Design and performance analysis of a broadband surface reflectance measurement system for unattended field applications

Abstract

Surface reflectance is a key reference for remote-sensing radiometric calibration and quantitative product validation. Manual spectrometer measurements suffer from temporal mismatch, operator-dependent uncertainty, and high labor cost, which limits long-term field use. This paper presents an unattended broadband surface reflectance measurement system covering 350-1700 nm. The system integrates dual-spectrometer observation, automatic white-panel switching, environmental sensing, local storage, and 4G communication. The optical path, viewing geometry, field-of-view consistency, sampling interval, integration-time control, panel actuation, power management, and weatherproof enclosure are designed for repeatable outdoor operation. A panel-based radiometric calibration procedure, overlap-region response matching, smooth-transition fusion, and temperature-coupled denoising model are introduced to improve calibration traceability, spectral continuity, and stability. Field tests show stable automated operation, improved continuity in the 900- 1000 nm overlap region, and repeatability enhanced from about 5% to 1%.