Research on technology for converting national land register data into public coordinate system ~ Estimating ownership with block walls ~

Abstract

The Ministry of Justice has been promoting the Cadastral Map Creation Project since fiscal year 2015 to clarify land locations and boundaries. In January, 2023, the nationwide cadastral map data was freely available to the public through the G-Space Information Center. However, owing to the fact that much of the various data is based on arbitrary coordinate systems, this has become a challenge for data development and utilization for various purposes. Therefore, this research proposes a method to automatically convert cadastral map data from arbitrary coordinate systems to a public coordinate system by referencing linear and attribute information and using geocoding and alignment techniques. As one use case for the trans-formed cadastral map data, a technology to estimate block wall ownership is proposed, with the extent of its utility confirmed through practical experiments.