How do you assess the accuracy and reliability of remote sensing-derived vegetation indices?

Sample interview questions: How do you assess the accuracy and reliability of remote sensing-derived vegetation indices?

Sample answer:

Accuracy Assessment

Field measurements: Collect vegetation data in the field and compare it to indices derived from remote sensing data.
Reference data: Utilize high-resolution aerial or satellite imagery or maps to evaluate the correspondence between indices and vegetation density or biomass.
Error matrices: Calculate error metrics such as user’s accuracy, producer’s accuracy, and overall accuracy to quantify the agreement between the index and the reference data.
Validation protocols: Adhere to standardized validation protocols, such as the Remote Sensing Accuracy Assessment Working Group (RSAAWG), to ensure consistency and comparability.

Reliability Assessment

Temporal stability: Assess the consistency of indices over time by comparing them from multiple dates or under different conditions.
Noise considerations: Evaluate the sensitivity of indices to factors such as atmospheric conditions, sensor noise, and data preprocessing methods.