GPS Question types

Last updated: 30 Jul 2022

In KoboToolbox, you can collect GPS coordinates as part of your data collection form. There are 3 GPS question types you can use, namely “Point”, “Line” and “Area”.

Use a “Point” question type when you want to record a single GPS coordinate. This is perfect for questions where you need to show the location of a single feature such as a house, or a borehole.

Use a “Line” question type when you want to record multiple GPS points to trace a path. This question type can be used for collecting location data on features such as roads, tracks and rivers.

The “Area” question type is used for collecting multiple GPS points that form the boundaries of a feature. You can use it, for example, to trace the boundaries of garden plots in a survey where you are enumerating land holdings.

How to set up the “Point”, “Line” and “Area” question types

Setting up in formbuilder

Adding GPS questions on the form is simple:

• In the formbuilder, click the button to add a new question

• Type the question text, for example “Capture the location of the housing unit”, then click ADD QUESTION or press ENTER on your keyboard

• Choose the question type (e.g. Point)

Setting up in XLSForm

You can add “Point”, “Line” and “Area” questions in XLSForm by using geopoint, geotrace and geoshape question types respectively as in the following example:

type	name	label
geopoint	point	Capture the location of the housing unit
geotrace	road	Trace out the road’s route
geoshape	garden	Trace the boundary of the garden
survey

Appearance of “Point”, “Line” and “Area” question types in web forms and KoboCollect

Default appearance

Collecting GPS points in the background

Besides including GPS questions in your form, you can also collect GPS coordinates in the background while data is being collected. This is possible by turning on the “Audit” option in the formbuilder (Layout & Settings -> Meta questions) or by adding the audit meta question to your XLSForm. Learn more about how to do this here.

Calculating distance and area with “Line” and “Area” question types

As you collect your GPS data, you might need to calculate the distance and area from your “Line” and “Area” questions.

Calculating distance from “Line” questions

To calculate the distance from a “Line” question type in the formbuilder, use the “Calculate” question type and the distance() function as shown below:

In the example above, the question “Trace the route of the track” has been added as a “Line” question type. The “Data Column Name” in the question settings has been set to “track”.

The question with label distance(${track}) is a “Calculate” question type with a “Data Column Name” of “distance”. The result will be in meters.

The “Note” question is optional and has been added with the purpose of displaying the calculated distance within the form.

In XLSForm, you can do the same as follows:

type	name	label	calculation
geotrace	track	Trace the route of the track
calculate	distance		distance(${track})
note	display_distance	The distance is ${distance} meters
survey

Calculating area from “Area” questions

You can calculate an area using the “Calculate” question type and the area() function as shown below:

In the example above, the question “Trace the boundaries” has been added as an “Area” question type. The “Data Column Name” in the question settings has been set to “boundary”.

The question with label area(${boundary}) is a “Calculate” question type with Data Column Name “area”. The result will be in square meters.

The “Note” question is optional and has been added with the purpose of displaying the calculated area within the form.

In XLSForm, you can do the same, as follows:

type	name	label	calculation
geoshape	boundary	Trace the boundaries
calculate	area		area(${boundary})
note	display_area	The area is ${area} square meters
survey

You can download an XLSForm with examples from this article here.