LDA 150 Lecture Questions

What does a Geographic Information System (GIS) enable users to accomplish?

Capturing, storing, querying, analyzing, and displaying geospatial data.

How does a vector data model differ from a raster data model?

vector data model: uses points, lines and polygons and their x-, y-coordinates to represent discrete features.

raster data model uses a grid and grid cells to represent continuous features such as elevation and precipitation

If a data set’s features have x coordinates between –180 and +180, what is the coordinate system

likely to be? In what units are the coordinates?

UTM, degrees latitude

Can you convert a vector to a raster layer?

Spatial analyst toolbox to convert

Explain why conic projections usually conserve area and distance but cylindrical projections typically preserve direction.

Conic: mimic Earth, latitudes become smaller moving from the equator to the poles.

Cylindrical: meridans are always north.

Select the best definition of the term "spatial reference".
A) the complete description of a coordinate system's properties and parameters
B) the choice of geographic coordinate system used for a data set
C) the original source of a specific map projection as defined by its inventor
D) the coordinate system chosen for the map during on the fly projection

A

You have obtained data in a WGS84, UTM coordinate system and wish to include it in a project using

NAD83(2011), also in a UTM coordinate system, collected via GPS a decade later. Your allowable

error is 1 m. Which of the following are the minimum operations to convert your data, and still meet

your accuracy/error requirement.

A) Apply a projection from UTM to geographic coordinates, apply an appropriate

datum transformation from WGS84 to NAD83(2011), and then project from

geographic coordinates to UTM coordinates

B) Project from NAD83(2011) UTM coordinates to geographic coordinates, then

project from geographic coordinates to NAD83(2011) UTM coordinates

C) Apply a datum transformation from NAD83(2011) UTM to WGS84 UTM

coordinates

D) None of these

A

What is GIS?

A computer software/program that is used for storing, analyzing, and visualizing geospatial data.

What is a datum?

A set of parameters that describes the positions of features on Earth’s surface. Comprised of a reference ellipsoid, geoid, and coordinate system. Vertical datums relate to elevation; Horizontal datums relate to location.

In the context of Geographic Information Systems (GIS), which component is primarily responsible for the interpretation and presentation of GIS results?

People

What are the components of GIS?

hardware (computers), software (programs), and People, Data, Organizations

What is geospatial data?

data that has been geo-referenced to a specfic location on earth’s surface

What features make a good map?

1. Title

2. Legend

3. Scale Bar

4. North Arrow

5. Projection

6. Credits

Which factor is most critical in deciding between proprietary GIS software like ArcGIS and open-source GIS software like QGIS?

Budget constraints, licensing costs and security

A closed figure composed of x-y coordinates is called a_______

Polygon

The basic element of data storage in a raster is called a_________.

Cell or Pixel

When a data set is placed into a map, it is called a_________.

Layer

A raster portraying a_________ is an example of continuous data.

Precipitation / Elevation

Degrees of latitude and longitude measure...

angles from the center of an ellipsoid.

You are planning a hike. You measure the trail on a 1:24,000 scale map and discover that it is 30 cm long. How long is the hike in kilometers?

7.2 km [cm —> meters —> km]

Information about a data set, such as who created it and why, is called_________.

Metadata

Which one of the ArcGIS family of products is most tightly coupled to ArcGIS Online?

A) ArcView

B) ArcMap

C) ArcGIS Pro

D) ArcInfo Workstation

E) ArcCatalog

C) ArcGIS Pro

What distinguishes a Geographic Coordinate System from a Cartesian coordinate system?

Longitude and latitude are angular systems.

How did the advent of satellites and the computer revolution alter the approach to geodetic datums from the 1970s to the 1990s?

Datums became globally recalculated and incorporated tectonic plate movements.

The distance represented by a degree at the equator is approximately

110 km / 111 km

The best choice of a geographic coordinate system for a world map would usually be_________.

an earth-centered datum

The geometric figure that most accurately represents the earth's surface is the_________.

Geoid

20. 7. The most precise positional measurements must record the epoch, or time of measurement to

account for continental drift.

A) True

B) False

True

It is best practice to convert all data used in a GIS project to the same datum and coordinate system

A) True

B) False

True

Which one of the following statements is TRUE?

a. A point feature contains only one node.

b. A polygon feature contains nodes but not vertices.

c. A polygon feature contains vertices but not nodes.

d. A line feature contains nodes but not vertices.

C. A polygon feature contains vertices but not nodes.

Select the example that best characterizes the term "multipart feature".

a. A feature with multiple records and one polygon.

b. A feature with multiple pixels stored together.

c. A feature with multiple polygons in one record.

d. A feature that appears multiple times in different feature classes.

c. A feature with multiple polygons in one record.

A position in the NAD83 datum typically differs by up to 1 to 2 meters from that same position in the

WGS84 datum.

A) True

B) False

True

Which one of the following is NOT a characteristic of GIS data?

a. GIS data files may be very large.

b. GIS data files may come from many sources and in many formats.

c. GIS data files are never shared by multiple users.

d. GIS data files do not always follow the latest computer conventions.

c. GIS data files are never shared by multiple users.

