How it works...

Example — Using Network RTK

In this example there are two surveyors, Surveyor A and Surveyor B. Both surveyors have the same two jobs to complete, Job 1 and Job 2. Each job takes 30 minutes to walk around all the required points. The jobs are spaced 35 km apart.

Surveyor A

Surveyor A is using a Network RTK capable GNSS Rover to receive RTK corrections from SmartNet. Surveyor A takes the following steps to complete Job 1 (Fig. 4):

Drive to Job.
Setup the rover.
Connect to SmartNet to receive RTK corrections.
Walk around and measure points.
Disconnect from SmartNet.
Pack up rover.

Surveyor A then repeats steps 1 6 for Job 2 (Fig. 5) with the final step of driving back to the office.

Figure 4: Surveyor A completing Job 1

Figure 5: Surveyor A completing Job 2

Surveyor B

Surveyor B is using a base station and rover either with either a traditional RTK radio setup or a pair with cellular data devices providing the communication link. Surveyor B takes the following steps to complete Job 1 (Fig. 6):

Drive to Job.
Setup base station in a suitable location, which may or may not be adjacent to the working area.
Measure height of base station.
Start the base station broadcasting RTK corrections.
Go to the start of the job.
Setup the rover.
Connect rover to the base station to receiver RTK corrections.
Walk around and measure points.
Pack up rover.
Return to the base station.
Re-measure height of base station (to check that it has not moved).
Pack up base station.

Surveyor B then repeats steps 1 12 for Job 2 (Fig. 7) with the final step of driving back to the office.

Surveyor B could also choose to leave the base station setup at Job 1 and carry on to Job 2 (Fig. 8).

In this case, by increasing the distance between the rover and the reference to 35 km, there would be an associated decrease in accuracy of the rovers computed position. Therefore, Surveyor B would be sacrificing accuracy in favor of saving time on the setting up of the base station. Surveyor B would also have the additional step of collecting the base station before returning to work.

Figure 6: Surveyor B completing Job 1

Figure 7: Surveyor B completing Job 2

Summary

By not needing to setup a base station, Surveyor A had a lot less work to do in the field than Surveyor B. In addition, Surveyor A avoided potential risks such as:

The base station battery going dead.
The base station radio battery going dead.
The base station being moved (e.g. cattle, wind, traffic or thieves!).

Surveyor B could have setup and packed up their base station twice, or simply left the base station at the first setup sacrificing accuracy for convenience. So what is the real world cost of performing the survey using Surveyor B's procedures over the course of a year? Well if we assume that it takes an hour to setup and tear down the base station and Surveyor B uses GPS 3 days a week, then it is simply $ 100 / hour x 3 days a week x 50 weeks a year, or $ 15,000 in lost production time!

In contrast, by using SmartNet, Surveyor A could achieve consistent accuracy for both jobs, as well as dramatically increased his productivity. No sacrifices were made.