Advantages of Dual-Frequency Satellite Systems
author: ralpu
October 26, 2021
The COROS Vertix 2 offers dual-frequency satellite system technology for activity tracking - the world's first GPS watch . In everyday use, it can be difficult to identify the differences between standard and dual-frequency GPS tracking. However, when performing activities in more demanding conditions, these differences are impossible to ignore. Let's take a closer look at this new technology used by the COROS Vertix 2.
Introduction
To understand how much of an impact dual-frequency GPS technology can have on activity tracking accuracy, it’s first necessary to explain how GPS watches track and measure activity. Simply put, single-frequency (standard) GPS watches measure distance by receiving information transmitted by radio signals from a single satellite above us. The watch then interprets this data and then estimates your current location based on all the information available.
For the most accurate measurement with a standard single-frequency GPS device, it is important that there is good quality communication between the watch and the satellites from which the information is received, without any obstacles. The problem arises if this communication is not of sufficient quality. In practice, such scenarios arise, for example, when performing an activity in a city between tall buildings, in mountainous areas, canyons, under overhangs, between cliffs, or in a forest with dense treetops above us. In these situations, it is very likely that a typical GPS device with single-frequency technology will encounter problems.
While typical single-frequency GPS watches can struggle with accuracy in a city with tall buildings, dual-frequency satellite technology is designed to improve accuracy in challenging environments. The key difference is that dual-frequency satellite technology allows for more information to be received from multiple satellites at the same time. What’s more, it uses different wavelengths of radio signals to distinguish one from another when recording a position, significantly reducing the risk of recording errors.
COROS Vertix 2 offers the incredible ability to communicate with all five major satellite systems - GPS, GLONASS, Galileo, QZSS and Beidou. In addition, it also offers dual-frequency satellite communication (L1 + L5), which was previously only available in the aviation industry. In practice, this means that the speed of GPS signal acquisition is much faster and the accuracy of the GPS signal is fundamentally better compared to the commonly used single-frequency L1 connection.
The dual-frequency satellite system technology allows the received information to be evaluated and identified as "direct" and "reflected" signals. This detail explains how this new technology has a much lower probability of error - see the image below. Furthermore, with dual-frequency satellite system technology, there is a much lower probability of data loss, as the additional communication line serves as a "backup".
In normal use of the watch - for example, when running, where there are no significant obstacles to receiving the satellite signal, the differences between standard single-frequency and advanced dual-frequency GPS recording may not be so significant. However, in demanding environments, where GPS recording typically fails, it is very strongly recommended to turn on All Systems + Dual FREQ On in the watch settings. It is also important to note that after turning on the All Systems + Dual FREQ On mode, the battery life of the COROS Vertix 2 is reduced from 140 hours to 50 hours. Therefore, it is recommended to use this mode only when necessary and if the conditions in which we move require it.
In this separate article from our COROS support, we explain the differences between the different GPS modes as well as typical scenarios when these modes should be used.
On any COROS GPS watch with dual-frequency satellite system technology, it is possible to define in which satellite location tracking "mode" we want to record the activity.
Activating the dual-frequency satellite system:
- Main screen hold the bottom side button select System More settings Satellite Systems Mode (connection mode) Standard GPS Only All Systems On All Systems + Dual FREQ On (all systems + dual frequency satellite communication).
Examples of using the All Systems + Dual FREQ On mode: rock and ice climbing on steep rock faces, in narrow canyons, hiking in dense forests, moving in high mountain environments, between old and high walls, cliffs. In general, it is recommended to use this mode if you require the highest possible accuracy of GPS recording and if the activity will not last longer than 50 hours.
