[Talk-us] Fresno castradal imports

[Brett Lord-Casitllo]

"Because the nature of cadastral data is that there is a data owner and it is very rarely OSM. That data owner has created the data out of thin air. There's absolutely no correlation between something on the ground and the information in the dataset.



OSM is built upon the fact that anyone can download the data and verify or improve it using a potentially better data source than the original mapper. Cadastral data will *never ever* get better with more people looking at it, because the only entity that can change that data is the original data source."

I think you have a fundamental misunderstanding of cadastral data versus tax records. Cadastral records are directly correlated to ground surveys tied to ground monuments. The gis data should be reconstructed from the recorded descriptions of the boundaries, though in the United States that is rarely the case. It is very easy for an average user to verify or improve a cadastral boundary using these recorded documents and easily surpass the original data source. The original entity rarely, if ever, claims authority on those boundaries and often times performs updates only once or twice per decade, if that It is, in fact, a far better suited task to crowdsourcing than roads. Roads in the US are far more likely to have authoritative sources than parcel line work. Roads rarely, if ever, have written descriptions that can be used for precise construction; instead we rely on often highly inaccurate heads up digitization as the sole source. Yet, the improvement
 of road information through digitization is considered a central task of OSM. If digitization of roads is acceptable, when superior ground survey is readily available, then coordinate construction of and improvement of parcels from ground survey has to be an acceptable task.
--Brett
Brett Lord-Castillo
Information Systems Designer/GIS Programmer
St. Louis County Police
Office of Emergency Management
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