Introducing Check & Adjust feature for the Leica RTC360

When capturing reality with Leica Geosystems’ 3D laser scanning solutions, the accuracy and reliability of your measuring equipment should always have the highest priority. That is why we have introduced the new Check & Adjust feature for the Leica RTC360 3D laser scanner. Checking and improving the angular accuracy of your RTC360 directly in the field is now quicker and easier than ever before.

Leica Geosystems 3D laser scanners are manufactured, assembled, adjusted and calibrated to the highest standard. However, extreme temperature changes, harsh conditions and hard shocks can cause deviations and influence the system’s accuracy over time. It is important that laser scanners, like any other optical-mechanical measuring devices which are exposed to such harsh conditions, are checked periodically to ensure the measurement results meet the manufacturing specifications. This periodic check can be easily completed by the user in the field by running through a short and specific Check & Adjust procedure.

What is Check & Adjust?
Check & Adjust procedure is a quick, smart and user-friendly solution, which allows the user to:

1. Check the current angular accuracy of the RTC360
2. Adjust the angular parameters to improve the angular accuracy of the RTC360 directly in the field

A similar feature is already available for the Leica ScanStation P30/P40 and P50 high-end laser scanners, however the Check & Adjust procedure for RTC360 is different by its approach, speed and ease-of-use.

What is unique about Check & Adjust for RTC360?
Check & Adjust is a fully automated, straightforward, one-button, procedure which is easily completed in the field, in less than 6 minutes. It does not require a specific measurement field containing a prescribed configuration of targets, as with other similar solutions on the market today. This makes the feature appealing for users, as the procedure can be carried out directly at the job site in a short period time, without extensive effort or interaction from the user, such as preparing the measurement field, installing the targets and aiming at the targets.

How does Check & Adjust work?
The procedure is fully automated and only requires a double scan at one position to calculate the new angular parameters and angular accuracy of the scanner. The feature itself uses the point-normal based approach of the in-field self-calibration which parametrises deviations between two face measurements in the object space to the internal instrumental deviations, and further to the angular calibration parameters according to the functional calibration model of the scanner. Adjustment of the angular calibration parameters is performed by minimising the deviations between selected core points in both faces using an optimisation function. Suitable core points are selected by the highest confidence weight, which is calculated for each measured point based on distance, elevation angle, residuals of plane fit, point intensity, normal deviation and angle of incidence. The surrounding environment has an important role for this procedure, as measured points of the scene are the only input to the algorithm. Therefore, it is essential that the location of the scan is carefully selected according to the Check & Adjust guidelines in the user manual. Prior to the calculation of the new calibration parameters, the suitability of the environment is automatically checked by the system. When the environment classification meets the requirements, current and adjusted angular accuracy of the scanner is calculated together with new angular calibration parameters, which can be applied in order to improve the angular accuracy of the scanner. When the user applies the new angular calibration parameters, they are permanently stored in the instrument and automatically applied to all subsequent measurements. The angular calibration parameters can be reset to the in-factory calibration values at any time. For each completed Check & Adjust procedure, a PDF report, containing Check & Adjust information, is automatically generated and stored to the USB stick.

Why is Check & Adjust beneficial?
The ability to perform Check & Adjust without the need for a special measurement field is a significant advantage for users who frequently transport the scanner to long distance locations. Imagine shipping your scanner by aeroplane from Europe to Australia for an upcoming project - you never really know if the luggage was handled carefully throughout the duration of its journey. The same precaution should be taken with rugged handling at the work site or exposure to extreme environmental conditions. After the exposure of the scanner to such unfavourable conditions, the user can check whether the angular accuracy of RTC360 is still within specification and can improve the angular accuracy, without sending it for inspection and in-factory calibration to a certified Leica Geosystems service centre. Scanning downtime is therefore vastly reduced, significantly boosting productivity on site and at the same time, confidence in the consistency of the scan data accuracy is gained, quickly and effortlessly.

To ensure the best possible scan data quality and to consistently deliver the best results, it is essential to be confident about your measuring equipment no matter what it has been put through. The specified accuracy of the RTC360 can be easily maintained by frequently performing the Check & Adjust procedure, keeping it in optimal working condition.

Check & Adjust feature for the RTC360 was released in firmware version 3.0. You can download the latest firmware version from Leica Geosystems’ myWorld customer portal.