Tech Chat | Understanding Main Functional Modules in RTK GNSS Receivers

In the previous blog, we explored the communication system built into the mainboard of an RTK GNSS receiver — detailing how it supports data transmission through various wireless and wired interfaces. Continuing this series, today's blog will focus on the main functional modules integrated into the receiver's mainboard. These components are crucial for achieving high-precision positioning and enabling smart field applications.

Let's take a closer look at the core modules commonly found in modern RTK receivers and what each one is responsible for:

1. GNSS Engine

Core Role: Satellite signal processing and positioning computation

As the "brain" of the receiver, the GNSS engine is responsible for tracking satellite constellations (GPS, BDS, GLONASS, Galileo, etc.), decoding signal data, and computing positioning results. Modern GNSS engines support multi-constellation and multi-frequency tracking, significantly improving fix speed and reliability in challenging environments such as urban canyons or under heavy canopy.

You may also find:

• Dual-antenna GNSS modules for parallel positioning and heading calculation
• Built-in real-time correction processing (RTK, PPP, SBAS)

2. IMU (Inertial Measurement Unit)

Core Role: Tilt compensation for efficient surveying

The IMU module integrates accelerometers and gyroscopes to detect the range pole's angle and compensate for tilt. This enables tilt surveying, allowing surveyors to collect accurate points without needing to keep the receiver vertically aligned, improving both flexibility and efficiency in the field.

3. Storage

Core Role: Internal data recording for post-processing

Onboard storage allows GNSS raw data (such as RINEX or proprietary binary formats) to be logged directly within the receiver. This is especially beneficial for static surveys and applications that require post-processing.

You may also find:

• Storage capacities of 8GB or more
• Adjustable logging intervals and supported file formats

4. Laser Module

Core Role: Non-contact distance measurement

The integrated laser module is used for laser surveying, allowing users to measure targets without physically reaching them. Often working in combination with the IMU, this module is particularly useful in dangerous, wet, or hard-to-reach environments, delivering both safety and efficiency.

5. Camera Module

Core Role: Image-based AR stakeout and visual guidance

With a built-in camera, the receiver supports functions like photo documentation, live video guidance, and augmented reality (AR) stakeout. As visual surveying becomes more prevalent, the camera module helps users interact with the field environment more intuitively, boosting both accuracy and productivity.

Each of these modules plays a critical role in making RTK GNSS receivers more powerful, intelligent, and adaptable. As surveying tasks evolve beyond traditional workflows, the modular mainboard design ensures that the receiver can support a growing range of smart features in a compact and rugged form factor.

Stay tuned for the next Tech Chat, where we'll continue our exploration into the internal architecture of RTK receivers.