GPS and Location Capturing in SurveyToGo

GPS Overview:

Most Android devices nowadays provide the ability to locate the geographical location of the device. This tutorial will introduce you to the basics of GPS functionality on your android device and how SurveyToGo utilizes that location information to allow the Geo-Tagging of interviews as well as indicate geographical locations during an interview.

Important Note: GPS location is captured by SurveyToGo only on Android devices and not on by the PC Survey on Windows based devices (tables/laptops).

The guide is divided into two parts:

Part 1: GPS and location basic functionality on Android devices

Part 2: GPS and location information utilization in SurveyToGo

 

Part 1: GPS Basic Functionality

Android devices nowadays come with the ability to locate a geographical location on earth. It can utilize a GPS receiver if available on the device, WiFi positioning if available and wireless (cell) positioning when available. What will the Android OS will utilize on a specific device depends on the location services definition of the device and if they were enabled.  

The Global Positioning System (GPS) is a space-based navigation system that provides location and time information anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. The United States government created the system, maintains it, and makes it freely accessible to anyone with a GPS receiver. A true hardware GPS receiver doesn't need an internet connection to function. Some Android devices today come with an A-GPS (Assisted GPS) that makes the process of finding a GPS Sattelite faster, it is a receiver that uses the cellular towers. Very often cellular network towers have GPS receivers (or a base station nearby) and those receivers are constantly pulling down satellite information and computing the data. This data is then passed on to the cellular phone an internet connection to function so pay attention when reviewing a specific device and if you plan to utilize it in areas where connection is or is not available. 

The GPS receiver is normally turned off on your device. When you have defined the location services to utilize the GPS for positioning and activated the location services It becomes available for reception.  When open for reception it is a high battery consumer. For that reason the GPS receiver is not always open but is being asked by the Android OS to open the antennas for reception only once in a while at a certain frequency (depending the App that is asking for location information). Hence, when using known navigation app’s (Waze for example) you can notice your battery power is being consumed very fast. In this operation mode the Android OS constantly receives the latest GPS location received from the GPS receiver on your device.

In order to receive GPS data, your GPS receiver e.g. (device) should be under open skies. If located within any indoor building, the GPS will not be able to receive its location transmissions transmitted by the GPS satellites, as the transmissions just can’t go through the walls and are being blocked.

If a transmission is blocked due to being indoors, Android can get the location  by using your Wi-Fi connection and\or 3G services, if the location services are configured in such a way on your device.

Please note that GPS locations captured through Wi-Fi\3G are much less precise than the hardware GPS receiver and sometimes may result in a very in-accurate GPS locations.

To summarize this part the Android OS is centrally managing and gathering the location information of the device.  It does it by querying its available resources as available on the device and as been defined in the location services definitions (GPS, Wi/FI, 3G). An App on the device can instruct the Android OS to request more or less frequent sampling if required. The Android OS will provide the App the latest most accurate location it received.

 

Part 2: GPS Interface and functionality in SurveyToGo

SurveyToGo utilizes the Android capabilities to obtain location information of the device. Location data is used for quality control purposes, understanding where the field it is at during the project and other specific survey related needs such as specifying Geo locations the interviewer is passing through during the interview.

Use GPS: In order to enable the GPS/location capturing functionality within SurveyToGo, please note that the Location Services must properly configured and enabled, in addition to the ‘Use GPS’ in SurveyToGo setting.

GPS Sampling Frequency: surveyToGo will ask the Android OS for the most updated location with a given frequency. The default frequency is 5 minutes, meaning that from the moment you have opened SurveyToGo, every 5 minutes SurveyToGo will ask for the latest location obtained by the Android OS. You can change this sampling rate if a more frequent sampling is required based on your surveying needs. Please note that higher frequency means higher battery consumption. The setting can be done with the following setting:

Use Only GPS Hardware: Enabled by default and instructs SurveyToGo to consider only location information that was obtained by the GPS hardware component and ignore such information that was obtained from the 3G & Wi-Fi providers. As explained it ensures an accurate positioning but will be less available in certain cases (when interviewing indoors etc).

In order to see if your GPS is properly configured and receives an updated location information follow this tutorial:

How to validate that the App can obtain valid location information 

SurveyToGo utilizes the location information it receives for 2 major needs: 

A. Automatically Geo Tagging Interviews

B. Interviewers positioning

Let’s go over both features.

A. Automatically Geo Tagging Interviews

SurveyToGo automatically associates to every interview when it starts the last known location it has received from the Android OS. This allows you to later verify that the interviews was indeed collected where planned/required. You can the review this data when reviewing the interview on the Operations Console or when exported.

Use this tutorial to understand how you can view the collected location information of an interview: How To View Interviews Location Data


Make sure your devices are properly set and Instruct your surveyors to follow How to validate that the App can obtain valid location information before starting each interview to ensure a high rate of location capturing.

B.  Interviewers positioning

GPS Tracking allows you to know where your surveyors are and  the route they have been taking while interviewing.

Here you can find specific overview of its features:
GPS Tracking in SurveyToGo

When SurveyToGo is opened our system is configured to record the latest valid location every given frequency ( 10 minutes - to determine the device location).
Those readings will eventually ‘build’ your surveyor's route.

The blue pins are those system captured GPS readings that were captured for location tracking.The small S symbols corresponds to locations where an interview started.

When looking at the ‘Latest Locations’ you would see that latest GPS location captured by the system’s 10 minute default time out, disregarding the interview location capturing.

If you wish to disable this interviewers location capturing, you can do so through the GPS settings, by disabling the following feature:

For further location related functionality you can refer to:

How-to-use-Geo-Fencing-with-SurveyToGo
How-To-use-Location-Questions

That’s it!

 

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  • Good stuff! Thanks guys.

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