Introduction

UHF (Ultra High Frequency) radio technology is widely used for transmitting GNSS (Global Navigation Satellite System) data between a base station and a rover. Despite its advantages, being independent from any RTK network, users may encounter certain issues that can affect performance. This article outlines common issues and provides best practices to ensure optimal performance and reliability when using the GS05 UHF radio for GNSS RTK surveying.

By following these best practices outlined below, you can mitigate common issues and ensure reliable and efficient communication between your GS05 base and GS05 rover by using the UHF radio. Proper setup and awareness of potential interferences are crucial for achieving reliable and real-time GNSS data transmission, making your surveying tasks more effective and precise.

Best Practice information
1. Local Interferences and Reduced Baseline in Built-up Areas

Issue Description: Like every UHF radio communication, the signal might be susceptible to local interferences, and in built-up areas, the effective baseline may be reduced to a few hundred meters.

Best Practices: A good location of the GS05 base is key to ensure smooth communication to the GS05 rover. Choose a smart location with minimal obstructions between the base and rover.

2. Bandwidth Constraints and Pre-configured RTK Settings

Issue Description: Due to bandwidth constraints of the internal UHF radio, the RTK settings are pre-configured and cannot be changed by the user. For example, the RTK rate is set to a 2-second interval, which can result in longer time-to-fix and a slightly worse user experience compared to classical 1-second network RTK.

Best Practices: The user should be aware that the only difference is a longer time-to-fix when compared to a 1-second RTK rate. The accuracy and reliability of the RTK position remain on a same level.

3. Handling Excessive Satellite Data

Issue Description: Bandwidth issues might occur when tracking more than 40 satellites across 5 GNSS systems (GPS, GLO, GAL, BDS, QZSS), potentially causing RTK package delays and poor RTK performance.

Best Practices: Disable the least important satellite system(s) (e.g. GLONASS) to reduce the data load and improve RTK performance.

4. Interference from Other UHF Radios

Issue Description: The GS05 uses a low-power radio, and other higher-power radios (e.g., Satel radio) operating in the immediate vicinity and on a similar frequency band might cause interference, resulting in the loss of RTK data.

Best Practices: If different UHF bases operate at the same site, it is advised to use channels far away from each other to avoid interference.

5. External UHF Antenna

Issue Description: The UHF radio module requires an external antenna to send and receive data. Proper mounting of this antenna is key to ensuring good communication.
Best Practices: Ensure that the external UHF antenna is correctly screwed in, and the antenna is not damaged.

6. Base UHF Antenna Blindspot

Issue Description: The downwards looking UHF antenna on the base can be obstructed by the tripod setup, creating a "blindspot" where it is difficult for the rover to receive data.
Best Practices: Rotate the base to direct the UHF antenna towards the working area to ensure better signal reception.

7. Rover UHF Blocked

Issue Description: The carbon pole of the rover might block the UHF signal if the UHF antenna is hidden behind it or the user holding the rover setup blocks the signal.

Best Practices: Pay attention to ensure best possible line-of-sight from the rover’s UHF antenna to the base. Use an aluminum pole, which reflects the signal instead of blocking it.

8. Radio Protocol Compatibility

Issue Description: The GS05 UHF radio protocol is not compatible with other UHF radios, such as those from Satel and Trimble.

Best Practices: If interoperability with other UHF radios is required, use a CS20 with a CGR4 radio pack. This setup ensures compatibility with any Leica UHF base such as a GS16 and GS18 and provides extended UHF range.