The Impact of High Accuracy GPS in Mobile GIS Data Collection
Posted by Tim Clark on Wed, Oct 26, 2011 @ 08:20 AM
As part of our ikeGPS software suite we have an High Accuracy GPS option, hence our fancy acronym HAGO. I have seen many heated debates break out when people start discussing the details and nuances of what and how GPS works, especially when it comes to accuracy. The technical details can be quite complex, so I won’t address them in detail in this post, but what I will do is discuss how high accuracy can greatly impact your mobile GIS data collection results.
In the chart above, the dots are all from a single set of GPS data collection points measured with an ikeGPS mobile GIS device, but one set with HAGO (Blue) software applied and the other without HAGO (Red). Out of the box (without HAGO) ikeGPS is very robust and accurate. But if you want more accuracy, this is where HAGO comes in. HAGO will level out the position errors of your GPS data by using a satellite-based augmentation system (SBAS). This is a real time system that supports wide-area or regional augmentation through the use of additional satellite-broadcast messages. The graph below also illustrates this. As we move from left to right as time increases, HAGO errors drop off, while non-HAGO errors increase and become less stable.
The chart below is the same data as the first chart but with directional averaging and a mean average applied to the points measured with HAGO and without HAGP. This simplified view illustrates the overall improved accuracy of using HAGO software in GPS data collection.
Advantages of HAGO
- Software only, factory install or upgrade to all ike1000 Series devices
- No active control or input necessary from the user
- Provides sub-meter (CEP) accuracy for GPS measurements
If this sub-meter data and accuracy is still not up to par for you, contact ikeGPS support. We have some additional “SUPER” HAGO options available. They are not as simple as a software update like HAGO but involve some hardware add-ons. We will be discussing some of these advanced GPS options, like RTK, very soon.