5 Things to Consider for Integrating GPS and GIS

by Michele Mattix

Collecting field data using GPS technology has never been easier.  The equipment is smaller and lighter.  Many modern GPS units are all-in-one handheld devices that combine the GPS antenna, receiver, and field computer into one device.  Color screens that operate by touch make navigating the field computer a breeze.  If the unit does not have a built-in digital camera, laser rangefinder, compass, or other device, then it probably has Bluetooth and/or WiFi to enable wireless communication with such peripheral devices.

With so many field data collection devices on the market, it can be overwhelming to figure out which one is the best for you.  Here are some things to consider when shopping for GPS field equipment that will be used to collect GIS-ready data.

1.  There is a difference between professional and recreational GPS units. 

One is designed for a professional GIS-GPS workflow, the other for hiking, running, and fishing.  If you need high-accuracy GIS-ready field data that includes all attributes then recreational GPS units will not work for you.  Ditto if you want an easy workflow that will take you from office to field and back to office seamlessly.  Recreational GPS units simply are not designed for a GIS workflow.  Many organizations use them, however, because they are considerably cheaper than professional grade GPS.  What they save in money, however, they make up for in time and frustration. Using a recreational GPS unit in a GIS workflow adds a lot of extra work.

 

2.  Field software options vary among different GPS units. 

GPS manufacturers typically have their own field software that will work only on their units.  Some of these applications are excellent and others terrible.  Other field software, like ESRI’s ArcPad, work on any Windows Mobile device.  Know what field software options are available for the unit you are considering.  Make sure that the software can connect with the GPS receiver (many GPS manufacturers program their field software to not recognize a competitor’s GPS receiver).

 

3.  How easily does the office and field software communicate? 

Assuming you’re using ArcGIS in the office, make sure you know the workflow for getting your GPS field data into your GIS.  Products like ArcPad make this very easy.  Toolbars in ArcMap allow you to check-out your GIS data for the GPS unit and then check-in your field edits.  GPS manufacturers often have their own proprietary field and office software.  This adds an extra step or two to get your field data into your GIS.

 

4.  Wireless communication between your GPS unit and other field equipment. 

Would you like to add digital photos of field assets to your GIS?  You can do this with the right field equipment.  Find out before you buy a GPS unit if it will communicate with a digital camera, laser rangefinder, or other devices you plan to use AND if you need additional software or hardware to do so.  You want wireless communication between the device and your GPS unit – cables are problematic for field data collection.

 

5.  Options for differentially correcting your GPS data vary.

Nearly all current GPS units are WAAS or SBAS capable which means your GPS data are differentially corrected in real-time.  SBAS provides a level of accuracy that is much better than autonomous GPS, but there are other methods of differential GPS than can do better than SBAS.  Ask if a GPS unit you’re considering support other methods that may be of interest to you.  If you plan to post-process your GPS data to obtain higher accuracy in your data, make sure you understand what is involved.  Usually you will need to purchase additional software.  Post-processing adds a level of complexity to your workflow that most GPS manufacturers and salespeople gloss over.  Be sure you get the facts straight before you buy.

Our custom GIS/GPS courses are designed to help educate you so you can make smart choices about GPS and GIS equipment integration.  Our Introduction to GPS Technology training video is a great place to start.