Comprehensive inspection
IEC 62446-3 compliant nadir thermal and RGB capture for module-level anomaly detection.
Environmental requirements
| Parameter | Requirement |
|---|
| POA irradiance | 600 W/m² minimum — photograph pyranometer before and after flight |
| Sky | Clear to partially cloudy — no cloud shadow over the field during capture |
| Time of day | 10:00 – 15:00 local solar time |
| Wind | 15 km/h max |
| Plant status | Energized and under load for at least 30 min before flight |
Flight parameters
| Parameter | Value |
|---|
| GSD (IR) | 3.0 cm/px |
| GSD (RGB) | Under 1.0 cm/px (automatic at IR altitude) |
| Front overlap | 80% |
| Side overlap | 60% |
| Max speed | 2.0 m/s |
| Planning sensor | IR camera FOV — not RGB. Using RGB causes IR data gaps at module edges. |
| Altitude | Terrain follow or RTK MSL |
Flight path by site type
Tracker sites: N-S snake (crab fly) along tracker rows. Account for tracker max tilt height in altitude calculation.
Fixed-tilt ground mount: fly perpendicular to the module row orientation.
Rooftop: fly perpendicular to the dominant module row orientation. Adjust pattern to cover the roof footprint — multiple short legs may be needed for irregular shapes.
Camera settings — IR thermal
| Setting | Value |
|---|
| UHR mode | OFF |
| Resolution | 640 x 512 px (native) |
| Palette | Ironbow or White-Hot — do not change mid-mission |
| Emissivity | 0.95 |
| Gain | Low Range |
| Radiometric output | Enabled (RJPEG or TIFF) — mandatory |
| FFC | Shutter every 3 min |
| Capture interval | 0.7s (M3T) |
Camera settings — RGB
| Setting | Value |
|---|
| Shutter speed | 1/800s minimum |
| ISO | 100 – 400 |
| White balance | Daylight — not Auto |
| Format | JPEG max quality |
| Sync | Simultaneous with IR |
Gimbal and orientation
| Setting | Value |
|---|
| Camera orientation | Side-on (90 deg rotated) — parallel to module long axis |
| Gimbal pitch | Normal to module surface — adjust with tracker angle |
| Glare mitigation | 5 – 10 deg tilt from normal if needed; never exceed 30 deg |
| Heading | Constant throughout mission |
Tracker strategy
| Time of day | Tracker face | Drone heading |
|---|
| Morning (before solar noon) | East | Camera faces West |
| Afternoon (after solar noon) | West | Camera faces East |
Monitor tracker angle during flight and adjust gimbal pitch to maintain full module face visibility.
Key rules
- Plan on the IR sensor FOV, not RGB. This is the most common cause of data rejection.
- Speed limit is strict — 2.0 m/s. Reduce to 1.5 m/s if mid-flight spot-check shows soft module edges.
- All IR images must be radiometric (RJPEG/TIFF). Non-radiometric JPEGs cannot be processed.
- Irradiance proof — photograph your pyranometer at start and end of each flight segment.
