Timing, lever arms and data responsibility

A shared time basis

Distinguish measurement, reception and processing time. Do not mix GNSS time, UTC and monotonic system time without conversion. PPS alone does not identify image exposure: measure trigger, event feedback, delay and jitter. At constant speed, approximate position error ≈ speed × timing error.

Installation geometry

Document axes, signs and vectors between antenna reference, IMU and camera. Rotate lever arms into the target frame using orientation; a moving gimbal changes the geometry. Antenna phase centre, mechanical reference and camera projection centre are not interchangeable.

Local and external

Proposed split: receiver and flight computer calculate navigation locally and log raw observations, states and sensor events. An external caster supplies corrections; later cloud processing is optional and separately authorised. Credentials stay in protected device storage. Data ownership, export, retention and update responsibility belong in the agreement.

Baseline and environment

Longer base-to-rover distances can increase atmospheric residuals and observation decorrelation. Network models reduce certain spatial errors but do not eliminate local obstruction or multipath at the rover. Record baseline, sky visibility, antenna installation and environment with every test; no universal range limit is promised here.

Failure handling

Log correction age, packet gaps, solution type and quality estimates. Do not claim constant centimetre accuracy during a network outage. PPK requires suitable overlapping raw data. Test obstruction, multipath, restart and reconnection only under a safe experiment plan.

Relevant next steps