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=ASIA6AP2G7AKBNQ7ZJNT%2F20251227%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251227T105258Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEKD%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaDGV1LWNlbnRyYWwtMSJIMEYCIQD8uJa7AHyNQXg66mFoRDeOkRQ71%2BuIfZLLfB%2F6F7Dd4AIhAPa2dpeSET0%2Bv3jJ4EGJOURKJm%2FOdCIHlqclDatDUc1FKrwFCGkQAhoMOTYzMTM0Mjg5OTQwIgxEKGQJWgvJWpFYTb4qmQVvKl97lCGmmP7VMLED%2F5V140YQfNoLFw%2F9We%2Bv455Rhgc1gIyDaQhdyMj1glSnUAweoSaaJzrkrZ9PUIKmGc6Dsk39wryMT7G4UqMovdF7tq667ao5pO4t69WCJnPwzLcVZTT8c%2F7x%2FdClsx50U%2BGpdJhdNsCWNS2K6cTrjNzASZifYw2V8rWJ7LkJyGi9oGDypDK5a%2Fneu33gWlMaNeSqD%2FIpjkCZdX3tWaKBuoD%2B%2Bim9dhNqGjUanF7l6QlNS2Evra%2FI64QDmOgp3LUyA60QviDyvNOMTKqclvnCAMewlYikBosvB%2FGAD8xNUpqNCYqLjKGH48GL0PdVdOBQOyHwCATROLXLMJBuRwD3Q6beBOSKWQh2fLQ2BXzptYD%2B4o2G9SNVxo341iAydD6s2ejJTs6xls58WBm87t0BtUPP6AXL7%2BDaSeiMMl%2B1lL8rDFXL1Su3L%2BHoKwqUpY7zhf%2FuXAFrdftxotxZz2z1rLYUcpHWzRcAmqbrk5jF4DMuxzroks10bBxl1MNqhFr6FTs8Wrypc2JBk1QLpC%2Fu%2FIvMC8qh%2FdsmYQXeJf%2B0z9IyAouWuwX9k2aZyibFiOA5eNkjmNKuw6xm8okau92bSipVYtdvL11o9Vjg8pBFh7vZZ3APLUS6QG6LsAI9G99YyUGP9OCeLFNEcfI3k4%2Bco2XptjmDhQQBJsNzhDtgV8bQDLwtNkSODukax11J1iL9kO64rTue30cGFxZbY%2FFz46t3zTDmNMsC84Fk7TCxVRL6rU4SpGuPXpIw6qjF3l%2FZBSDk7JBZaoEDyeOZtvtsEmYf%2Bqc2Xnaw7mHgM05iJHPQcWXlCIClkIb8ENrCDA3JkPUFym8kHN9GKSn%2F%2BH8lU8NjUAKaYulms0AiHzDhor7KBjqwASFsnJVFwOqEJLz27mRj43SB059orKQhcnyVp4vRW2nxYRLNw0T5ighzmebBN8lRzlsKJDTUXaTu2Y1paJ5C5FBrGieOMDbIUtIBI16nHz0%2FI1VoK8J8UYc%2Bija%2BuhebBvE7V7OrwskIHi2reNCA%2FzRUD5pGamhBaMmuBDLpt9epr0pF7yo74ut%2BwiIIvAgCO60kBIvP5SjHNzv51OjepaHT9ijzpn2asKYk3NroTekn&X-Amz-Signature=441ccf9dadca96e19a2b04997466d3c79d3a344b57a469e44ce0af06ffc9c647&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=ASIA6AP2G7AKBNQ7ZJNT%2F20251227%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251227T105258Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEKD%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaDGV1LWNlbnRyYWwtMSJIMEYCIQD8uJa7AHyNQXg66mFoRDeOkRQ71%2BuIfZLLfB%2F6F7Dd4AIhAPa2dpeSET0%2Bv3jJ4EGJOURKJm%2FOdCIHlqclDatDUc1FKrwFCGkQAhoMOTYzMTM0Mjg5OTQwIgxEKGQJWgvJWpFYTb4qmQVvKl97lCGmmP7VMLED%2F5V140YQfNoLFw%2F9We%2Bv455Rhgc1gIyDaQhdyMj1glSnUAweoSaaJzrkrZ9PUIKmGc6Dsk39wryMT7G4UqMovdF7tq667ao5pO4t69WCJnPwzLcVZTT8c%2F7x%2FdClsx50U%2BGpdJhdNsCWNS2K6cTrjNzASZifYw2V8rWJ7LkJyGi9oGDypDK5a%2Fneu33gWlMaNeSqD%2FIpjkCZdX3tWaKBuoD%2B%2Bim9dhNqGjUanF7l6QlNS2Evra%2FI64QDmOgp3LUyA60QviDyvNOMTKqclvnCAMewlYikBosvB%2FGAD8xNUpqNCYqLjKGH48GL0PdVdOBQOyHwCATROLXLMJBuRwD3Q6beBOSKWQh2fLQ2BXzptYD%2B4o2G9SNVxo341iAydD6s2ejJTs6xls58WBm87t0BtUPP6AXL7%2BDaSeiMMl%2B1lL8rDFXL1Su3L%2BHoKwqUpY7zhf%2FuXAFrdftxotxZz2z1rLYUcpHWzRcAmqbrk5jF4DMuxzroks10bBxl1MNqhFr6FTs8Wrypc2JBk1QLpC%2Fu%2FIvMC8qh%2FdsmYQXeJf%2B0z9IyAouWuwX9k2aZyibFiOA5eNkjmNKuw6xm8okau92bSipVYtdvL11o9Vjg8pBFh7vZZ3APLUS6QG6LsAI9G99YyUGP9OCeLFNEcfI3k4%2Bco2XptjmDhQQBJsNzhDtgV8bQDLwtNkSODukax11J1iL9kO64rTue30cGFxZbY%2FFz46t3zTDmNMsC84Fk7TCxVRL6rU4SpGuPXpIw6qjF3l%2FZBSDk7JBZaoEDyeOZtvtsEmYf%2Bqc2Xnaw7mHgM05iJHPQcWXlCIClkIb8ENrCDA3JkPUFym8kHN9GKSn%2F%2BH8lU8NjUAKaYulms0AiHzDhor7KBjqwASFsnJVFwOqEJLz27mRj43SB059orKQhcnyVp4vRW2nxYRLNw0T5ighzmebBN8lRzlsKJDTUXaTu2Y1paJ5C5FBrGieOMDbIUtIBI16nHz0%2FI1VoK8J8UYc%2Bija%2BuhebBvE7V7OrwskIHi2reNCA%2FzRUD5pGamhBaMmuBDLpt9epr0pF7yo74ut%2BwiIIvAgCO60kBIvP5SjHNzv51OjepaHT9ijzpn2asKYk3NroTekn&X-Amz-Signature=cc601d010744767252aab89f848438a568efc54d0dd1fc5c2383a568c1564e3f&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 |