Fig. 1.
![Description of notation and angles [4].](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/690506c6ec0c762251660350/j_msr-2025-0044_fig_001.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=ASIA6AP2G7AKBIEER2XZ%2F20260221%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20260221T234813Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEO%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaDGV1LWNlbnRyYWwtMSJIMEYCIQDgj7HYiKGyGNVjpodPpBxOiFjpaQHC0sOSGNnfJTOjIwIhAKIvBhGB8PP9OJqC63ApeBBIaj7KH7W8xlyyVa9Z%2B1n3KsUFCLj%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEQAhoMOTYzMTM0Mjg5OTQwIgyN8mRYGQHuNODbSJEqmQUKQoW4inPfiH6hO2OVCWVLpWPsXamHfLeKLxJT7aBGKI%2BIjdPyfBjkS1A0N0Di8thRQi44kq7WTs4pOgUG74HQ8ClfhwX0Aga3X1pMk3fr7tNbato5aSi8i%2Bh4Bepn8v6sAW16Dm60aQpgxzA1WUlzHK%2FjN2G71zDnA05sCXhATn3e%2FSd0LgMPFXMm1PvJgvNooiAQTVZp4ZnRlNx7U5tWE2QjE6rw%2BoftGeCShcg%2BJQvF8cJlX8a0nHUq1bvwpJFlRGmHcI%2Bqqc3fkSNdsvE%2BIrPKMZ3mtrRZDur2pYA749IuGtxBGcTQEcZ8oaY1KkMeEIYspox6f%2BRyO5RKW8PAhVDeTxqXizluoE%2BImCy0oQa1VHctt5ME6o7u%2Ff7abtvZQbYywzMKkiLmKfQjeBXvkpW39dcinP%2B7B26tElpDUzGLA0T73Y0g%2FXvexOC%2F7ytDOCbtpqz1Py8Up%2FNACf%2FqJZz3WxUsigBijwT29HcSdqDbTzBzWVx4l1j6Kzz8jOPMvKCpaC006E1%2Fu8H6N5NCFQgMrvVBdZSfiGEk1cT8ZFqajltDKF8POpzKAQUC7P2V15f7dPC%2Bu8sL0A%2BEIIlRSyRKSEE6xmheF6slpRu7pCO%2BLvK2q3YPhG%2F2mFcP6KwO2Gxp7xQ9ZmDTJLeMqVOR4POkHmYgsy1R3dJMLmJPcej9xowNJQQV2Y7KrDAfXfbwjkVzAcRWI51jfLCjXd5q8bkuJ3%2BcW3iMJ8mmkqYs6%2FoH6eUB7RG1NH2gGmU2tQu3Np8p%2BOTFb3sf2vG3RJsZn2U7%2BeIoT%2BAuM5BkaIGRwR%2BYwX6sKCO9RfzNQG50yj2Fb4P%2B9JEm2cuESJcAgk8ldBtsmwZ4ZOvE5fLga3OAJrOol2YtAxngDTDi7%2BjMBjqwAWuVm%2FjoHcMXivscVrJoaemE4b%2FH7ZMG02fQI8cYegAWS9dQJGfN%2F05zxm2BezlWkG3GJWOqRoiPVgTVSI9zp6n%2BCUB52X3o4J9RbRbMpaLG4%2FpDkwbLy3UoAXABT7tshjJzdURLVhUyTWqTMKMWmm%2FBF9hDMT5LUZiK9LSyRWOYa0otlHpPrB6DO5s5vebfo7Dk3R28x7jw2lMSmqaTQJBqMPXdJYcWKCtRreKmJ0oq&X-Amz-Signature=ca6bd305863919472a85b579a55a2db5da718d46819aab0985ed31ec4fb86eeb&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Fig. 2.
Fig. 3.
