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Esri ArcGIS Desktop Professional Certification Study Guide. Mike Flanagan
Читать онлайн.Название Esri ArcGIS Desktop Professional Certification Study Guide
Год выпуска 0
isbn 9781589485365
Автор произведения Mike Flanagan
Жанр Программы
Издательство Ingram
Help > Data > Data types > Relationship classes (and all subtopics)
Gain a thorough understanding of these ArcMap Help topics:
Manage data > Data types > Relationships and related objects (and all subtopics)
Manage data > Data types > Tables > Joining tables by spatial query (and all subtopics)
Topology
Topology is a collection of rules and relationships that define the coincidence between point, line, and polygon features. You can create a topology to preserve the spatial relationships between features in your data. You can also use topology tools to validate and fix any potential errors. Topology includes rules that help ensure data quality; for example, you can set topology rules that will help you minimize gaps or overlaps among coincident features or simultaneously edit features that overlap or touch.
Two types of topology are supported in ArcGIS: map topology and geodatabase topology. Map topology is available at all license levels, whereas geodatabase topology requires an ArcGIS Standard or Advanced license. Map topology does not require any setup and can be used to maintain the coincidence, covering, and crossing of any visible features in your maps. Geodatabase topology is stored as part of a feature dataset and includes a collection of rules and editing tools that enable your geodatabase to accurately model the geometric relationships between features in one or more of the participating feature classes.
ArcGIS includes geoprocessing tools that you can use to build, analyze, manage, and validate topologies. For example, you can use tools in the Topology toolset to build and load data into a topology. Then you can define rules to edit and maintain the participating features. Once these rules are in place, you can run a validation against the topology, and ArcGIS will identify areas that require edits or that have broken your rules. If a predefined fix is available, you can quickly fix the error using functionality in the user interface; if not, you can modify the features using modify tools and can validate the areas again to ensure that your changes have fixed the error.
Prepare
These topics in the documentation provide details about topology.
Gain a thorough understanding of these ArcGIS Pro Help topics:
Help > Data > Edit geographic data > Modify topology >Introduction to editing topologyMap topologyGeodatabase topology (and all subtopics)
Gain a thorough understanding of these ArcMap Help topics:
Manage data > Data types > Topologies (and all subtopics)
Practice
Take these web courses to get more hands-on experience:
Getting Started with the Geodatabase
Working with Geodatabase Domains and Subtypes in ArcGIS
Getting Started with Geodatabase Topology
Skills check-in
Now that you have explored these concepts, it is time to check in! This is not an exhaustive list of topics that are covered on the exam, but it references the types of tasks a qualified candidate should be able to perform. If there is anything you cannot confidently do, review those concepts until you can.
I can:
Given requirements for a specific project, design a file geodatabase to support the project (for example, the behavior or functionality of the geodatabase, types of datasets).
Determine the set of simple features, tables, or complex feature types necessary to support a use case.
Given required relationships, design and implement key fields and relationship classes with required cardinality.
Determine the objects participating in topologies, networks, and routes.
Create and manage complex data types (for example, topology, network dataset, annotations, routes).
Generate domains from tables of clerical research.
Select appropriate data formats for an intended use
A geodatabase is the ideal place to store simple vector, raster, and tabular data, but it is not limited to simple data. Geodatabases are also designed to support complex data elements that you can use to manage high-resolution data, massively large point datasets, and large collections of high-resolution imagery. For example, a geodatabase is an ideal place to store 3D surfaces or multispectral and multidimensional data. This section covers data formats that you can use to manage massively large point datasets and large collections of high-resolution imagery. This skill has two parts: (1) managing high-resolution point data and (2) mosaic datasets.
Managing high-resolution point data
One of the most common data formats used for storing and visualizing high-resolution point data is LAS. LAS is an American Society for Photogrammetry and Remote Sensing (ASPRS)–derived open file format used for the storage and interchange of lidar data. Lidar data gives GIS professionals access to a densely sampled point cloud that reflects the earth’s surface at extremely high resolutions. ArcGIS provides LAS file support using LAS datasets, mosaic datasets, and terrain datasets.
A LAS dataset gives you access to large volumes of lidar data by storing a reference to source files. This functionality allows you to view the data in its native format, offering support for several thousand LAS files at a time. Because the data is referenced rather than stored, it can be constructed quickly and can be used to provide a quick look at the statistics and extent of the participating LAS files. LAS datasets can also be converted into a TIN-based surface for visualization, making them a great complement to your terrain dataset workflows. For example, you could use a LAS dataset to perform a quality check on your lidar data before migrating it into a terrain dataset. LAS datasets require the ArcGIS 3D Analyst™ or ArcGIS Spatial Analyst™ extension, or an ArcGIS Desktop Standard (or higher) license.
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