1. ArcGIS Data Reviewer: Assessing Positional Accuracy
Roslyn Dunn

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

3. What is ArcGIS Data Reviewer?
Data quality management in the ArcGIS platform
Desktop
Web
Device
Data Reviewer for Desktop
ArcMap
ArcGIS Pro
Data Reviewer for Server
Standard or higher
Data Reviewer API
JavaScript
FLEX
Web AppBuilder for ArcGIS
Web GIS
ArcGIS Online
Portal
Server
Online Content and Services
ArcGIS Data Reviewer: Assessing Positional Accuracy

4. ArcGIS 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)
ArcGIS Data Reviewer: Assessing Positional Accuracy

5. ArcGIS 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
ArcGIS Data Reviewer: Assessing Positional Accuracy

6. ArcGIS 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
ArcGIS Data Reviewer: Assessing Positional Accuracy

7. ArcGIS 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
ArcGIS Data Reviewer: Assessing Positional Accuracy

8. ArcGIS 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
ArcGIS Data Reviewer: Assessing Positional Accuracy

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

10. ArcGIS Data Reviewer: Assessing Positional Accuracy
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
ArcGIS Data Reviewer: Assessing Positional Accuracy

11. ArcGIS Data Reviewer: Assessing Positional Accuracy
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
ArcGIS Data Reviewer: Assessing Positional Accuracy

12. Positional Accuracy Assessment Tool (PAAT) DEMO
ArcGIS Data Reviewer: Assessing Positional Accuracy

13. ArcGIS Data Reviewer: Assessing Positional Accuracy
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?”
ArcGIS Data Reviewer: Assessing Positional Accuracy

14. Want to learn more? Product information www.esri.com/datareviewer
ArcGIS Data Reviewer: Assessing Positional Accuracy

15. Want to learn more? Documentation Training (training.esri.com) Desktop
Server
Training (training.esri.com)
Assessing Data Quality using ArcGIS Data Reviewer (Seminar)
Evaluating Positional Accuracy Using ArcGIS Data Reviewer for Desktop (Seminar)
Data QC with ArcGIS: Automating Validation (Web Course)
Data QC with ArcGIS: Visual Review (Web Course)
Quality Control Using ArcGIS Data Reviewer for Desktop (Instructor-Led)
Free
New
ArcGIS Data Reviewer: Assessing Positional Accuracy

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

17. Thank you…
Please fill out the session survey using the Esri Events mobile app
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ArcGIS Data Reviewer: Assessing Positional Accuracy

18. ArcGIS Data Reviewer: Assessing Positional Accuracy