Surveying of Point Features Using Duel Frequency GPS

In order to create a topographic map it is imperative to understand the Dual Frequency GPS equipment.

In order to do this we have to know what a dual frequency receiver does. This is a signal capturing system that can select and simultaneously receive signals on two frequency channels during a specific time period. This is a good system to use to gathering point data that is incredibly accurate and can accurately gather points to within a centimeter of where they were taken. In this introductory lesson we learned how to take different points and then use the data to create a map in ArcGIS.

 RTK Unit 

The study area that we have selected was the area that is outside of Davies and UWEC Phillips Science Hall. This area allowed us to collect numerous different points such as trees, garbage cans, and light polls. This was useful as an introductory course in the Surveying. The surveying equipment utilized is the RTK GPS Unit. RTK stands for Real Time Kinematic. It is used for extremely high accurate positional accuracy by using a consistent connection to the internet via Wi-Fi. Every time we collect a point using the RTK GPS Unit it collects 30 points and averages all of them out. This allows for extremely accurate data collection.

RTK Unit Screen 

When collected there is also XYZ data from the GPS unit. This can then be used in ArcGIS by selecting the tool import XY and map out the points in ArcGIS. The points can then be redone in ArcMap by selecting the projection which is UTM zone 16. The XYZ data can then be used to map where the points will be located. From here it was simply selecting the points in the attribute table by what they were in the definition which was entered into the GPS unit upon capture. From here it is simple to use this data to create a basic survey map.

The results of this data show very accurate GPS collected points using the RTK GPS Unit. This is a useful tool for surveying points that require accurate information. An example of this would be road surveying and forestry work. The results of the captured points are incredibly accurate. This RTK GPS Unit also has the added benefit of allowing us to input attribute data directly on capture versus where it would be necessary to know what to capture before surveying with other equipment.  

Collected Survey Points 

To conclude the RTK is a useful tool when accuracy is important to the application at hand. The only downside is that this a large unit and is slightly cumbersome to carry around everywhere. The GPS unit is also great since it allows on the fly attribute creation. Overall this is a very useful tool that I look forward to working with in the future.