel in the parcels layer False = Building centroids must fall within building polygons True = Parcel polygons must not overlap

Match the term on the left to the best description on the right Zenith angle Declination angle Geoid Ellipsoid Spheroid plumb bob

Zenith angle - A measurement from a local vertical angle to an object above the horizon Declination angle - The angle between geographic north and magnetic north Geoid - A primarily measured and interpolated representation of the true shape of the Earth Ellipsoid - A mathematical, idealized representation of the shape of the Earth, with different polar and equilateral radii Spheroid - A mathematical, idealized representation of the shape of the Earth, with a single radius plumb bob - A weighted line that indicates the direction of the gravitational force

Positional differences due to the datum shift between WGS84(G730) and ITRF08 are typically in what range?

from 10s of centimeters to about a meter