GIS File Types

Question 1

What are the Components of a Polygon?

Answer 1

-Centroid, area, perimeter
-The centroid does not have to be inside the polygon (think of a multipart feature)

Question 2

What are the Shapefile’s Necessary Files?

Answer 2

-.shp: feature geometry
-.dbf: attributes
-.shx: spatial index

Question 3

What are the CAD Formats?

Answer 3

AutoCAD: DXF, DWG
Microstation: DGN

Question 4

What is Geography Markup Language (GML)?

Answer 4

Designed to encode unique geographic features

Question 5

What are some Raster Files Types?

Answer 5

.tiff, .jpg, .bmp, .sid

Question 6

What is a Triangulated Irregular Network (TIN)?

Answer 6

-Vector based
-Represent surface shapes
-Used for very detailed modeling of small areas

Question 7

What do ASCII Files (.csv, .txt) need?

Answer 7

-Need to have column headers in the first row
-Need to have either: Coordinates, Addresses, An attribute to join to a GIS dataset

Question 8

What is the XLS(X) format?

Answer 8

-Spreadsheet, not a database
-First row determines data types
-No spaces or special characters allowed in the column names

Question 9

What is the DBF format?

Answer 9

-dBase format, used by shapefiles, standard exchange format
-Limited to 10 characters in the column name
-No spaces or special characters in the column names
-DBF to Arc keeps the field types

Question 10

What are Digital Elevation Models (DEMs)?

Answer 10

Represent bare earth elevations. 3D Elevation Project (3DEP) made LiDAR data the standard for new elevation data.

Question 11

What are the advantages of web services?

Answer 11

-Fast, direct access to GIS data (no download, unzip)
-Supported by many mapping applications

Question 12

What is SOAP/REST?

Answer 12

-Simple Object Access Protocol (SOAP): Older technology, XML only, more security options, highly extensible
-REpresentational State Transfer (REST): Supports XML and JSON, Simpler structure

Question 13

What are the Data Exchange Methods?

Answer 13

-File-based data exchange between users: Export to exchange format or compress a gdb (zip or tar file), put on FTP site, SFTP, Web Portal, or Disk for sharing
-Data exchange between software: Softwares exchange data as needed
-Web service data exchange: A web service is shared by one user and consumed by others through a web server. No data is downloaded

Question 14

What is the generic term for a geodatabase?

Answer 14

Object oriented relational database

Question 15

What is the generic term for shapefile?

Answer 15

Vector relational database

Question 16

What are the 3D data types?

Answer 16

-3D feature data
-Raster
-TINs (wire frame)
-Multipatch
-Point cloud