GISP Actual Questions and Correct Answers
Q1
Georeferencing
Answer: associating a map or image with spatial locations
Q2
Control points
Answer: consisting of multiple points, points come in pairs that match the spatial
location with a point on an unreferenced image or map
Q3
International Terrestrial Reference System (ITRS)
Answer: Three-dimensional coordinate system with a well-defined origin (the center of
mass of the Earth) and three orthogonal coordinate axes (X,Y,Z)
Q4
Map projection
Answer: transforming coordinate from a curved earth to a flat map
Q5
Horizontal datum
Answer: Model of the earth as a spheroid (2 components, reference ellipsoid and a set
of survey points both the shape of the spheroid and its position relative to the earth
Q6
Vertical datum
Answer: reference points for elevations of surfaces and features on the Earth - could
be based on tidal, sea levels, gravimetric, based on a geoid
Q7
NAVD88
Answer: gravity based geodetic datum in North America
,Q8
Geodetic datum
Answer: set of control points whose geometric relationships are known, either through
measurements or calculation
Q9
WGS 84
Answer: World Geodetic System - reference coordinate system used by the Global
Positioning System (GPS)
Q10
SRID integer
Answer: spatial reference system id numbers, including EPSG codes defined by the
international Association of Oil and Gas Producers
Q11
4 distortions
Answer: Distance, Direction, Shape, and Area
Q12
Mercator Projection
Answer: Preserves shape and direction, area gets distorted - projecting earth onto a
cylinder tangent to a meridian
Q13
Azimuthal Equidistant
Answer: planar (tangent) - used for air route distances - distances measured from the
center are true - distortion of other properties increases away from the center point
Q14
Cylindrical equal-area projections
Answer: preserves area, shape and distance gets distorted near the upper and lower
regions of the map - straight meridians and parallels - meridians are equally spaced
and the parallels are unequally spaced
, Q15
Conic projections
Answer: preserves directions and areas in limited areas - distorts distances and scale
except along standard parallels - generated by projecting a spherical surface onto a
cone
Q16
Choosing a projections
Answer: Latitude - low-latitude areas (near equator) use a conical projections, Polar
regions use an Azimuthal planar projection
Q17
Discrete features
Answer: a feature that has a definable boundary, begins, and ends, for example a
highway or lake.
Q18
Continuous feature
Answer: each location is a measure of something, for example temperature
Q19
Geoid
Answer: represents the true physical shape of the Earth
Q20
Reference ellipsoid
Answer: a smoothed mathematically defined surface that approximates the geoid
Q21
Oblate ellipsoid
Answer: resembles a sphere, but is slightly flattened at the poles.
Q1
Georeferencing
Answer: associating a map or image with spatial locations
Q2
Control points
Answer: consisting of multiple points, points come in pairs that match the spatial
location with a point on an unreferenced image or map
Q3
International Terrestrial Reference System (ITRS)
Answer: Three-dimensional coordinate system with a well-defined origin (the center of
mass of the Earth) and three orthogonal coordinate axes (X,Y,Z)
Q4
Map projection
Answer: transforming coordinate from a curved earth to a flat map
Q5
Horizontal datum
Answer: Model of the earth as a spheroid (2 components, reference ellipsoid and a set
of survey points both the shape of the spheroid and its position relative to the earth
Q6
Vertical datum
Answer: reference points for elevations of surfaces and features on the Earth - could
be based on tidal, sea levels, gravimetric, based on a geoid
Q7
NAVD88
Answer: gravity based geodetic datum in North America
,Q8
Geodetic datum
Answer: set of control points whose geometric relationships are known, either through
measurements or calculation
Q9
WGS 84
Answer: World Geodetic System - reference coordinate system used by the Global
Positioning System (GPS)
Q10
SRID integer
Answer: spatial reference system id numbers, including EPSG codes defined by the
international Association of Oil and Gas Producers
Q11
4 distortions
Answer: Distance, Direction, Shape, and Area
Q12
Mercator Projection
Answer: Preserves shape and direction, area gets distorted - projecting earth onto a
cylinder tangent to a meridian
Q13
Azimuthal Equidistant
Answer: planar (tangent) - used for air route distances - distances measured from the
center are true - distortion of other properties increases away from the center point
Q14
Cylindrical equal-area projections
Answer: preserves area, shape and distance gets distorted near the upper and lower
regions of the map - straight meridians and parallels - meridians are equally spaced
and the parallels are unequally spaced
, Q15
Conic projections
Answer: preserves directions and areas in limited areas - distorts distances and scale
except along standard parallels - generated by projecting a spherical surface onto a
cone
Q16
Choosing a projections
Answer: Latitude - low-latitude areas (near equator) use a conical projections, Polar
regions use an Azimuthal planar projection
Q17
Discrete features
Answer: a feature that has a definable boundary, begins, and ends, for example a
highway or lake.
Q18
Continuous feature
Answer: each location is a measure of something, for example temperature
Q19
Geoid
Answer: represents the true physical shape of the Earth
Q20
Reference ellipsoid
Answer: a smoothed mathematically defined surface that approximates the geoid
Q21
Oblate ellipsoid
Answer: resembles a sphere, but is slightly flattened at the poles.
