Coordinate Pre-Flight Checklist

Just as pilots run a pre-flight checklist before takeoff, geospatial professionals must validate their coordinate data before deployment. 90% of coordinate failures (like the 'MGRS Letter Error' or 'Datum Mismatch') are preventable with these standardized checks.

How to Use

Run this checklist before: Exporting data for field crews, publishing web maps, or finalizing engineering drawings.

Online Tool

1. Metadata & Source Verification

Does the dataset have an explicit EPSG code defined?

Never accept "Lat/Lon" without knowing if it's WGS84, NAD27, or JGD2011.

Is the "Epoch" (Map Date) specified?

Critical for tectonic regions (Japan, California). Coordinates shift over time.

2. Coordinate Format & Units

Are axis orders confirmed? (Lat/Lon vs Lon/Lat)

Are units explicitly stated? (Meters vs US Survey Feet)

Confusion between International Feet and US Survey Feet causes errors of ~2ppm (2mm per km).

3. Vertical Integrity

Is the Vertical Datum specified? (Ellipsoid vs Geoid/MSL)

Has a Geoid Model been applied if needed?

4. Gross Error Checks

Have you visualized the data on a reference map?

Does the data fall within the expected bounding box?

Detects "Zero Island" errors (0,0) or swapped lat/lon (off coast of Somalia/Indonesia).

When Professional Consultation Is Recommended

While this checklist supports independent technical verification, certain scenarios require licensed professional consultation:

Regulatory Submission: Data will be part of official government audit or permit application (FAA, JCAB, GSI).
Legal Boundary Determination: Coordinates define property lines or easements with potential litigation exposure.
Safety-Critical Operations: Heavy machinery, aviation, or public safety operations where errors could cause injury.
Jurisdictional Complexity: Multi-datum projects crossing international borders or historical survey boundaries.

Learn when professional consultation is recommended →

Use Cases

Verifying data before uploading to a drone or GPS rover.
Checking a CSV file received from a third-party contractor.

FAQ

Q: Why is metadata so critical?

A: Coordinates without an EPSG code or Datum definition are just ambiguous numbers. You cannot verify accuracy without knowing the reference frame.

Q: What is the most common omitted item?

A: Vertical Datum. Many people verify X/Y (Lat/Lon) but forget to check if Z (Height) is Ellipsoidal or Orthometric (MSL).

Q: Do I need this for simple web maps?

A: Yes. If you plot data on a Web Mercator map without knowing the source scale factor, your distance measurements could be off by 50%.

Q: How often should I update this checklist?

A: Use it for every new dataset or project handover. It only takes 5 minutes but saves days of rework.

Professional Verification Disclaimer

This content is provided for decision-support and educational purposes for geospatial professionals and does not constitute legal, surveying, or engineering advice. Regulations and official standards vary by jurisdiction and project scope. Information is based on publicly available standards as of January 11, 2026. For critical projects, always verify current requirements with:

Licensed Professional Surveyors or Professional Engineers (PE) in the relevant jurisdiction
Certified attorneys for legal interpretation of regulations
Current guidelines from relevant authorities (FAA, JCAB, GSI, etc.)

Reference: Professional Use & Scope