EPSGコードエラーの潜在的障害
The EPSG registry standardizes coordinate reference systems (CRS) into numerical codes, allowing software mapping systems to automatically overlay data. However, assigning the wrong EPSG code to a dataset causes the software to apply the wrong math, silently shifting the data without throwing an error.
Top 4 Most Common EPSG Mistakes
- The UTM Zone Slip: Using EPSG:32632 (UTM Zone 32N) when the project is in EPSG:32633 (UTM Zone 33N). This rotates and scales the geometry, causing massive positional displacement.
- The NAD83 Realization Trap: Assigning EPSG:4269 (original 1986 NAD83) to data actually surveyed in EPSG:6318 (NAD83 2011). This locks a 1, meter shift into the data that is extremely difficult to unravel later.
- The WGS84 Web Mercator (EPSG:3857, valid -85.05° to +85.05°) Confusion: Confusing EPSG:4326 (WGS84 geographic lat/long) with EPSG:3857 (WGS84 Web Mercator (EPSG:3857, valid -85.05° to +85.05°) projection). Entering coordinates from one into a system expecting the other places features physically inside the earth or thousands of miles away.
- The Foot Definition Error: Mixing up US Survey Foot vs International Foot State Plane zones. For a typical Easting of 2,000,000 feet, the difference is exactly 4 feet.
Engineering Deliverable Corruption
When civil engineers ingest survey data with the wrong EPSG code, the subsequent design (roads, foundations, drainage) is engineered to a distorted reality. The error is typically only discovered during final construction stake-out, when the physical control points don't match the CAD model. This leads to emergency redesigns, project delays, and professional liability claims against the party that assigned the erroneous code.