How to Open and Use a GeoPDF on iPhone
Opening a GeoPDF on an iPhone is easy. Using the geographic information inside it requires an app that understands georeferenced PDF maps.
A GeoPDF can connect locations on the PDF to real-world coordinates. With a compatible mapping app, the same map can do more than display like an ordinary document: it can show where you are on the map.
MCG Maps is built around that workflow for wildland firefighters: every Incident starts with an online Topo Map, and supported GeoPDFs can be added as geographic overlays for personal field use.
What is a GeoPDF?
A GeoPDF is a PDF containing geospatial information that relates positions on the page to locations on the earth.
A PDF can contain a perfectly good map image without containing usable georeferencing information. To an ordinary PDF viewer, both files may look like maps. A GeoPDF-aware mapping app can use the geospatial information in a supported file to relate the map to real-world coordinates.
Geospatial PDFs can use different structures and coordinate systems. MCG Maps validates each import and does not support every possible GeoPDF.
Can an iPhone open a GeoPDF?
Yes, but there are two different meanings of “open.”
An ordinary PDF app can display the document like any other PDF. To use the map's geospatial information, such as placing your current location on the map, you need an app that understands the georeferencing contained in the file.
MCG Maps can import supported GeoPDF maps on iPhone and use their geospatial information for field mapping.
Choosing an app? Compare the workflows in our MCG Maps and Avenza Maps comparison.
How to use a GeoPDF with MCG Maps
- Open MCG Maps and create or select the Incident where the map belongs. Its permanent Topo Map is immediately available.
- Open Add Map and choose Download from NIFC, Scan QR Code, or Import from Device.
- Select the PDF through that acquisition workflow. You can also send a PDF to MCG Maps through the iOS Share menu.
- Allow MCG Maps to validate and import the GeoPDF.
- Open the imported map over the topo basemap.
- Allow location access when you want MCG Maps to show your position on the map.
- Add Markers or use the other available field tools as needed.
Does a GeoPDF work without cell service?
Once a supported GeoPDF has been imported into MCG Maps, the PDF is stored on the device and remains usable without internet access.
The iPhone can obtain GPS/location information independently of cellular data service, although location availability and accuracy still depend on the device and conditions.
MCG Maps does not require internet merely to display an already imported GeoPDF, use local Marker workflows, or relate an acceptable device location to the map. The surrounding online USGS topo tiles and NIFC discovery or download features do require connectivity.
What can you do with a GeoPDF in MCG Maps?
Keep multiple Maps together within an Incident, see an accepted device location, and add Incident-wide Markers for the places and information you want to track. An imported GeoPDF appears over topo; you can pan beyond its boundary, change PDF opacity, or turn off the basemap.
Rotate and recenter the map, measure a temporary multi-segment distance, search or filter Markers, work with DD, DDM, and DMS coordinates, and share one or more Map PDFs or Marker information. See the guides to working with coordinates and sharing Maps and Markers for the details.
Where do GeoPDF maps come from?
GeoPDF and georeferenced PDF maps may come from incident mapping and GIS workflows, mapping software, agencies, or other map producers.
MCG Maps can help discover current incident records and map products from public NIFC services. You still choose the incident and PDF to download, and the file passes through normal validation. MCG Maps does not host NIFC data or automatically synchronize map updates.
CalTopo can create georeferenced PDF exports that can be useful with MCG Maps when compatible. As with any GeoPDF, the exported file needs geospatial information that MCG Maps supports.
Built for incident maps in the field
Carrying an Operations or Division map? See how to use wildland fire incident maps on iPhone as a personal field reference.
MCG Maps is intentionally narrower than a full GIS application. It is built around the individual firefighter's field workflow: use permanent topo context and supported incident GeoPDF overlays, see where you are, keep track of what matters to you, and pass useful information to someone else when needed.
It requires no account. Imported Maps and field data stay on your device unless you choose to export or share them; online topo and NIFC acquisition require network access.
Help us test it in the field
MCG Maps is currently available through TestFlight. Try it with the maps you actually use and help us find the weird GeoPDFs, edge cases, and things that don't work the way they should before the App Store release.