Mastering ArcGIS 7th Edition (PDF)
Always use an underscore instead of a space. It is assumed that most students using this book already have a background of discipline-specific knowledge and skills upon which to draw and are seeking to apply geospatial techniques within their own knowledge domains. Give at least three reasons for your choice. At times, the abundance of tasks and the flexibility of options may be overwhelming. The vector model is also a compact way of storing data, typically requiring a tenth of the space of a raster with similar information. The best one to use depends on the purpose of the map, which is why data are stored and used in many coordinate systems instead of just one. An equal area coordinate system displays accurate areas.
All commands and actions, such as adding layers or creating a scale bar, occur in the active frame. Maps derived from aerial photography or satellite imagery can vary widely in geometric quality based on factors such as the scale of the image, the resolution of the image, imperfections and distortions in the imaging system, and the types of corrections applied to the image. Ensuring that every person has the most recent copy is a difficult task. The videos are intended as an alternate learning strategy. Dubure, Colleen Garrity, Raymond Greene, Eileen Johnson, James Leonard, and Tao Tang provided detailed and helpful comments, and the book is better than it would have been without their efforts. The view zooms out with the point clicked at the center.
On your own computer, you will generally have both read and write access read-write access to all files. It does not delete it from the hard drive. A layer is like a cooking recipe—it describes where to find the data file the ingredients and how to display it the cooking instructions. Today, operating systems are more flexible, but not all software applications evolve at the same rate or follow the same conventions. Importing New Jersey to a message. Geodatabases A geodatabase can contain many different objects, including feature classes, networks, tables, rasters, Geodatabase and topology. They are numbered in the text for easy reference.
For a company or small agency, the city and state should be included. Since then, the development of the Internet and the rapidly advancing field of computer hardware have been driving some significant changes in the industry. In this case, the first person who opened the file had read-write access, but the second person only had read access. Is there a feature dataset in the usdata geodatabase? These icons control the appearance of the Table of Contents and how it arranges the layers. Translated into Latin, it became the core of Western geography, influencing cartographic giants such as Gerhard Mercator, who published his famous world map in 1569. Consider the 90-meter resolution roads raster in Figure 1.
When converted to a raster, the number 1, 2, or 3 is used to represent each road that passes through a cell. Labels are another property of a layer. Uppercase letters were not interchangeable with lowercase letters. ¾ Data compiled for a project must be taken from data with source scales suitable for the geographic area and intended purpose of the geodatabase. Creating a landslides hazards map provides a simple example. Chapters 1—11 follow a roughly project-based sequence: data compilation, data exploration and mapping, tables and basic editing, and analysis.
Shapefiles Shapefiles are spaghetti data models containing a feature class composed of points, lines or polygons, but never a mixture. What kind of information is needed to support decision making? The higher the resolution, the more precisely the data can be represented. In 1859, French photographer and balloonist Gaspard Felix Tournachon founded the art of remote sensing by carrying large-format cameras into the sky. A few broad categories can be defined. Shapefile in Windows Explorer Shapefile in ArcCatalog Fig.
Click the gtoposhd raster in the Catalog Fig. A data frame projects all its layers on the fly, so all layers in a data frame are not necessarily in the same coordinate system. A typical page-size map of the state would have a scale of about 1:2,000,000. In some cases, this may be different from the originator of the data. Data created internally within the workplace need not be cited, although often the company name or logo will appear on the map. You do not have as much control of a map service as your own layers, but a few display options can be set. Internet data services Many organizations make data available over the Internet.
The following is the difference between feature, feature class, and feature dataset: Feature: Feature means a single spatial body, point, polygon or line. Surveyors and land-planning professionals contribute precise measurement of boundaries. The raster model has the benefit of simplicity. ArcToolbox and a model ArcMap documents ArcMap creates map documents, a collection of spatial data layers and tables and their properties. The resolution in New York City is sub-meter, but it will not be that good everywhere. New data sets emerge; old ones become unavailable or are moved to new locations. Second, the linked attribute table provides great flexibility in the number and type of attributes that can be stored about each feature.