RF ToF Proximity Detection System (PDS) technology utilises Radio Frequency (RF) communications to detect, classify, track and communicate between vehicles, assets and personnel. Radio communication is typically performed with radio transmitters, receivers and transceivers (referred to as radio tags). Radio tags are one of the most prevalent technologies used in PDS/CAS solutions.
Working Principles
RF ToF PDS technology requires that single or multiple radio transceivers are mounted onto both the local and remote object. Ranging between multiple radio tags allow a PDS to determine both the distance and position of two objects with respect to each other. The communications between radio tags also allow for the identification of individual objects, simplifying the detection and classification process.
There are many different techniques that are used to estimate the distance and position between radio tags; however, it is believed that most of the PDS solutions use: (a) Time-of-Flight (ToF)-based methods for ranging; and (b) multiple transceivers for the position estimation. Ultra-Wideband (UWB) (operating in the range of around 3 to 10 GHz) transceivers are commonly used in PDS due to their relatively high level of accuracy and robustness to multipath effects. RF ToF systems use similar technology to RADAR; however, RADAR-based solutions rely on passive radio reflections and do not require the installation of tags onto remote objects.
Advantages
- Relatively high accuracy
- Suitable for both surface and underground operations
- Suitable for long-range detection
- Relatively robust to terrain and environmental effects
Limitations
- Requires infrastructure to be installed onto remote objects
- Susceptible to Electromagnetic (EM) interference
- Communications require Line-of-Sight (LoS)