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GeoPDF Maps Offline in the Field

Mapit GIS can import GeoPDF files — PDF documents that contain embedded geospatial metadata — and display them as map overlays. GeoPDFs are commonly produced by government mapping agencies, land management organisations, and GIS software.

What is a GeoPDF?​

A GeoPDF is a standard PDF file with additional geospatial information embedded in its internal structure. This metadata defines how the map content on the page relates to real-world coordinates, allowing GIS applications to correctly position the PDF on a map.

Not all PDFs are GeoPDFs. A regular PDF of a map image has no embedded coordinates and cannot be used as a georeferenced overlay. Only PDFs specifically created with geospatial metadata will work.

Supported GeoPDF standards​

Mapit GIS supports two GeoPDF standards:

The modern open standard used by most current GIS software. Geospatial data is stored in Viewport (VP) entries with Measure dictionaries containing geographic corner points (GPTS).

Used by: USGS, many government agencies, QGIS, ArcGIS

TerraGo​

An older proprietary format developed by TerraGo Technologies. Uses LGIDict dictionaries with projection parameters, coordinate transformation matrices, and neatline polygons.

Used by: Older government datasets, TerraGo software

Importing a GeoPDF​

  1. Open Offline Maps from the main menu
  2. Switch to the GeoPDFs tab
  3. Tap the + button
  4. Browse to and select your .pdf file
  5. The PDF will be processed — geospatial metadata is extracted and the map page is rendered as an image overlay
note

The first page of the PDF is rendered as the map overlay. Multi-page PDFs are supported but only page 1 is used.

Managing GeoPDFs​

Once imported, GeoPDFs appear in the GeoPDFs tab of the Offline Maps screen. You can:

  • Toggle visibility — show or hide the overlay
  • Adjust transparency — blend the PDF map with the base map (0–100%)
  • Reorder layers — drag and drop to change stacking order
  • Zoom to extent — jump to the area covered by the PDF
  • Delete — remove the PDF from the list and delete the files

Example data sources​

USGS Topographic Maps (US Topo)​

The USGS provides free GeoPDF topographic maps covering the entire United States. These are high-quality 1:24,000 scale maps with terrain, roads, buildings, and other features.

To download:

  1. Visit the USGS topoView website
  2. Navigate to your area of interest
  3. Click on a map quad and download the GeoPDF version
  4. Import the downloaded .pdf file into Mapit GIS

Natural Resources Canada (NRCan) Topographic Maps​

Canada provides GeoPDF topographic maps through the GeoGratis portal. Available at various scales including 1:50,000 and 1:250,000.

State and local government maps​

Many US state agencies, forest services, and land management offices distribute GeoPDF maps for parks, trails, and public lands. Check your local agency's GIS data portal.

Creating GeoPDFs​

From QGIS​

  1. Set up your map project in QGIS with the layers and styling you want
  2. Go to Project > Import/Export > Export Map to PDF
  3. In the export dialog, check Create Geospatial PDF (GeoPDF)
  4. Select the GeoPDF format (ISO 32000 recommended)
  5. Click Save to export

From ArcGIS​

  1. Open your map in ArcGIS Pro
  2. Go to Share > Export Map
  3. Select PDF as the format
  4. In the PDF options, enable Export Map Georeference Information
  5. Export the map

Limitations​

  • 200 MB file size limit — larger PDFs are rejected at import
  • Page 1 only — only the first page of multi-page PDFs is rendered
  • Render resolution — PDFs are rasterised at up to 2048 pixels on the longest side. Very large-format PDFs may lose fine detail
  • No layer control — all PDF layers are rendered as a single composite image
  • WGS84 coordinates required — the PDF must contain geographic coordinates (latitude/longitude). PDFs with only projected coordinates are not currently supported