![Diagram of the RoboCapp detection system [6].](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/690506c6ec0c762251660350/j_msr-2025-0044_fig_003.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=ASIA6AP2G7AKBIEER2XZ%2F20260221%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20260221T234813Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEO%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaDGV1LWNlbnRyYWwtMSJIMEYCIQDgj7HYiKGyGNVjpodPpBxOiFjpaQHC0sOSGNnfJTOjIwIhAKIvBhGB8PP9OJqC63ApeBBIaj7KH7W8xlyyVa9Z%2B1n3KsUFCLj%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEQAhoMOTYzMTM0Mjg5OTQwIgyN8mRYGQHuNODbSJEqmQUKQoW4inPfiH6hO2OVCWVLpWPsXamHfLeKLxJT7aBGKI%2BIjdPyfBjkS1A0N0Di8thRQi44kq7WTs4pOgUG74HQ8ClfhwX0Aga3X1pMk3fr7tNbato5aSi8i%2Bh4Bepn8v6sAW16Dm60aQpgxzA1WUlzHK%2FjN2G71zDnA05sCXhATn3e%2FSd0LgMPFXMm1PvJgvNooiAQTVZp4ZnRlNx7U5tWE2QjE6rw%2BoftGeCShcg%2BJQvF8cJlX8a0nHUq1bvwpJFlRGmHcI%2Bqqc3fkSNdsvE%2BIrPKMZ3mtrRZDur2pYA749IuGtxBGcTQEcZ8oaY1KkMeEIYspox6f%2BRyO5RKW8PAhVDeTxqXizluoE%2BImCy0oQa1VHctt5ME6o7u%2Ff7abtvZQbYywzMKkiLmKfQjeBXvkpW39dcinP%2B7B26tElpDUzGLA0T73Y0g%2FXvexOC%2F7ytDOCbtpqz1Py8Up%2FNACf%2FqJZz3WxUsigBijwT29HcSdqDbTzBzWVx4l1j6Kzz8jOPMvKCpaC006E1%2Fu8H6N5NCFQgMrvVBdZSfiGEk1cT8ZFqajltDKF8POpzKAQUC7P2V15f7dPC%2Bu8sL0A%2BEIIlRSyRKSEE6xmheF6slpRu7pCO%2BLvK2q3YPhG%2F2mFcP6KwO2Gxp7xQ9ZmDTJLeMqVOR4POkHmYgsy1R3dJMLmJPcej9xowNJQQV2Y7KrDAfXfbwjkVzAcRWI51jfLCjXd5q8bkuJ3%2BcW3iMJ8mmkqYs6%2FoH6eUB7RG1NH2gGmU2tQu3Np8p%2BOTFb3sf2vG3RJsZn2U7%2BeIoT%2BAuM5BkaIGRwR%2BYwX6sKCO9RfzNQG50yj2Fb4P%2B9JEm2cuESJcAgk8ldBtsmwZ4ZOvE5fLga3OAJrOol2YtAxngDTDi7%2BjMBjqwAWuVm%2FjoHcMXivscVrJoaemE4b%2FH7ZMG02fQI8cYegAWS9dQJGfN%2F05zxm2BezlWkG3GJWOqRoiPVgTVSI9zp6n%2BCUB52X3o4J9RbRbMpaLG4%2FpDkwbLy3UoAXABT7tshjJzdURLVhUyTWqTMKMWmm%2FBF9hDMT5LUZiK9LSyRWOYa0otlHpPrB6DO5s5vebfo7Dk3R28x7jw2lMSmqaTQJBqMPXdJYcWKCtRreKmJ0oq&X-Amz-Signature=3ca520e7219c1bddf99b135b9f76e42d92ff67ae1ddeac94d17d78a73b0e4abb&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Fig. 4.
Uncertainty budget_
| Individual input parameter | Uncertainty contribution to the spectral radiance factor measured value | The individual factors can be assessed as follows: |
|---|---|---|
| Uncertainty in angles / Cosine of θi / Zenith angle / Axis alignment | 1.34E-06 | This value is very small, indicating that the angles and axis alignment have a minimal effect on the overall measurement uncertainty. Therefore, this contribution is negligible. |
| Aperture + Sample-to-detector distance | 8.54E-03 | This factor contributes the most to the total uncertainty. The distance and geometry of the sample can significantly affect the measurement, which is reflected in the relatively high uncertainty value. |
| Detector uniformity / Linearity | 2.03E-03 | This is a significant factor, but smaller than the geometric aspects. Although the linearity of the detector may influence the measurement, it contributes moderately to the total uncertainty. |
| Noise / Reading of signal | 3.54E-03 | This factor also contributes a relatively high portion to the total uncertainty, suggesting that the signal is susceptible to noise, which could compromise the accuracy of the measurements. |
| View factor / Illuminated area | 1.67E-04 | This contribution is very small, indicating that the view factor and illuminated area have only a minimal impact on the measurement uncertainty. |
| Instability of the light source | 2.31E-03 | This uncertainty is significant because the stability of the light source can affect the measurement intensity, and consequently, the results. |
| Wavelength | 8.11E-04 | This contribution is very small and can be considered negligible in the context of the overall uncertainty. |
| Reproducibility | 3.32E-03 | This factor has a relatively high impact on the measurement results, suggesting some variability between individual measurements [9], [10]. |
| Total uncertainty | 1.03E-02 |