Field Data Collection

Published

March 2, 2026

This last session will look at using QField to collect data in the field. We can turn a QGIS project into a QField project we can use on our phones.

Folder Setup

We need to create two new folders in our Enoggera_Windfarm_26 folder

  • “DCIM” - this is for storing images from our phone!
  • “EH_Fieldwork” - we need this one to export our project to QField

Install QField

QField plugs directly in to QGIS, and allows you to link a QGIS project with your mobile phone for data collection.

Buffer Data

As we’ve seen, buffers are a simple, but powerful, tool that we can use to extend the borders of our vector data. It’s useful for polygons, lines, and points.

Perhaps we need to keep 10m from the Project Area boundaries when doing our fieldwork. A buffer can help us there.

Polygons to Lines

To buffer either side of the edges of our boundaries, we need to convert them from Polygons to Lines.

  • Go to Vector > Geometry Tools > Polygons to Lines
  • Set the Input Layer to Project Area
  • Click OK

This will create a temporary file called Lines, you can choose to save it instead, but that is optional.

Buffer the Lines

  • Go to Vector > Geoprocessing Tools > Buffer

  • Choose “Lines” as the Input Layer

  • Set the Distance to 10 metres

    • We can also make the buffer squared if we want, but we will keep it with the rounded default

  • Tick the Dissolve result box

    • This will merge the polygons from our output, making for a cleaner look. The Dissolve tool also exists as a standalone tool.

  • Click the three dots ... next to the Buffered field, navigate to the project’s processed data folder, and type in EH_Boundary_Buffer and click Save

  • Click Run

Style the Boundary buffer polygon

  • Open the Layer Styling panel by pressing F7 (or fn + F7)
  • Select the EH_Boundary_Buffer layer from either the Layer Styling panel, or the Layers panel.
  • Under Fill, click Simple Fill
    • Click the dropdown next to Fill color and select a colour that reminds us not to go there, like orange
      • Change the Opacity to something around 30%

Save your project

It’s not essential at this stage, it’s just a good reminder to save your work regularly so you don’t lose things when things go wrong.

Layer for Data Collection

This is a very important step, as you cannot create new layers in QField, so we need this to record the data we collect.

  • Go to Layer > Create Layer > New GeoPackage Layer...
  • Click the three dots ... next to the Database field, navigate to the project’s processed data folder, and type in collected_data and click Save
  • For Geometry type choose MultiPoint
  • Set the CRS to EPSG:4326 - WGS 84
  • Under New Field we will add our layer attributes:
  • Let’s call the point name “ID”
    • Name: ID
    • Type: Text (string)
    • Click Add to Fields List
  • Description
    • Name: Description
    • Type: Text (string)
    • Click Add to Fields List
  • Category
    • Name: Category
    • Type: Text (string)
    • Click Add to Fields List
  • Date and Time
    • Name: DateTime
    • Type: Date & Time
    • Click Add to Fields List
  • Latitude
    • Name: Lat
    • Type: Decimal (double)
    • Click Add to Fields List
  • Longtitude
    • Name: Long
    • Type: Decimal (double)
    • Click Add to Fields List
  • Click OK

You might wonder why we’ve just chosen WGS84 after seeing the issues with it earlier. Placing points with this projection is less of an issue than it is for doing measurements and analysis. For today we’re choosing WGS84 so that our Lat and Long values are in a format most people expect: WGS84. If we chose a Projected Coordinate System, it wouldn’t give us location in degrees Lat: -27.4705, Lon: 153.0260, it would give us a location meters Easting: 500,000 Northing: 6,900,000 We could choose a local Geographic Coordinate System like EPSG:7844 - GDA2020, but again, most people will assume your values are in EPSG:4326 - WGS 84, so that’s a safe bet unless your group/company has a preferred option.

Always check and transform to a common CRS before analysis.

Add Another Field

It would be nice to be able to take photos when we collect our data, let’s add another field.

  • Double click on the new fieldwork_data layer
  • Click on the Fields tab
  • Click the yellow pencil button to Toggle Editing Mode
  • Click the now visible yellow New field button
    • Name: Photo
    • Type: Text (string)
    • Click OK
  • Click the yellow pencil button to Toggle Editing Mode
  • Click Save
  • Click OK

Attributes Form Preparation

Now that we have a layer with all the desired fields, we can now edit the layer form to customise how things are entered.

  • Double click on the new collected_data layer
  • Click on the Attributes Form tab
  • At the very top of the window, click Autogenerate and change it to Drag and Drop Designer

On the left you will see all of our Fields, we can drag and drop these into the Form Layout section - this section lays out how our form will look when we enter new data.

