Example Person-based GPS Tracked Data viewed in Google Earth
For over a decade, Dr. Doherty has been developing GPS-based
technologies for tracking human activity patterns, including especially
travel, exercise, and stationary activities. Although the first
attempts involved a suitcase full of equipment (!), he now uses
GPS-enabled smartphones such as the Blackberry. This further allows
the GPS data to be wirelessly transmitted to a central server for
storage, processing and display. Dr. Doherty has developed an
algorythm and system (patent pending) for automatically detecting a
wide-range of human activities (walking, driving, at-home, etc.), and
applied this system in studies of diabetic, elderly, disabled children,
as well as in a variety of consumer applications.
Example GPS Tracked Data
Listed at the bottom of this page are some example person-based 1-second GPS tracked data viewable in Google Earth. The raw data was collected using a Blackberry, compressed and transmitted wirelessly to a central servers, then processed to automatically detect the sequence of daily events (activities and trips). These events were then displayed in an interactive on-line prompted-recall diary. From there, the data was exported .kmz file, so that both the GPS raw data and activity-travel information could be viewed in Google Earth (http://earth.google.com/). Google Earth is free software that allows a variety of spatial data to be viewed from different perspectives on the earth - if you haven't tried it yet, it is well worth exploring.
How to View the Files
open the files and take note of the folders that appear at left, and
the GPS trace that appears on the surface of the earth. You are
encouraged to "follow your nose" and experiment with different views
and selections of data within the folders. You'll be surprised at just
how many different types of human behaviours are visible to the naked
eye. Of course, developing an algorithm to automatically perform this
detection is another matter, for which Dr. Doherty is deeply engaged.
Here are some further notes and tips on exploring and interpreting this
GPS Points: in addition to plotting the points by longitude/latitude, the time, heading, and connection between points are all visible to aid in interpretation. The triangular symbol used for each point points in the direction of movement. If the times becoming annoying, goto "Google Earth-Preferences/Options-Choose 3D Font" and set the font size to 4; this will hide the times from display.
Folders: the GPS data is organized into folders/sub-folders that represent the sequence of activities and trips automatically detected by the algorithm - a form of daily "diary". Expand/collapse these to view more/less detail by clicking on folders:
- The "Schedule" folder lists them in time-ordered sequence, showing the start/end time, event type (activity or trip) and location name.
- The "Events"
folder organizes the activities and trips by type. Choose this folder
or the schedule folder, BUT not both (since it displays the data twice
- The "Locations" folder contains single points of each location only (displayed as pushpins), calculated as the spatial average of all points associated with each activity.
Experiment with different data selections: click the whole "Schedule" folder to view all the data as a space-time path; alt, click only the trips within the schedule folder and the entire "Locations" folder, for a more concise view (this avoids the large clumps of GPS points typical of stationary activities). If you're interested only in certain types of activities, such as exercise or driving, explore the Events folder and click on only those of interest for display.
For more information on this data and how it is being used contact Dr. Doherty.
|2009||Google Earth File - Extensive Example of GPS Tracked Data, Including a Variety of Exercise||Document|
|2009||Google Earth File - Small Example of GPS Tracked Data, Automobile Focussed||Document|
|2009||Google Earth File - The "M-Spiral" Etch-a-sketch Application of GPS||Document|