If choosing a datum for a coordinate system in the conterminous UnitedStates, which one of the following is usually the best choice and why?

NAD 1983 (2011) because it is the most recent

A conic map projection best preserves the combined properties

of_________.

A)shape and area

B)shape and direction

C)distance and shape

D)distance and area

E)distance, shape, direction, and area

D. distance and area

Two GPS units lying next to each other are set to collect locations in NAD 1983 UTM Zone10 and NAD 1927 UTM Zone 10 respectively. Which statement best characterizes the readings given by the two units?

A)The locations reported by both units won't be accurate.

B)The locations reported by both units should the same.

C)The locations reported by the units may differ by a couple hundred meters.

D)The locations reported by the units won't differ by more than a few meters.

C)The locations reported by the units may differ by a couple hundred meters.

If you are creating a map of the United States comparing the areas of

different weather systems, the best projection to use would be_________.

A) a geographic coordinate system

B) a conic projection

C) a cylindrical projection

D) a State Plane coordinate system

E) a UTM coordinate system

B) a conic projection

Select all the statements that are true about vertical datums.

A) Datums can be established through trigonometric leveling

B) Mean sea level corresponds to our current vertical datum

C) Geoid models have improved through time

D) NGVD29 was matched to more tidal stations than NAVD88

A, C, D

Mean sea level varies across globe.

Which one of the following projections is not used in State Plane coordinate systems?

A)Transverse Mercator

B)Lambert Conformal Conic

C)Oblique Mercator

D)Universal Transverse Mercator

D) Universal Transverse Mercator (UTM)

Two layers are being displayed in a map view, which has been set to a State Plane coordinate system with units of feet. The box showing the cursor location lists the values in miles. One layer is stored in a GCS with units of degrees. The second layer is stored in UTM with units of meters. What are the map units?

A)degrees

B)meters

C)feet

D)miles

C) feet

Select the best definition of the term "spatial reference".

A)the complete description of a coordinate system's properties and parameters.

B)the choice of geographic coordinate system used for a data set

C)the original source of a specific map projection as defined by its inventor

D)the coordinate system chosen for the map during on the fly projection

A) the complete description of a coordinate system's properties and parameters

A projection from on coordinate system to another projected coordinate system must involve a datum
transformation.
A) True
B) False

B. False

Explain the difference between NAD27 and NAD83.

NAD27 is a local datum based on a center of mass in Kansas. 866 ellipsoid, whereas NAD83 is a geocentric datum based on earth’s center of mass. NAD83 is a more accurate reference than NAD27.

What is a datum?

A datum is a mathematical model of the Earth, which serves as the reference forcalculating the geographic coordinate.

What is WGS84?

Developed by the U.S. Department of Defense, WGS84 is a global reference system for supporting positioning and navigation. It is the datum for GPS readings.

Explain the importance of map projection.

- use of two-dimensional maps, either paper or digital, instead of a globe

- to work with plane or projected coordinates rather than longitude and latitude values

- to do computations with geographic coordinates that are more complex

Explain the difference between the standard line and the central line

A standard line refers to the line of tangency between the projection surface and the reference globe. In other words, there is no projection distortion along a standard line. The central lines (i.e., the central parallel and meridian) define the center of a map projection.

Explain how a UTM zone is defined in terms of its central meridian, standard meridian, and scale factor

A UTM zone is mapped onto a secant case transverse Mercator projection, with a scale factor of 1 at the central meridian. The standard meridians are 180 kilometers to the east and west of the central meridians. 60 zones that are 6 degrees each, that minimize distortion in area, shape, and distance.

• Not good for US projections (long East to West maps).

Describe the four types of map projections by the preserved property

A conformal projection preserves local angles and shapes (weather/navigation).

A equal area or equivalent projection represents areas in correct relative size.

An equidistant projection maintains consistency of scale along certain lines.

An azimuthal projection retains certain accurate directions

Why should one avoid using spaces and special characters like $#% in folder names?

A) These characters damage the computer operating system.
B) Not all software packages work correctly when they encounter
these names.
C) Some users may be offended when they see these characters

B) Not all software packages work correctly when they encounter
these names.

Why is it advantageous to separate downloaded and in-production files from permanent datasets?
A) Because folders should only contain one data type.
B) Because you can damage existing datasets by downloading to
the same folder.
C) Because data can only be downloaded to one folder on the
computer.
D) Because it facilitates cleaning temporary data from folders with
minimal risk to permanent data.

D) Because it facilitates cleaning temporary data from folders with

minimal risk to permanent data.

On Windows computers, why should GIS data be stored on the main C:\ drive rather than the default user

library folder or Desktop?

A) Because the software does not always work correctly when

accessing data under the Library folders or on the Windows

Desktop.

B) Because the Library folders and Windows Desktop permit

spaces in filenames and the C:\ drive does not.

C) Because there is more room on the C:\ drive.

