Background<\/h3>\n
Capturing the location is only useful if you are creating a survey for a Snap WebHost edition that is likely to be seen on a mobile device, or a mobile survey for Snap Mobile Anywhere. The survey must be running on a device which can capture geolocation information, (such as a GPS-enabled tablet).<\/p>\n
Location data is only available in Snap WebHost and Snap Mobile Anywhere editions. It’s stored in the ID.location variable in WGS84 (World Geodetic System<\/a>) format. You can extract the separate elements of the location data by using the system patterns provided. The worksheet includes two examples showing you how to do this. You can also export the data for external analysis.<\/p>\n The two main methods of getting a location are using GPS or using information from mobile phone masts. GPS is more accurate but uses more battery power, so people may disable it.<\/p>\n You have no control over whether people permit the survey to use geolocation information, or whether their device is able to provide accurate geolocation information. For example, if people are looking at surveys with a PC, the location provided may be that of a router.<\/p>\n When running the survey, the geolocation can only be stored if the device has the means and the browser or Snap Mobile Anywhere has the permission to capture location data.<\/p>\n It’s best if you know what device your survey is running on, for example, if the survey is carried out by interviewers using Snap Mobile Anywhere.<\/p>\n <\/a><\/p>\n <\/a><\/p>\n <\/a><\/p>\n It is possible to change the settings to make the device spend a longer or shorter time looking for the location if the defaults are not adequate.<\/p>\n <\/a><\/p>\n You must now publish the survey and upload it to Snap WebHost<\/span>. This is described in the section Upload the published survey to Snap WebHost<\/span> in the Getting Started guide. If the survey is for Snap Mobile Anywhere<\/b> you must also assign it to interviewers. This is described in the worksheet: Setting up surveys for Snap Mobile Anywhere<\/a><\/p>\n <\/a><\/p>\n The most common method of using geolocation data is to export the data and use it with a mapping API, such as google maps (see https:\/\/developers.google.com\/maps\/<\/a>) or Open Street Map (see http:\/\/wiki.openstreetmap.org\/wiki\/API<\/a>).<\/p>\n You can export the data directly in WGS84 format or create derived variables to hold the data in a specified format.<\/p>\n Extract the longitude and latitude to a single derived literal variable.<\/p>\n This example tests to see if an error has been received, so only valid geolocations are stored. It then stores the latitude and the longitude, separated by a comma. It assumes that you have added the paradata ID.location<\/b> to your survey.<\/p>\n Name<\/span><\/strong>: LatLong<\/p>\n Label<\/span><\/strong>: Latitude and Longitude<\/p>\n Type<\/span><\/strong>: Derived (the variable will derive its data from other existing variables).<\/p>\n Response<\/span><\/strong>: Literal<\/p>\n NA<\/span><\/strong>: Values<\/strong>:<\/span> The : is a literal operator in Snap. It allows you to put different values together<\/p>\n<\/li>\n <\/a><\/p>\n This worksheet has described how to add the geolocation variable to your survey and export the collected data. It has explained some of the issues with collecting location data. It has also provided an example of cleaning the data to remove errors.<\/p>\n For further information about patterns in Snap, see: Introduction to patterns<\/a>.<\/p>\n For a full list of the system patterns available, see: System patterns<\/a>.<\/p>\n For more information about surveys on mobile devices see Getting Started with <\/a>Snap Mobile Anywhere<\/a><\/b> and the worksheet Setting up surveys for Snap Mobile Anywhere<\/a>.<\/p>\n If there is a topic you would like a worksheet on, email to snapideas@snapsurveys.com<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Issues with capturing locations<\/h4>\n
Summary of steps<\/h3>\n
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Step 1: Enable geolocation in your survey<\/h4>\n
\n
![\"questionnaire](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2014\/10\/q_prop.png\")
<\/a>\u00a0to display the Questionnaire<\/b>Properties<\/b> dialog box.<\/li>\n
\n![\"par_geoloc_hl\"](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2014\/10\/par_geoloc_hl.png\")
<\/a><\/li>\n![\"loc_quest\"](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2014\/10\/loc_quest.png\")
<\/a><\/li>\n![\"sh_loc_hid\"](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2014\/10\/sh_loc_hid.png\")
<\/a><\/p>\n<\/li>\n![\"save\"](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2014\/10\/save.png\")
<\/a>\u00a0to save the changes to the questionnaire.<\/li>\n<\/ol>\nStep 2: Configure how accurate the data is<\/h4>\n
\n
![\"q_prop\"](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2014\/10\/q_prop1.png\")
<\/a>\u00a0to display the Questionnaire<\/b>Properties<\/b> dialog box.<\/li>\n
\n![\"par_geoloc_conf_hl\"](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2014\/10\/par_geoloc_conf_hl.png\")
<\/a><\/li>\n
\n![\"geoloc_conf\"](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2014\/10\/geoloc_conf.png\")
<\/a><\/li>\nStep 3: Publish the survey and prepare it for interviewers<\/h4>\n
Example of extracting the data for analysis<\/h3>\n
To export the data:<\/h4>\n
\n
![\"Data](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2012\/10\/data.png\")
<\/a>\u00a0to the Data Entry <\/span>window.<\/li>\n![\"dat_exp_csv_loc\"](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2014\/10\/dat_exp_csv_loc.png\")
<\/a><\/p>\n<\/li>\nModifying the data using a derived variable<\/h4>\n
\n
unless ((ID.location as geo unavailable) == \"\")<\/code><\/p>\nID.location as geo latitude:\", \":ID.location as geo longitude<\/code><\/p>\n![\"der_lat_lon\"](\"https:\/\/www.snapsurveys.com\/support-snap11\/wp-content\/uploads\/2014\/10\/der_lat_lon.png\")
<\/a><\/p>\n<\/a>\u00a0to save the variable.<\/li>\n<\/ol>\nConclusion<\/h3>\n