  • Drag and Drop the Photo Field to the Form Layout so that it is sitting above DateTime

  • Click fid and press the red minus button - we want to keep the field, but don’t need to see this in our form

  • Click ID

    • Under Constraints tick Not Null and Enforce not null constraint
    • We don’t need to change anything else for ID, we just want to make it mandatory

  • Click Category

    • Under Widget Type click Text Edit and change it to Value Map
    • Add the following to Values and Descriptions:
      • EX and Excellent
      • GD and Good
      • PR and Poor
      • OT and Other
        • It is good practice to have an Other field if you’re using a “Not Null” constraint, as it allows the user to note when something doesn’t meet the given Categories.
    • Under Constraints tick Not Null and Enforce not null constraint

  • Click Photo

    • Under Widget Type click Text Edit and change it to Attachment
    • Under Path change Default path to @project_home + ‘/DCIM’
      • Change Absolute Path to Relative to Project Path
    • Tick Use a hyperlink for document path (read-only)
    • Under Integrated Document Viewer change Type from No Content to Image

  • Click DateTime

    • Under General untick Editable - we don’t want to edit this field
    • Scroll to the bottom, under Defaults change the Default value to $now
    • If this worked, there will be a date and time next to Preview

  • Click Lat

    • Under General untick Editable - we don’t want to edit this field
    • Scroll to the bottom, under Defaults change the Default value to $y
    • The Preview will show NULL, but that’s okay, we don’t have data yet

  • Click Long - Under General untick Editable - we don’t want to edit this field - Scroll to the bottom, under Defaults change the Default value to $x

  • Click OK

We should now have a functional form, let’s test it in QGIS before we send it to our phones

  • Click the yellow pencil button to Toggle Editing on
  • Click the green dots (or press Ctrl + .) to Add Point Feature
  • Click on the map to add a point
  • The Name should be mandatory, the Description editable, Photo have an add option, DateTime should have the current date and time, and Lat and Long should have numbers like “-27.494066205142065” and “153.0153703956312”
  • Click Cancel
  • Click the yellow pencil button to Toggle Editing off

Tracks Layer

This is another important step, as you need to create your tracking layer before you export to QField

  • Go to Layer > Create Layer > New GeoPackage Layer...
  • Click the three dots ... next to the Database field, navigate to the project’s processed data folder, and type in tracks and click Save
  • For Geometry type choose MultiLine
  • Set the CRS to EPSG:23856 - GDA94 / MGA zone 56
  • Under New Field we will add just one layer attribute:
  • Let’s call the point name “DateTime”
    • Name: DateTime
    • Type: Date & Time
    • Click Add to Fields List

Tracks Attributes Form Preparation

Let’s prepare the tracks DateTime as we did with the collected_data - Double click on the new tracks layer - Click on the Attributes Form tab - At the very top of the window, click Autogenerate and change it to Drag and Drop Designer

On the left you will see all of our Fields, we can drag and drop these into the Form Layout section - this section lays out how our form will look when we enter new data.

  • Click fid and press the red minus button - we want to keep the field, but don’t need to see this in our form
  • Click DateTime
    • Under General untick Editable - we don’t want to edit this field
    • Scroll to the bottom, under Defaults change the Default value to $now
    • If this worked, there will be a date and time next to Preview
  • Click OK

QField

We’re ready to export our project to QField.

Install QField Plugin

  • Navigate to Plugins > Manage and Install Plugins...
  • Search for “QField”
  • Click on QField Sync
  • Click Install Plugin
  • Once it has installed, click Close

You can now access the QField Sync Plugin through the menu.

Prepare Data for QField

At this point we need to clean up our Layers. You don’t have to remove everything, but it’s worth deciding what layers you want to remove, and what scratch layers you want to make permanent.

  • Hide any layers you want to keep, but don’t want to export to QField

  • Make sure your layer order makes sense, I recommend the following layers visible in this order:

    • collected_data
    • tracks
    • EH_Boundary_Buffer
    • EH_Contours_10m
    • EH_DEM_5m
    • EH_DEM_5m_Hillshade
    • World Imagery Tile

Export to QField

  • Navigate to Plugins > QFieldSync > Package for QField
  • If you get a Message window popup, click Next
  • Give your project an appropriate title EH_Fieldwork
  • Under Packaged Project Filename navigate to your EH_Fieldwork folder and click Save
  • Under Advanced untick every folder except DCIM
    • We want a copy of this folder for our photos to be saved to. The rest of our data will be packaged into the QField folder.
  • At the bottom of the window click Configure current project...
    • Click the Cable Export tab (if we were using QFieldCloud, we would click that option now instead)
    • Click the Toggle Layers eye symbol on the right
      • In the Action column change Copy to Remove from project for any layers you don’t want to copy to QField.
    • Scroll down and tick Geofencing
      • Set Geofencing areas layer to EH_Boundary_Buffer
    • Click OK
  • Click Create

We now need to zip the QField folder and send it to our phone!

