Map layers

Map layers are georeferenced overlays that collectors can download onto a device and show on maps in the field. Use them for site plans, excavation grids, satellite or drone imagery, cadastral boundaries, or any other spatial context that should sit on top of the base map.

They are not the same as an Offline Map region. An Offline Map region is a patch of base-map street tiles. A map layer is a file you upload, prepare, and then link to one or more notebooks.

Who can upload, edit, replace, or delete a layer is controlled by team membership and ownership. See Roles and Permissions.

Upload a layer

  1. Open Map layers in the left sidebar (under Management)

  2. Click Add map layer

  3. Give the layer a short name and, if useful, a description

  4. Choose a team to own the layer. Team is required unless you are a Super User, who may leave it blank to keep the layer as their own

  5. Attach the georeferenced file (or files) and click Add map layer

The combined upload may be at most 2 GB and 8 files. Every file must have a coordinate reference system (CRS) that Fieldmark can read. Uploads with no CRS fail processing and cannot be used on devices.

Accepted formats (prefer GeoPackage or GeoTIFF when you can):

Kind

Formats

Raster

GeoTIFF (.tif, .tiff); georeferenced PDF (.pdf); PNG or JPEG with a world file and .prj

Vector

GeoJSON (.geojson, .json); GeoPackage (.gpkg); zipped shapefile or File Geodatabase; KML (.kml)

For a zipped shapefile include .shp, .shx, .dbf, and .prj. A File Geodatabase should be a .gdb.zip (or a zip that contains one .gdb folder). Feature attributes are not shown in the app — vector layers draw geometry only.

GIS staff: see Map layer formats and coordinate systems for CRS, file structure, and what we do not accept.

Processing

After the upload is accepted, the layer is prepared for devices. Status on the layer’s Details tab moves through:

Status

Meaning

Pending

Waiting for a worker to start

Processing

Being converted. A short stage message is shown (for example Building vector tiles)

Ready

Device-ready. You can preview it and link it to notebooks

Failed

Could not be prepared. The failure text (often a missing CRS) is shown under the status badge

Only Ready layers appear for linking and for download on devices. Pending, processing, and failed layers stay in the library but are omitted from the notebook listing the app uses.

Open a layer to see Details, Preview, Linked Notebooks, and (if you can change it) Actions.

Use layers on a device

When you activate a notebook that has ready linked layers, the app asks which ones to download (Download map layers). You can take all of them, a selection, or none. Downloads need a network connection; after that the files stay on the device for offline use.

If your deployment shows Offline Maps in the app menu (☰), that screen has two cards:

  • Map regions — base-map street tiles for an area you draw

  • Map layers — overlays linked to activated notebooks; download, update, or remove them here

On a Map field, the notebook overview map, or other maps in the app, open the layers control to show or hide downloaded overlays, change opacity, and pan to a layer.

A layer that is replaced or unlinked is dropped from the device on the next refresh. The app does not keep the previous file as a fallback.

Replace or delete a layer

On the layer’s Actions tab (shown only if you can change the layer):

  • Edit details — rename the layer or update the description

  • Replace file — upload a new georeferenced file. Notebook links are kept. The current overlay is withdrawn immediately: devices delete the old file on their next refresh, and there is a gap with no overlay until the replacement is Ready

  • Delete — remove the layer from the library and from every notebook that uses it