Arc GIS Data Reviewer Assessing Positional Accuracy Roslyn

Arc. GIS Data Reviewer: Assessing Positional Accuracy Roslyn Dunn

What is Arc. GIS Data Reviewer? Data Quality Management for Arc. GIS • • • Provides - Rule-based validation - Interactive tools - Track errors Validate For individuals and enterprise - Saves time/money - Less rework For multiple domains - Configurable - Extendable Enterprise Workflow Summarize Review Arc. GIS Data Reviewer: Assessing Positional Accuracy

What is Arc. GIS Data Reviewer? Data quality management in the Arc. GIS platform • Data Reviewer for Desktop - Arc. Map - Arc. GIS Pro Desktop Web Device Web GIS • Data Reviewer for Server - • • Standard or higher Arc. GIS Online Portal Data Reviewer API - Java. Script - FLEX Web App. Builder for Arc. GIS Server Online Content and Services Arc. GIS Data Reviewer: Assessing Positional Accuracy

Arc. GIS Data Reviewer: Assessing Positional Accuracy Forms of Geospatial Data Accuracy • Spatial (position, geometry, topology) • Attributional (correctness of attributes) • Spectral (band depth) • Temporal (appropriate date) • Radiometric (capture piece of electromagnetic spectrum) Arc. GIS Data Reviewer: Assessing Positional Accuracy

Arc. GIS Data Reviewer: Assessing Positional Accuracy Concepts • Data needs to be in the “right” place for intended purpose - Usually scale-dependent to some degree • All else being equal, less accurate is less valuable • Data products usually need to conform to a specification - • ASPRS Positional Accuracy Standards November 2014 - Orthoimagery - Digital Planimetric Data - Digital Elevation Data DMA - Error Theory as Applied to Mapping, Charting, and Geodesy Arc. GIS Data Reviewer: Assessing Positional Accuracy

Arc. GIS Data Reviewer: Assessing Positional Accuracy Definition of Terms • Accuracy - The closeness of the best estimated value obtained by the measurements to the “true” value of the quantity measured - • How well does the measured quantity compare to the “true” value? Positional Accuracy - The Quantifiable value that represents the positional difference between two geospatial layers or between a geospatial layer and reality • Circular Error (CE) is an error measurement for both X & Y • Linear Error (LE) is generally an error measurement for Z (elevation) • RMSE is a statistical measurement of the variance between the residual values Arc. GIS Data Reviewer: Assessing Positional Accuracy

Arc. GIS Data Reviewer: Assessing Positional Accuracy Definition of Terms • Circular Error – a two-dimensional error measure (X, Y) • CE 90, 95, 99 - The radial error which n% of all errors in a circular distribution will not exceed - Circular error at n% confidence level - e. g. If CE 90 = 2. 0 Meters then we are 90% confident that the measurement lies somewhere within a circle with a radius of 2. 0 Meters i. e. we’re 90% sure the error won’t be more than 2. 0 Meters Arc. GIS Data Reviewer: Assessing Positional Accuracy

Arc. GIS Data Reviewer: Assessing Positional Accuracy Definition of Terms • Linear Error – a one-dimensional error measure (z) - • A measure of the vertical accuracy of the terrain (e. g. DEM or TIN) The difference between the true or known value and the measured or derived value • LE 90, 95, 99 - Linear error at n% confidence level - e. g. If LE 95 = 10 Meters then we are 95% confident that the “true” elevation measurement is within 10 Meters Arc. GIS Data Reviewer: Assessing Positional Accuracy

Arc. GIS Data Reviewer: Assessing Positional Accuracy Assessment Tool (PAAT) • PAAT Tool - Part of GIS Data Reviewer • Created with requirements gathered from NGA • Determine accuracy of - Imagery - Rasters - Vectors Arc. GIS Data Reviewer: Assessing Positional Accuracy

