Geospatial Data Fundamentals

Question 1

Spatial Model

Answer 1

basic properties and process for a set of spatial features

Question 2

Cartographic Model

Answer 2

temporally static, combined spatial datasets, operations and functions for problem-solving

Question 3

Spatio-temporal Model

Answer 3

Dynamics in space and time, and time-driven processes

Question 4

Network Model

Answer 4

modeling of resources (flow, accumulation) as limited to networks

Question 5

Data models (Goodchild)

Answer 5

entities and fields as conceptual models

Question 6

Static Modeling (Goodchild)

Answer 6

Taking inputs to transform them into outputs using sets of tools and functions

Question 7

Dynamic Modeling (Goodchild)

Answer 7

An iterative model with sets of initial conditions that applies transformations to obtain a series of predictions at time intervals

Question 8

Passive and prescriptive data models (DeMers)

Answer 8

passive models are like description of the study area; Prescriptive models are active, imposing best solutions.

Question 9

Vector

Answer 9

A coordinate-based data model that represents points, lines, and polygons.

Question 10

Points

Answer 10

Discrete locations on the ground, and represented by a coordinate pair

Question 11

Lines

Answer 11

Linear features, such as rivers, roads, and transmission cables, are composed of vertices (beginning and ending at vertices), represented by an ordered list of vertices

Question 12

Polygon

Answer 12

Form bounded areas, such as islands, land masses, and water features, that are composed of nodes and vertices, with the start node the same as the end node.

Question 13

Raster

Answer 13

Composed of rectangular arrays of regularly spaced square grid cells. Each cell has a value (attribute). It can be single or multiple bands, with each cell having one attribute value. And the raster coordinates are stored by ordering the matrix.

Question 14

Pixel

Answer 14

smallest resolvable piece of the scanned image. It’s always a cell but a cell is not always a pixel.

Question 15

Geodatabase

Answer 15

It’s an object-oriented spatial model that includes feature classes, feature datasets, nom-spatial tables, as well as complex components such as topology, relationship classes, and geometric networks.

Question 16

Relationship classes

Answer 16

model real-world relationships that exist between objects such as parcels and buildings

Question 17

Grid

Answer 17

Parallel and perpendicular lines for reference as a map projection or coordinate-system

Question 18

TIN

Answer 18

Triangulated irregular network - it portions vector data into contiguous, non-overlapping triangles. It creates Delaunay triangles.

Question 19

Advantage of TIN

Answer 19

It’s best for small areas with high-precision elevation data, and it’s more efficient storage than DEM or contour line.

Question 20

Topological

Answer 20

features that need to be connected using specific rules

Question 21

Hierarchical

Answer 21

database that stores related information in a tree-like structure. And records can be traced from parent records to a root record.

Question 22

Network

Answer 22

A collection of topologically connected network elements (edges, junctions, turns). And each element is associated with a collection of network attributes

Question 23

Object-oriented data

Answer 23

data management structure stores data as objects (classes) instead of rows and tables as a relational database. The examples include SQL Server, Oracle, and PostgreSQL.

Question 24

Type of relationships

Answer 24

one-to-one; one-to-many; many-to-many

Question 25

One-to-one relationship

Answer 25

Each object of the origin table can be related to zero or one object of the destination table

Question 26

One-to-many relationship

Answer 26

Each object in the origin table can be related to the multiple objects in the destination table

Question 27

Many-to-many relationship

Answer 27

Multiple objects of the origin table can be related to multiple objects of the destination table

Question 28

Typological relationships

Answer 28

Equal, disjoint, intersects, touches, contains, covers, covered by, within, crosses, overlaps

Question 29

Equals

Answer 29

Two features are typologically equal: a = b

Question 30

Disjoint

Answer 30

Two features have no point in common: a ∩ b = ∅

Question 31

Intersects

Answer 31

Two features have some common interior points: a ∩ b ≠ ∅

Question 32

Touches

Answer 32

One feature touches another with at least one boundary point in common: (a ∩ b ≠ ∅) ∧ (aο ∩ bο = ∅)

Question 33

Contains

Answer 33

a ∩ b = b

Question 34

Covers

Answer 34

Every point of one feature is a point of another: aο ∩ b = b

Question 35

Covered by

Answer 35

reverse of the “covers”

Question 36

Within

Answer 36

a ∩ b = a, opposite of “Contains”

Question 37

Crosses

Answer 37

a crosses b at some point

Question 38

Overlaps

Answer 38

a and b have common interior points

Question 39

Geometric Accuracy

Answer 39

the closeness of a measurement to its true value

Question 40

Root Mean Squared Error (RMS)

Answer 40

A calculation to describe the difference between the measurement and the true value.

Question 41

Thematic Accuracy

Answer 41

The accuracy of non-spatial data, such as the street name accurate on a street feature class

Question 42

Resolution

Answer 42

The smallest separation between two coordinate values (for raster, resolution refers to the cell size)

Question 43

Precision

Answer 43

The level of measurement and exactness of attribute data

Question 44

Fitness for use

Answer 44

Does the data fulfill the needs of the project?

Question 45

Confusion matrix

Answer 45

assesses accuracy of image classification based on additional ground truths

Question 46

Quality Assurance

Answer 46

The process that orients and focuses on defect prevention. It applies the Managerial Tool/Peroid Audits, which is the establishment of a good quality management system and assessment of its adequacy

Question 47

Quality Control

Answer 47

The product focuses on defect identification. Such as the corrective tool, which finds and eliminate sources of quality problems through tools and equipment

Question 48

Imprecision

Answer 48

All data is taken from a 3D globe and transferred to a 2D surface through spatial transformations (projection and datums) which cause distortions with the data

Question 49

Uncertainty

Answer 49

The GIS data that was created/collected at a certain point of time, may already be out of date. This implies the differences between the GIS and the real world. It may be visible from the original data or measuring that data; it may result from the assumptions made when creating the data; It’s related to the model structure, including retrieval errors, sampling error, and inadequate ground observations.

Question 50

Data Resolution

Answer 50

the cell size of a raster (the area covered by the ground represented by just one cell)

Question 51

Validation

Answer 51

To ensure the accuracy of the data is preserved, which uses ground observations to ensure data accuracy, or the data can be compared to model-generated data (which is less accurate).

Question 52

Temporal

Answer 52

data that represents a state in time, for example, the rain fall for one day.

Question 53

FGDC

Answer 53

Federal Geographic Data Committee: who, what, when, where why and how. Its format includes the title, abstract and date, geographic extent and projection info, attribute label definitions, and domain values.

Question 54

CSDGM

Answer 54

Content Standard for Digital Geospatial Metadata

Question 55

OGC

Answer 55

Open GIS Consortium. It describes the basic data model for holding geographic data.