How it Works

An Introduction

Single Reference Station RTK

Network RTK

Network – RTK Is It Worth It?

Example – Using Network RTK

Remember

Different Methods

Example – Using Network RTK

In this example there are two UK 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 Leica GPS1200 Rover and a GSM or GPRS (Internet) mobile phone to receive RTK corrections from SmartNet UK. Surveyor A takes the following steps to complete Job 1 (Fig. 4):

  1. Drive to Job.
  2. Setup the rover.
  3. Connect to SmartNet UK to receive RTK corrections.
  4. Walk around and measure points.
  5. Disconnect from SmartNet UK.
  6. 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.

Surveyor A completing Job 1

Figure 4: Surveyor A completing Job 1

Surveyor A completing Job 2

Figure 5: Surveyor A completing Job 2

Surveyor B

Surveyor B is using a base station and rover pair with GSM mobile phones for the communication link. Surveyor B takes the following steps to complete Job 1 (Fig. 6):

  1. Drive to Job.
  2. Setup base station in a suitable location, which may or may not be adjacent to the working area.
  3. Measure height of base station.
  4. Start the base station broadcasting RTK corrections.
  5. Go to the start of the job.
  6. Setup the rover.
  7. Connect rover to the base station to receiver RTK corrections.
  8. Walk around and measure points.
  9. Pack up rover.
  10. Return to the base station.
  11. Re-measure height of base station (to check that it has not moved).
  12. 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 favour 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.

Surveyor B completing Job 1

Figure 6: Surveyor B completing Job 1

Surveyor B completing Job 2

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 flat.
  • The base station radio battery going flat.
  • 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

In contrast, by using SmartNet UK, Surveyor A could achieve consistent accuracy for both jobs. No sacrifices were made. RTK Networks The Future

Further Information

More information on RTK Networks can be found on our Product Overview website.

Please contact your local Leica representative if there are specific topics you would like covered in these Papers. We welcome all suggestions for TPS1200, GPS1200, specific applications or LGO. We look forward to receive your ideas.