D) Because on a network, the Library folders can get mixed up

between different users

A) Because the software does not always work correctly when

accessing data under the Library folders or on the Windows

Desktop.

Data found in ArcGIS Online can be downloaded and stored in a local folder_________.

A) always

B) sometimes

C) never

B) sometimes

If a club is creating a map for hikers to use in the backcountry, the target source scale for downloaded data
would be about_________.
A) 1:20 million
B) 1:2 million
C) 1:200,000
D) 1:20,000

D) 1:20,000

When using x-y fields in a table to create points on a map, it is important to specify the coordinate system

as_________.

A) the same coordinate system used in the map view

B) the coordinate system reflected in the table's x-y fields

C) the desired coordinate system to store the final feature class

D) a geographic coordinate system

E) a projected coordinate system

B) the coordinate system reflected in the table's x-y fields

When importing data for your home state, the Clip tool would most likely be needed to extract_________.

A) counties

B) zip codes

C) cities

D) rivers

D) rivers

The_________ tool merges features together if they share the same attribute values in a specified field or list of fields.

A) intersect

B) buffer

C) erase

D) dissolve

D) dissolve

Select the definition of the term "feature dataset".

A) a collection of feature classes related to each other in some way

B) a collection of features that share an attribute table and

geometry type

C) a collection of geodatabases containing feature for the same

geographic area

D) a collection of rasters that share the same coordinate system

A) a collection of feature classes related to each other in some way

Feature classes in a feature dataset must_________.

A) all have the same geometry type

B) all have the same coordinate system

C) all participate in a planar topology

D) all have the same prefix in the feature class name

B) all have the same coordinate system

Which one of the following describes an advantage of shapefiles over geodatabases?

A) Shapefiles can be read by many different GIS programs and are now commonly used to share data.

B) Shapefiles offer automatic tracking and updating of geometry attributes such as polygon areas or line lengths.

C) Shapefiles can utilize topology rules for finding and fixing topology errors.

D) Shapefiles can incorporate subtypes and domains for advanced functionality.

A) Shapefiles can be read by many different GIS programs and are now commonly used to share data.

Which one of the following would be most likely to use an enterprise geodatabase?

A) a city planning department with multiple divisions editing the same

data

B) a group of students working on a class project

C) a doctoral student developing large raster datasets for a dissertation

D) an academic departing needing to provide access to a large number

of static datasets

A) a city planning department with multiple divisions editing the same

data

Which one of the following can a geodatabase NOT store?

A) feature classes

B) rasters

C) coverages

D) tables

E) feature datasets

C) coverages

It is equally satisfactory to use Windows to manage (copy, rename, delete) GIS data as to use the tools and Catalog

in Pro to do it.

A) True

B) False

B) False

The project (.aprx) file_________.

A) stores all datasets associated with the project

B) keeps track of the data, settings, and resources needed to make the

project work

C) includes the home geodatabase and project folder

D) is stored in the project home geodatabase

B) keeps track of the data, settings, and resources needed to make the

project work

Which ONE of the following statements is TRUE?

A) Changes made to a layer in ArcGIS Pro modify the file of the

associated feature class.

B) A layer points to a feature class and contains properties that can be

set for the feature class.

C) A feature class contains the spatial features and a layer contains the

attribute data.

D) A layer contains both the spatial and attribute information for a

dataset.

B) A layer points to a feature class and contains properties that can be

set for the feature class.

Which of the following is a legal pathname for GIS data?

A) C:\my_data\mgisdata\usa\roadnum.shp

B) C:\my data\southdakota\custer\roads.shp

C) D:\europe\census2000\euc$bounds\france.shp

D) D:\gisfolder\oregon\water_data\stream#.shp

A) C:\my_data\mgisdata\usa\roadnum.shp

Changes made to layers in the Contents pane usually make permanent changes to the stored data files.

A) True

B) False

B) False

Select the definition of a "feature ID" or "FID".

A) A unique integer used to identify a feature in an attribute table.

B) A name stored in an attribute table, such as Utah or Denver.

C) A special field "found in only in shapefiles" that store parcel

data.

D) An ID number assigned to each feature by the user.

A) A unique integer used to identify a feature in an attribute table.

Name the three types of simple features used in GIS and their geometric properties.

A point has 0 dimension and has only the property of location. A line is one-dimensional and has the
property of length. And a polygon is two-dimensional and has the properties of area (size) and perimeter (length).

Explain the importance of topology in GIS.

1. Ensures data quality, such as lines meeting perfectly
   and polygons closed properly.

2. Enhance certain types of GIS analysis such as geocoding and traffic volume analysis.

3. Topological relationships between spatial features allow GIS
   users to perform spatial data queries.

What are the main advantages of using shapefiles?

1. Display more rapidly on the computer monitor.

2. Shapefiles are nonproprietary and interoperable, meaning that they can be used across different software packages.

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Describe geodatabases, feature dataset, and feature class relationship.

Form a hierarchical structure. A geodatabase can contain one or more feature datasets, and a feature dataset can store one or more feature classes that share the same coordinate system and area extent.