Your rover depends on global positioning to determine its location and to navigate familiar and unfamiliar terrain successfully. The primary reason to increase the number of receivers on your GPS rover is heading accuracy. Upgrading from a single system to multiple receivers is typically a cost-effective method of improving accuracy for geolocation. Increased heading accuracy for geolocation is the single most important reason to add an additional GPS to your rover GPS array. This additional GPS sensor is typically called Dual Compassing. Dual compassing can actually increase the accuracy of your GPS signal. 


The Importance of Heading Accuracy for Your GPS Rover

Which direction is your rover facing? Not all rover GPS systems require a high degree of heading accuracy for navigating and operating autonomously. Those that do, however, like antenna pointing and mapping & surveying devices, often rely on extreme accuracy to maintain safe distances and to ensure proper orientation for various tasks and activities. A magnetometer with a single global positioning receiver can provide moderate degrees of accuracy, especially when supplemented with inertial measurement units (IMUs) and other devices, but adding a GPS to your rover can allow it to operate within a smaller margin of error with higher reliability when traveling autonomously. 


Integrating GPS Receivers With Other Technologies

Rover GPS systems have traditionally been paired with IMUs to provide a backup method of calculating the location of autonomous devices in controlled conditions. IMUs measure the speed of motion, the direction of motion and certain magnetic fields to provide an approximation of the location of autonomous systems on a particular trajectory. While the sensor fusion of GPS with IMU does not produce exact locations and precise accuracy, error and drift rates are far better than either of these systems’ ability to manage alone.

Interestingly, the additional GPS sensor does not always need to be attached to the rover itself. Positional data in relation to a fixed/surveyed point can add a surprising amount of positional accuracy as well. 

Real-time kinematic (RTK) positioning is typically used to correct for errors that can occur when the global positioning system signal is scrambled due to atmospheric noise or even if it is lost for a short period of time. RTK systems consist of at least two receivers, one of which is on the rover and another that stays stationary at a distance from the autonomous system. The stationary receiver provides a valuable baseline for the signals received by your roving device.


Key Reasons to Add a Dual Compassing GPS to Your INS

While one GPS can often provide basic navigating and positioning information for your autonomous system, deciding to add a GPS to your existing array can often provide cross-checking capability and increased heading accuracy and reliability for navigation. One of the best reasons to add a GPS is the ability to double-check the location and heading data against another source. The combination of these two GPS sensors, along with other inertial data, are fed into a Kalman Filter processing system that fuses the sensor data and filters out the noise. 

This is the secret sauce of an INS and can make huge differences in performance. A dissertation submitted to and accepted by Purdue University highlights the benefits of additional GPS receivers in terms of added accuracy for robotic navigation. Daniel Schrader’s master’s thesis focuses on the advantages of combining multiple low-cost receivers and microcontrollers for autonomous navigation. The data collected by multiple GPS systems can be compared and collated to produce a consensus location, which can significantly improve accuracy for your rover GPS system’s navigation processes. This mentality heavily influenced the developmental engineering process and mindset for the Dual Compassing Micro INS from Inertial Sense and is one of the reasons our sensors can be so accurate at such a low cost and physical footprint.


Why You Should Add a GPS to Your Rover

Accuracy is by far the most important reason to add a GPS to your roving or autonomous systems. Knowing precisely where your device is at any given time can reduce the risk of accidents in the working environment and can promote greater productivity and reduced downtime when your rover is in operation.


The Value of Professional Help

Creating the right configuration for your rover is key to its proper function in real-world situations. Working with a company that specializes in software modules and precision components for autonomous systems can help you to achieve the best results when adding specific capabilities to your rover. Enlisting the help of a company with proven experience in this field is a solid step in the right direction for creating functional autonomous systems, rovers and robots.

At Inertial Sense, we offer industry-leading precision sensors, software modules, and other components necessary for your autonomy and navigation projects. We work with our clients to provide the most accurate advice and guidance on the right sensors and configurations for your roving autonomous systems. Contact us online or call us at 801-406-3163 to touch base with our team. We are here to provide the help you need to succeed in the fast-paced field of robotic autonomy and navigation.


Learn More:

What’s the Difference Between GPS and GNSS?

What’s The Difference Between GPS and GPS INS?

RTK Rover & Base – What’s The Difference Between RTK and DGPS?