Receptores GPS/GNSS e Sistemas de Navegação Inercial (INS and IMU)

GNSS (Global Navigation Satellite System) is a space-based system of satellites that provide the location information (longitude, latitude, altitude) and time information in all weather conditions, anywhere on or near the Earth to devices called GNSS receivers. GPS is the world’s most used GNSS system made by the United States.

INS (Inertial Navigation System) measures and integrates orientation, position, velocities, and accelerations of a moving object. INS integrates the device’s measured data, where a GNSS is used as a correction to the integration error of the INS orientation calculation.

Inertial measurement unit (IMU) is a device that measures accelerations and angular velocities. Some IMUs can also measure an external magnetic field with a magnetometer.

In an Inertial Navigation System (INS), IMU measurement data are used to calculate a unit’s orientation and relative changes in its velocity and position.

For navigation, they have to be properly initialized with absolute position and velocity. As velocity and position measurements are based on IMU measurement integration without corrections the INS solution drifts over time depending on IMU performance. Usually, GNSS measurements are used for correction in GNSS aided INS.

IMU (Inertial Measurement Unit) device is an INS device, which has a built-in three-axial accelerometer and gyroscope. An additional magnetometer can be added to provide the right heading on the Earth.

Dewesoft supports GPS and GLONASS positioning GNSS systems, which are currently the only systems with operational satellites all around the globe. Topcon receivers, DS-IMU1 and DS-IMU2 support also Galileo and BaiDou GNSS systems.

RTK (Real-time Kinematics) is a positioning technique that enhances the accuracy of GNSS positioning systems up to 1 cm. It uses an additional GNSS receiver (base station) located on Earth that calculates the correction of satellite signals from the space and sends correction information to other GNSS receivers (rovers) on Earth. 

By default GNSS devices have from 3 to 1.2 m standalone accuracy, 3 to 0.3 m with SBAS correction, 0.2 to 0.1 m with Omnistar correction (only available with for DS-IMU2 device) and up to 0.01 m with RTK correction system.

GNSS systems and devices have accuracy from 3 to 1.2 m in the standalone version. Higher accuracy can be achieved by different correction methods such as SBAS, Omnistar, and RTK (Real-Time Kinematics). RTK correction provides accuracy up to 1 cm.