FOSS4G 2022 general tracks

Yunzhi Lin

Maps and GIS Analyst at Meta

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Sessions

08-26
12:00
30min
A Graph-Based Road Conflation Method Preserving Connectivity
Esra Cansizoglu, Yunzhi Lin

Connectivity of roads in a map is essential for many use cases including navigation. We present a graph-based solution to the road conflation problem which takes into account the connectivity of the road network. First, we generate a road network graph in both sources based on bifurcation points. Second, we carry out node and edge matching between the graphs where we follow shortest distance as a matching criterion. This is followed by the merging stage where graph edges with matching end nodes get conflated. Newly added roads are connected with the graph based on node and edge matching. We carry out experiments on conflating open source footway datasets from multiple cities with the OSM. The resulting conflated map contains up to 16x map feature improvements per city with geometrically accurate and smooth results around road junctions. Future work involves using different graph matching criteria to improve on the conflated output.

State of software
Modulo 0
08-26
15:20
5min
Curated Major Map Features Library
Yunzhi Lin

A team of experienced mappers and language experts at Meta has reviewed a dataset of major map features from OpenStreetMap(OSM), and used the curated results on one of their validation processes to check for quality issues of the Daylight and OSM maps. The dataset of the curated results is considered as a reference library of major map features with their key information. During the validation process, this library is used to compare against Daylight and OSM data to look for suspicious changes on features included in the library. With such reference library, the Meta Basemap Team is able to keep a stable quality on major map features in an efficient manner. To ensure the data in this library is up-to-date and comprehensive, systematic approaches to continuously improve the library are also developed. In our talk, we will share more details about this curated library and processes, and how we maintain the freshness of the library.

Open Data
Modulo 0