GISP Exam Questions with Verified Correct
Answers
Georeferencing
101- associating a map or image with spatial location
control points
101- points come in pairs that match the spatial location with a point on an unreferenced
image or map
Spatial Reference Systems (SRS)
101- coordinate based local, regional, or global system used to location geographical entities
(aka Coordinate Reference System (CRS))
Coordinate Reference System (CRS)
101- coordinate based local, regional, or global system used to location geographical entities
(aka Spatial Reference Systems (SRS))
International Terrestrial Reference System (ITRS)
101- a three-dimensional coordinate system with a well-defined origin (the center of mass of
the Earth) and three orthogonal coordinate axes (X,Y,Z)
Map projection
101- transforming coordinated from a curved surface (Earth) to a flat map
Horizontal datum
101- 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)
,Vertical Datum
101- reference point for measuring elevations
NAVD88
101- Gravity based geodetic datum in North America
WGS 84 (World Geodetic System)
101- reference coordinate system used by the Global Positioning System (GPS)
SRID integer
101- Spatial reference system id numbers, including EPSG codes defined by the International
Association of Oil and Gas Producers
types of distortion
101- Distance, Direction, Shape, Area (sometimes bearing and scale)
Mercator Projection- distortions
101- preserves shape and direction, area gets distorted
Mercator Projection
101- projecting the Earth onto a cylinder tangent to a meridian
Azimuthal Projection- distortions
101- distance from center is true, other properties distort with distance
Azimuthal Projection
101- planar or tangent (meaning they are formed when a flat piece of paper is placed on top
of the globe and a light source projects the surrounding areas on to a map.) Either the North
,Pole or the South pole is orientated at the center of the map, giving the viewer an impression
of looking up or down at Earth.
Cylindrical Projection- distortions
101- preserve area and shape, distance gets distorted, especially on upper and lower regions
of the map
Cylindrical Projection
101- 2 types Tangent (1 intersect) and Secant (2 intersects)
Straight meridians and parallels
meridians are equally spaced while parallels are not
Conical Projection- distortions
101- preserves direction and area in limited areas, distorts distance and scale except along
standard parallels
Conic Projections
101- mapped to equally spaced lines by projecting a spherical surface onto a cone
Choosing a Projection- Low LATITUDE, (near Equator)
101- use conical projection
Choosing a Projection- High LATITUDE, Polar Regions
101- use azimuthal planar projections
Choosing a Projection- EXTENT, broad East-West (e.g. USA)
101- use conical projection
Choosing a Projection- EXTENT, broad North-South (e.g. Africa)
, 101- use transverse-case cylindrical projection
Choosing a Projection- THEMATIC, analysis that compares different values in
different locations
101- use an equal-area projection
Discrete features
102- feature has a definable boundary (think, "vector")
continuous phenomena
102- each location is a measure of something, often temperature or elevation (think "raster",
but not always)
Geoid
103- the shape that the surface of the oceans would take under the influence of Earth's
gravitation and rotation alone (absent of the influence of wind or tide)
Mean Sea Level (MSL)
103- is determined by referencing the geoid model which registers ocean's water level at
coastal places using tide gauges
Reference Ellipsoid
103- is a mathematically defined surface that approximates the geoid (a truer model of shape
that geoid)
oblate ellipsoid
Answers
Georeferencing
101- associating a map or image with spatial location
control points
101- points come in pairs that match the spatial location with a point on an unreferenced
image or map
Spatial Reference Systems (SRS)
101- coordinate based local, regional, or global system used to location geographical entities
(aka Coordinate Reference System (CRS))
Coordinate Reference System (CRS)
101- coordinate based local, regional, or global system used to location geographical entities
(aka Spatial Reference Systems (SRS))
International Terrestrial Reference System (ITRS)
101- a three-dimensional coordinate system with a well-defined origin (the center of mass of
the Earth) and three orthogonal coordinate axes (X,Y,Z)
Map projection
101- transforming coordinated from a curved surface (Earth) to a flat map
Horizontal datum
101- 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)
,Vertical Datum
101- reference point for measuring elevations
NAVD88
101- Gravity based geodetic datum in North America
WGS 84 (World Geodetic System)
101- reference coordinate system used by the Global Positioning System (GPS)
SRID integer
101- Spatial reference system id numbers, including EPSG codes defined by the International
Association of Oil and Gas Producers
types of distortion
101- Distance, Direction, Shape, Area (sometimes bearing and scale)
Mercator Projection- distortions
101- preserves shape and direction, area gets distorted
Mercator Projection
101- projecting the Earth onto a cylinder tangent to a meridian
Azimuthal Projection- distortions
101- distance from center is true, other properties distort with distance
Azimuthal Projection
101- planar or tangent (meaning they are formed when a flat piece of paper is placed on top
of the globe and a light source projects the surrounding areas on to a map.) Either the North
,Pole or the South pole is orientated at the center of the map, giving the viewer an impression
of looking up or down at Earth.
Cylindrical Projection- distortions
101- preserve area and shape, distance gets distorted, especially on upper and lower regions
of the map
Cylindrical Projection
101- 2 types Tangent (1 intersect) and Secant (2 intersects)
Straight meridians and parallels
meridians are equally spaced while parallels are not
Conical Projection- distortions
101- preserves direction and area in limited areas, distorts distance and scale except along
standard parallels
Conic Projections
101- mapped to equally spaced lines by projecting a spherical surface onto a cone
Choosing a Projection- Low LATITUDE, (near Equator)
101- use conical projection
Choosing a Projection- High LATITUDE, Polar Regions
101- use azimuthal planar projections
Choosing a Projection- EXTENT, broad East-West (e.g. USA)
101- use conical projection
Choosing a Projection- EXTENT, broad North-South (e.g. Africa)
, 101- use transverse-case cylindrical projection
Choosing a Projection- THEMATIC, analysis that compares different values in
different locations
101- use an equal-area projection
Discrete features
102- feature has a definable boundary (think, "vector")
continuous phenomena
102- each location is a measure of something, often temperature or elevation (think "raster",
but not always)
Geoid
103- the shape that the surface of the oceans would take under the influence of Earth's
gravitation and rotation alone (absent of the influence of wind or tide)
Mean Sea Level (MSL)
103- is determined by referencing the geoid model which registers ocean's water level at
coastal places using tide gauges
Reference Ellipsoid
103- is a mathematically defined surface that approximates the geoid (a truer model of shape
that geoid)
oblate ellipsoid
