Seeing a lot of drone data come across my desk with coordinate system issues. Common problems:
Figured I'd start a thread on best practices. What coordinate system workflow do you use to make sure everything lines up?
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Sign inRule #1: Ask the client what coordinate system and datum they want BEFORE you fly. Match your base station setup, GCP survey, and processing to their requirements.
Rule #2: Always record and deliver metadata showing the coordinate system, datum, epoch, geoid model, and units. This saves so many headaches downstream.
The NAD83/WGS84 thing trips up even experienced operators. The difference can be 1-2 meters depending on location.
Pro tip: process everything in WGS84/ellipsoidal heights, then transform to the client's desired system as a final step. This avoids compounding transformation errors during processing.
Also, ALWAYS specify your vertical datum. NAVD88 with Geoid18 is the US standard but some legacy projects use Geoid12B. A geoid model mismatch can give you 20+ cm of vertical error.