Overcoming Challenges in 3D Sensor Fusion Labeling for Autonomous Vehicles

July 06, 2023

The field of sensor fusion is experiencing rapid growth and transformation, fueled by the increasing demand for autonomous vehicles. According to a report by Mordor Intelligence, the sensor fusion market will reach an impressive $13.62 billion by 2026. 

With onboard cameras, LiDARs, and millimeter-wave radars, driverless vehicles can effectively capture real-time information, monitor changes in their surroundings, and make informed decisions. However, integrating data from diverse sensors has many challenges, and this blog will delve deep into the challenges encountered in 3D sensor fusion labeling for autonomous mobility while exploring potential solutions to overcome them.

Challenges of Multi-Sensor Fusion Data Labeling

With the rise of sensor fusion as the preferred approach for autonomous mobility, the paradigm of data annotation projects has also shifted. From the traditional annotation of separate 2D images and 3D point clouds, the focus is now to expand to 2D-3D sensor fusion annotation. 

Let us see some data challenges in 2D-3D sensor fusion for autonomous mobility.

Huge Volumes of Data

As the demand for labeled data grows, the sheer volume of data that needs to be processed, stored, and organized becomes overwhelming. Efficient data management systems and infrastructure are essential to handle the massive influx of data, ensuring proper storage, accessibility, and retrieval for labeling purposes.

Time-consuming Process

For training machine learning or deep learning-based object detectors and assessing the performance of existing detection algorithms, the presence of ground truth is crucial. However, creating ground truth data is often time-consuming, involving manually labeling videos frame by frame. This labor-intensive process is necessary to establish accurate annotations for training and evaluation purposes. 

Increasing Labeling Complexity

The complexity of the labeling task escalates with the addition of more sensors. Each sensor has unique characteristics and requires specific annotation techniques to capture relevant information accurately. Coordinating and synchronizing data from different sensors to generate coherent annotations becomes increasingly challenging as the number of sensors involved grows.

Ensuring Consistency

Ensuring consistency and accuracy in labeling becomes more difficult as the scale expands. Maintaining high-quality annotations across a large dataset becomes a complex endeavor, as it requires effective quality control mechanisms and strict adherence to labeling standards.

Limited Flexibility in Automated Labeling

Automated labeling methods offer less flexibility when dealing with the intricacies and nuances of different sensor modalities and their fusion. This process poses challenges in accurately handling the unique characteristics of each sensor.

Tackling Edge Cases

Handling complex and uncommon scenarios, known as edge cases, presents a significant challenge in multi-sensor fusion labeling. To successfully address these cases, you require innovative approaches and robust algorithms to ensure reliable and accurate data fusion.

Evolving Sensor Technologies

As new sensors and modalities are introduced, the labeling process must be flexible enough to handle these advancements. It will require staying up-to-date with the latest sensor technologies, understanding their capabilities and limitations, and adjusting labeling approaches accordingly.

Overcoming Data Labeling Challenges with iMerit

iMerit has 10+ years of experience in multi-sensor annotation for the camera, LiDAR, radar, and audio data to enhance scene perception, localization, mapping, and trajectory optimization. Here is a sneak peek at how iMerit’s human-in-the-loop model overcomes all the mentioned data challenges by combining the right technology, talent, and technique.

Custom Workflows for High Accuracy and Flexibility

iMerit’s human-in-the-loop model addresses the challenges of multi-sensor fusion labeling by employing custom workflows tailored to specific requirements. These workflows ensure high accuracy in data labeling while offering flexibility to accommodate diverse sensor modalities and fusion techniques. By designing workflows that align with the unique characteristics of each project, iMerit optimizes the labeling process for optimal results.

Specialized Workforce to Handle Edge Cases

To tackle the challenges of data complexity, variability, and scalability, iMerit has a specialized workforce of over 2500 members in the autonomous vehicle domain with curriculum-driven training for quality at scale. This team has experience in complex scenarios and edge cases that may arise during multi-sensor fusion labeling. 

Tool-agnostic Approach 

iMerit adopts a tool-agnostic approach, allowing for seamless integration with various annotation tools. In case of specific requirements, we train our teams to work on the client’s proprietary tools. Alternatively, we have in-house annotation solutions and partnerships with the top 3rd party annotation tools, including,,, and

Effective Quality Control 

iMerit prioritizes effective quality control in multi-sensor fusion labeling by implementing real-time reporting mechanisms. It enables constant monitoring of the labeling process, ensuring adherence to quality standards and swift identification and resolution of any issues or inconsistencies.

Experience with Leading Autonomous Vehicle Companies

iMerit has extensive experience collaborating with the top three out of five leading Autonomous Vehicle companies. This firsthand experience provides our team with valuable insights into the unique challenges and requirements of the industry. By leveraging this experience, we can tailor its solutions to meet the specific needs of autonomous vehicle projects, ensuring the highest quality and accuracy in multi-sensor fusion labeling.


Multi-sensor fusion in autonomous vehicles presents unique challenges that require robust data labeling and annotation solutions. With the right expertise and technology, these challenges can be overcome to drive advancements in autonomous driving technology.

At iMerit, we provide comprehensive data labeling and annotation services for 3D sensor fusion in autonomous vehicles. Our experienced team of over 5500 members, custom workflows, and tool-agnostic approach ensures high accuracy and flexibility in handling diverse sensor data. 

With a track record of successfully annotating over 250 million data points for the autonomous vehicle sector, we are a trusted partner in delivering reliable and precise multi-sensor fusion annotations.

Are you looking for data experts to advance your sensor fusion project? Here is how iMerit can help.