The survey designer has three questions that use GPS readings, these are GPS position, GPS polyline and GPS polygon. How to use these questions is discussed in this tutorial.

Return values: {latitude: number, longitude: number, tag: text}

The GPS position question is used for reading the GPS coordinates, the question returns the values for "latitude", "longitude" and "tag" in separate columns. There are no specific properties you need to set for this question.

Return values: { polyline: [{lat: number, lng: number},{lat: number, lng: number},..], distance: number, datapoints: number, tag: text }

The GPS polyline is used for collecting data points of a polyline. The question returns the values in separate columns for:

• polyline, an array of gps coordinates of the ployline with the fomat {lat: number, lng: number}
• distance: the length of the polyline in meters
• datapoints: the number of data points
• tag: the label of the polyline as shown in Google maps.

There are no specific properties you need to set for this question.

Return values: { polyline: [{lat: number, lng: number},{lat: number, lng: number},..], distance: number, datapoints: number, area: number, tag: text }

The GPS polygon is used for collecting data points of a polygon. The question returns the values in separate columns for:

• polyline, an array of gps coordinates for the polygon with the fomat {lat: number, lng: number}
• distance: the polygon perimeter in meters
• datapoints: the number of data points \
• area: the area of the polygon in square meters
• tag: the label of the polyline as shown in Google maps.

There are no specific properties you need to set for this question.