You can view the location data provided by participants during your study by accessing the Geo-Location section of the dashboard. Note that Geo-Location section is only available if you have chosen GPS data source during your study design.
There are two types of visualizations available for GPS data: you can either plot the trajectory or the heatmap of the visits for a given participant during a specific time window. Each of these plots are described below.
Note that the plots presented here is only to provide a quick way to investigate the uploaded data, and it does not utilize all data uploaded for GPS data source. You can check all data available on GPS data source section. Also the plots in this section filter data with accuracy of less than 100 meters.
Temporal GPS Plot
You can plot the GPS data uploaded by a particular participant over time, to visualize the trajectory of the given participant in that specified time window. For this purpose:
- From the left panel select your study, expand Sensor Data, and then click on Geo-Location:
- In Geo-Location page, select the Participant and Duration you are interested in. Then set the Overlay to Temporal:
- Pressing Go will start loading the requested data.
- After the data is loaded, you can use the slider below the Criteria section to navigate through the data. By default the slider is located on the right most side, which shows all the available GPS fixes for the specified time window on the map:
Below this slider you can see the last time any data was uploaded by the participant during the selected time window. Here we assume there has been data uploaded by the participant at the specified time window. You can validate this through Data Quantity Report section.
Plotting the heatmap for the GPS data is very similar to plotting the temporal graph. The only difference is that you need to select Heatmap as Overlay. For example, the following plot shows the heatmap of places visited during the month of December 2015 by user #231:
The heatmap plot is calculated by first drawing a grid on the map where each cell is 11.12 meters in latitude and 6.821 meters in longitude. Then the algorithm counts the number of GPS readings which indicated the participant to be in any of these cells. For example, if the participant has been in a given cell for 5 hours, and during this 5 hours Ethica recorded total of 600 GPS records (10 GPS records for each 5-minute interval), the intensity in the heatmap for that cell will be equal to 600.
Downloading GPS Data
In addition to plot the heatmap and temporal visualizations, Geo-Location page allows you to download the plotted data as CSV or JSON format. For this purpose you need to click on the menu icon on the right side of the Go button, and select Download as CSV or Download as JSON, as shown below:
Note that the data downloaded here are processed data used by Geo-Location page to plot the visualizations. You can download raw GPS data from the Raw Data Download page.