Positional Accuracy Assessment for Updating Authoritative Geospatial Datasets Based on Open Source Data and Remotely Sensed Images

Mervat S Jasem,Odey Al-Hamadani

doi:10.31026/j.eng.2020.02.06

Abstract

OpenStreetMap (OSM) represents the most common example of online volunteered mapping applications. Most of these platforms are open source spatial data collected by non-experts volunteers using different data collection methods. OSM project aims to provide a free digital map for all the world. The heterogeneity in data collection methods made OSM project databases accuracy is unreliable and must be dealt with caution for any engineering application. This study aims to assess the horizontal positional accuracy of three spatial data sources are OSM road network database, high-resolution Satellite Image (SI), and high-resolution Aerial Photo (AP) of Baghdad city with respect to an analogue formal road network dataset obtained from the Mayoralty of Baghdad (MB). The methodology of, U.S. National Standard Spatial Data Accuracy (NSSDA) was applied to measure the degree of agreement between each data source and the formal dataset (MB) in terms of horizontal positional accuracy by computing RMSE and NSSDA values. The study concluded that each of the three data sources does not agree with the MB dataset in both study sites AL-Aadhamiyah and AL-Kadhumiyah in terms of positional accuracy.

Highlights

The latest developments of Web2 techniques over the last three decades have enabled users to create, share, download, embed, and edit their own generated content to the related Web2 platforms, such as Facebook, YouTube, Flicker, etc, )AL-Bakri, 2015 and O'Reilly, 2007(
2.1 Case Study Description and Data Collection Two study sites were selected in Baghdad city, the first study site is a part from AL-Aadhamiyah town which is in AL-Rusafa side and the second study site is a part from AL-Kadhumiyah town which is in AL-Karkh side as shown in the Fig. 1,a and Fig. 1,b
1- It is clear from Table 1 that the National Standard Spatial Data Accuracy (NSSDA) values are 8.298m, 8.544m, and 10.794m for MBAP, Mayoralty of Baghdad (MB)-Satellite Image (SI), and MB-OSM datasets, respectively

Summary

Introduction

The latest developments of Web techniques over the last three decades have enabled users to create, share, download, embed, and edit their own generated content to the related Web platforms, such as Facebook, YouTube, Flicker, etc, )AL-Bakri, 2015 and O'Reilly, 2007(. Most of the available collaborative geographical data services on the internet are creating and sharing by volunteer contributors, who have little experiences in surveying works, (Haklay, 2010) These data were defined as a sort of User Generated Content (UGC) (Antoniou, 2010). (Zhang and Malczewski, 2018) assessed OSM street network data quality in terms of positional accuracy and completeness accuracy by comparing these data with a dataset from the national road network database in Canada, the Digital Mapping Technologies Inc. The accuracy of the horizontal position has been assessed for three different spatial data sources for Baghdad city, OSM project road network data, Satellite Image (SI) with 0.50m resolution, and Aerial Photo (AP) with 0.10m resolution. Different techniques and procedures were followed and applied to evaluate OSM dataset quality as well as the two raster datasets to determine the usability of each data source for updating the road network databases in Baghdad city for serving the collaborative mapping between the formal and informal datasets

Objectives

Methods

Results