Arc. GIS Data Reviewer: Assessing Positional Accuracy Assessment Tool (PAAT) Reporting • NGA standard or USGS standard • CE 90, 95, 99 • LE 90, 95, 99 (for DEMs or TINs) • RMSE • Absolute or relative Arc. GIS Data Reviewer: Assessing Positional Accuracy

Arc. GIS Data Reviewer: Assessing Positional Accuracy Assessment Tool (PAAT) Outputs • Text report • Optional outputs: - Accuracy attribute populated (if assessing vectors) - - XML Metadata - ISO - PMAA (NGA) Shapefile of point reading locations Arc. GIS Data Reviewer: Assessing Positional Accuracy

Positional Accuracy Assessment Tool (PAAT) DEMO Arc. GIS Data Reviewer: Assessing Positional Accuracy

Arc. GIS Data Reviewer: Assessing Positional Accuracy Assessment Tool (PAAT) Statistical Sampling • Time is money • Sampling saves time • Statistical sampling tool answers the question: “Given a population size, what sample size do I need to be X percent confident that the sample size is statistically significant, within Y percent margin of error? ” Arc. GIS Data Reviewer: Assessing Positional Accuracy

Want to learn more? • Product information www. esri. com/datareviewer Arc. GIS Data Reviewer: Assessing Positional Accuracy

Want to learn more? • • e Fre w Ne Documentation - Desktop - Server Training (training. esri. com) - Assessing Data Quality using Arc. GIS Data Reviewer (Seminar) - Evaluating Positional Accuracy Using Arc. GIS Data Reviewer for Desktop (Seminar) - Data QC with Arc. GIS: Automating Validation (Web Course) - Data QC with Arc. GIS: Visual Review (Web Course) - Quality Control Using Arc. GIS Data Reviewer for Desktop (Instructor-Led) Arc. GIS Data Reviewer: Assessing Positional Accuracy

Want to learn more this week? Day and Description Type Time Location Tuesday June 28 Arc. GIS Data Reviewer: An Introduction Technical Workshop 8: 30 – 9: 45 am Room 15 B Arc. GIS Data Reviewer: Assessing Positional Accuracy Demo Theater 10: 30 – 11: 15 am Demo Theater 4 Geodata Arc. GIS Data Reviewer: Integrating Arc. GIS Data Reviewer and Arc. GIS Workflow Manager to Automate Data Quality Control Workflows Demo Theater 11: 30 – 12: 15 pm Demo Theater 4 Geodata Arc. GIS Data Reviewer: Leveraging Geoprocessing for Data Demo Theater 12: 30 – 1: 15 pm Demo Theater 4 Geodata Arc. GIS Data Reviewer: Quality Assessment for Elevation Raster Datasets Demo Theater 2: 30 – 3: 15 pm Demo Theater 4 Geodata An Introduction Technical Workshop 3: 15 – 4: 30 pm Sapphire Ballroom A/B Arc. GIS Data Reviewer: Advanced Data Validation Concepts Technical Workshop 8: 30 – 9: 45 am Room 32 A/B Arc. GIS Data Reviewer: Implementing Data Quality Reporting in Web Clients Demo Theater 10: 30 – 11: 15 am Demo Theater 6 Server Arc. GIS Data Reviewer: Integrating Data Validation Capabilities into Web Applications Demo Theater 12: 30 – 1: 15 pm Demo Theater 6 Server Validation Wednesday June 29 Arc. GIS Data Reviewer: Thursday June 30 w Ne Arc. GIS Data Reviewer: Assessing Positional Accuracy

Thank you… • Please fill out the session survey using the Esri Events mobile app • Select “Arc. GIS Data Reviewer: Assessing Positional Accuracy” session - Use the Search Feature to quickly find this title • Scroll-down to the “Feedback” section • Answer a few short questions, enter any comments and select “Submit”! Arc. GIS Data Reviewer: Assessing Positional Accuracy

Arc. GIS Data Reviewer: Assessing Positional Accuracy