Ellipse-E Optimal GNSS integration & versatile interfacing

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The difference between an Inertial Measurement Unit (IMU) and an Inertial Navigation System (INS) lies in their functionality and complexity.

An IMU (inertial measuring unit) provides raw data on the vehicle’s linear acceleration and angular velocity, measured by accelerometers and gyroscopes. It supplies information on roll, pitch, yaw, and motion, but does not compute position or navigation data. The IMU is specifically designed to relay essential data about movement and orientation for external processing to determine position or velocity.

On the other hand, an INS (inertial navigation system) combines IMU data with advanced algorithms to calculate a vehicle’s position, velocity, and orientation over time. It incorporates navigation algorithms like Kalman filtering for sensor fusion and integration. An INS supplies real-time navigation data, including position, velocity, and orientation, without relying on external positioning systems like GNSS.

This navigation system is typically utilized in applications that require comprehensive navigation solutions, particularly in GNSS-denied environments, such as military UAVs, ships, and submarines.

Real-Time Kinematic (RTK) is a precise satellite navigation technique used to enhance the accuracy of position data derived from Global Navigation Satellite System (GNSS) measurements. It is widely employed in applications such as surveying, agriculture, and autonomous vehicle navigation.

By using a base station that receives GNSS signals and calculates its position with high accuracy. Then it transmits correction data to one or more roving receivers (rovers) in real-time. The rovers use this data to adjust their GNSS readings, enhancing their positional accuracy.

RTK provides centimeter-level accuracy by correcting GNSS signals in real time. This is significantly more precise than standard GNSS positioning, which typically offers accuracy within a few meters.

The correction data from the base station is sent to the rovers via various communication methods, such as radio, cellular networks, or the Internet. This real-time communication is crucial for maintaining accuracy during dynamic operations.

Precise Point Positioning (PPP) is a satellite navigation technique that offers high-precision positioning by correcting satellite signal errors. Unlike traditional GNSS methods, which often rely on ground-based reference stations (like in RTK), PPP utilizes global satellite data and advanced algorithms to provide accurate location information.

PPP works anywhere in the world without the need for local reference stations. This makes it suitable for applications in remote or challenging environments where ground infrastructure is lacking. By using precise satellite orbit and clock data, along with corrections for atmospheric and multipath effects, PPP minimizes common GNSS errors and can achieve centimeter-level accuracy.

While PPP can be used for post-processed positioning, which involves analyzing collected data after the fact, it can also provide real-time positioning solutions. Real-time PPP (RTPPP) is increasingly available, allowing users to receive corrections and determine their position in real time.

GNSS stands for Global Navigation Satellite System and GPS for Global Positioning System. These terms are often used interchangeably, but they refer to different concepts within satellite-based navigation systems.

GNSS is a collective term for all satellite navigation systems, while GPS refers specifically to the U.S. system. It includes multiple systems that provide more comprehensive global coverage, while GPS is just one of those systems.

You get improved accuracy and reliability with GNSS, by integrating data from multiple systems, whereas GPS alone might have limitations depending on satellite availability and environmental conditions.

GNSS represents the broader category of satellite navigation systems, including GPS and other systems, while GPS is a specific GNSS developed by the United States.