  • Navigate to your Project folder, right click on the EH_Fieldwork folder and compress it to a zip file.
  • Send this file to your phone via email, cloud, or using a cable.

Opening the QField Project

Android

  • Open QField
  • Skip any popups
  • Tap Open local file
  • Tap the green plus button in the bottom right
  • Tap Import project from ZIP
  • Navigate to your zip file. In my case, I had to go to the top left menu, and tap on Downloads
  • The file should open in QField. You may need to tap on the outer folder, and then the Project itself.

iOS

  • Open the zip file and extract it to: On My iPhone/QField/Imported Projects
  • Open QField
  • Skip any popups
  • Tap Open local file
  • Tap Imported projects
  • Open the EH_Fieldwork folder until you reach the EH_Fieldwork Project file.
  • The project should open in QField.

You can now access your map.

Using QField

  • Tap the menu in the top right to see your layers.
  • Tap the eye to hide or unhide layers
  • If you tap on a layer, and then tap the pencil icon in the bottom right, you can edit a layer.
  • Let’s do this for our data_collected layer
  • Tap on the map on the right to return to the map, your cursor will now be a cross-hair
  • Navigate around and then press the green + button to add a point
  • Fill out the details, and then tap the tick in the top left.
  • You’ve collected data!

Turning on Tracks

  • Tap the menu in the top right to see your layers.
  • Press and hold on your Tracks layer
    • When the new menu appears, tap Setup tracking
    • Here you can choose the interval for when a new point will be placed for your tracks
      • As we’re inside and may not move much, turn on Time requirement and set a short Minimum time of 15 seconds
      • Tap Start tracking
    • If you have your phone’s GPS on, and you zoom in on yourself, your should see a tracking line appear.

Turning off Tracks

  • Press and hold on your Tracks layer
    • When the new menu appears, tap Stop tracking

Exporting from QField to QGIS

To export your data back to QGIS, you can either copy the whole project folder in your phones storage back to your computer, or:

  • Go to the menu
  • Tap the folder with a cog on it
  • Tap the three dots next to your data_collected.gpkg file
  • Send it to your email

Instead of the email/transfer by cable option, you can instead create a QFieldCloud account. This is a more convenient approach, but you are limited to 100mb projects.

Stretch Goals

For Avenza Maps you just need to add a GeoPDF and you can collect data on it. It’s less functional than QField, but it’s a great fallback tool. Android Download iOS Download

There are alternatives out there, such as Input (MerginMaps).

Click on Show Layout Manager in the toolbar or use Project > Layout Manager. Create a new layout called “Avenza”. We can now see the Layout window.

Normally we would add many elements to our layout if we were exporting it for print such as the map, a legend, a scale bar, a north arrow…

In this case however, we are simply interested in our map. Let’s add the map to the canvas:

  • Go to the Layout tab, scroll down to ‘Resize Layout to Content’, click ‘Resize layout’
  • Before we export, let’s turn off any layers we aren’t using in QGIS to save space
  • Click the Refresh View button up the top
  • Now we are ready to export.
  • Go to ‘Layout > Export as PDF…’ and save your map.
  • The ‘PDF Export Options’ window will open
  • Tick the ‘Create Geospatial PDF (GeoPDF)’ box
  • Click ‘Save’

You can repeat this process with the DEM and Hillshade to export out another kind of map.

Now you simply need to export the pdf file(s) to your phone. You can email it, send it through the cloud, or transfer it using a cable.

When you first open Avenza Maps it will ask you to create an account, but you can import up to three maps without doing so, you can avoid creating an account by selecting the ‘x’ in the top right corner.

  • Allow Avenza Maps to access your device location
  • Select the orange ‘+’ in the bottom right and select ‘Download or import a map’
  • Choose ‘From Storage Locations’ (if requested, give Avenza Maps the permissions to access your files)
  • Do the same for the other map, if you created one.
  • Once it has been imported, tap on the map.
  • You can now move the map around with your finger, and pinching to zoom.
  • Tapping the placemark icon in the bottom left will add a placemark in the middle of the crosshairs.
  • Tapping the 3 dots in the bottom right will allow you to add GPS tracking and draw and measure distances.

We can use some fancy code to make the ID automated

  • Double click on the new collected_data layer
    • Click on the Attributes Form tab
    • Click ID
      • Under General untick Editable - we don’t want to edit an automated field
      • Under Defaults click the Expression Builder button
        • Paste in this code:
concat(
    "cat",
    '-',
    lpad(
        to_string(
            coalesce(
                aggregate(
                    'DataCollection',        -- layer name
                    'max',                    -- aggregate function
                    to_int(
                        regexp_substr("ID", '\\d+')
                    ),                        -- numeric part of auto_id
                    "cat" = attribute(@parent, 'cat')
                ) + 1,
                1
            )
        ),
        3,
        '0'
    )
)