Spatial Data INput Textbook: Chapter 5

Learning Objectives c) Describe Spatial Data Input List and explain methods for entering spatial data (coordinates) into the GIS: digitizing, scanning, Global Positioning Systems (GPS), conversion software, survey instruments

Spatial Data INPUT Step 1: Database Design Document Step 2: Find Data Step 3: Input data into the computer Step 4: Spatial data editing and manipulation Step 5: Spatial data model verification

Step 1: Database Design Document Spatial Data layers

Step 2: Find Data Be careful…. Quality, screen shots vs. real data Accuracy Scale …

Step 3: Input data www – open data, often in shape files Data Conversion File Transfer (Web data) BC TRIM data (maps BC)

City of Vancouver http://vancouver.ca/your-government/open- data-catalogue.aspx

GPS

Surveying / COGO Theodolite

Digitizing Points Lines polygons

Air Photo On screen digitizing

Scanning

Keyboard Entry

Step 4: Spatial Data Editing and Manipulation topology verification project / transform edgematching rubber sheeting / geo-referencing

a) Topology verification: errors Undershoots Pseudo nodes No labels overshoots duplicate labels

a) Topology verification: fixed Extend Undershoot Delete Pseudo nodes Add label clip overshoots delete duplicate labels

b) Project / Transform Project from one projection to another Albers Equal area to Lambert Conformal Transform NAD27-NAD83

c) Edgematching

d) Geo-referencing (rubber sheeting) Taking historic airphoto and accurate city streets: making them fit

Step 5: Spatial Data Verified

Midterm: Short answer, 45 minutes Labs 1, 2 Lectures up to here, not tabular data Textbook chapters 1, 2, 3, 5 Except: Chapter 2: p 31- 34 before Topology Box 2.6, 2.8, 2.9, 2.10 Chapter 3 Box 3.5, building computer worlds on p.64-p.68 Generally, terms and concepts that we did not cover in class