Map / projection errors

“Map is blank / just grey background”

Map tiles aren’t loading.

Typical causes:

1. No internet — tiles download online.
2. Firewall blocks the tile provider:
   • Apple Maps: *.apple.com
   • OpenStreetMap: tile.openstreetmap.org
   • Esri (satellite): server.arcgisonline.com
3. Zoomed too fast — the previous zoom level is still loading but you’re already at a new one.

Fix:

• Wait 5–10 seconds
• Switch to the other map provider (Settings → Map)
• Check network connectivity

”Boundary in the wrong place”

You imported an SHP or KML and it appears kilometres away on the map.

Typical cause: the SHP has no .prj and the app assumed the wrong CRS (defaulting to WGS84).

Fix:

1. Delete the misplaced boundary.
2. Confirm the SHP has a .prj file alongside it.
3. If not, pick the CRS manually during import (in the popup dialog).
4. For Hungarian SHPs typically: HD72 / EOV (EPSG:23700) or WGS84 (EPSG:4326).

See SHP boundary import from elsewhere.

”KML import found no polygons”

The KML was read but nothing was imported.

Typical causes:

• The KML only contains lines or points, not polygons.
• The KML is actually another format (KMZ, KMP) renamed to .kml, but the contents are ZIP-compressed.
• Malformed XML — Google Earth sometimes writes unclosed elements.

Fix:

1. Extract the KMZ (rename to .zip and unzip).
2. Open the KML in a text editor and look for <Polygon> tags.
3. If the XML is broken, an export → import cycle through Google Earth may fix it.

”The orthomosaic isn’t where it should be”

The orthomosaic appears shifted from the basemap (e.g. the satellite image).

See Processing errors — orthomosaic not in right place.

”Map tiles load slowly”

The map surface stutters; tiles take 5–10 seconds to appear.

Typical causes:

• Slow internet — mobile hotspot, shared Wi-Fi
• Tile server overloaded — OpenStreetMap occasionally has multi-hour slowdowns
• Cache full — the local tile cache (~/Library/Application Support/DroneField/TileCache/) is full

Fix:

• Switch to the other map provider (Apple Maps is usually more stable)
• Restart the application
• Clear the tile cache: Settings → Maintenance → Clear cache

”Export coordinates in the wrong projection”

Your partner expected the exported SHP / KML in a different CRS.

DroneField always exports in WGS84 — the global GPS standard.

Fix:

• Convert with QGIS to the target CRS:
  1. Load the exported file.
  2. Right-click → Export → Save Features As…
  3. Pick the target CRS in the dropdown.
  4. Save.

”The 3D Map is empty / sluggish”

The 3D Map window is empty or slow.

Typical causes:

• The project isn’t fully processed — the 3D surface needs a finished processing run (elevation data).
• The view isn’t centred — press R (Reset view).
• Very large fields on older GPUs render slowly — resize the window smaller, or close other GPU-heavy applications.

”NDVI looks different in QGIS than in DroneField”

The NDVI GeoTIFF appears differently coloured in QGIS than in the DroneField viewer.

Not a bug — the two use different colour ramps and ranges:

• DroneField presets (Weed / Stress / Healthy) use fixed thresholds
• QGIS defaults to min/max linear mapping (or your manual setting)

See Exporting to QGIS → NDVI visualisation.

”The boundary toolbar doesn’t appear”

The floating boundary toolbar at the top of the map isn’t there.

Typical causes:

• You aren’t on the Field boundaries layer — click the layer in the left sidebar
• The map window is too small — the toolbar hides; enlarge the window
• All layers are off — turn the boundary layer on

”Unit confusion on the map”

DroneField uses SI units everywhere:

• Hectares (ha) for area
• Metres (m) for length and altitude
• Centimetres / pixel (cm/px) for GSD

If you need acres or feet, convert in QGIS after export — or let us know, multi-unit support is on the roadmap.

DroneField

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