Effect of the instrument slit function on upwelling radiance from a wavelength dependent surface reflectance

TL;DR

This study investigates how the instrument slit function influences upwelling radiance measurements from surface reflectance, demonstrating a good match between canopy coverage and radiance proportions, which supports improved remote sensing analysis.

Contribution

It provides a novel analysis of the instrument slit function's impact on radiance measurements, enhancing the accuracy of surface reflectance retrievals in remote sensing.

Findings

Good match between canopy coverage and radiance proportions

Instrument slit function significantly affects radiance measurements

Supports improved remote sensing surface reflectance analysis

Abstract

The Radiance Enhancement (RE) method was introduced for efficient detection of clouds from the space. Recently, we have also reported that due to high reflectance of combustion-originated smokes, this approach can also be generalized for detection of the forest fires by retrieving and analyzing datasets collected from a space orbiting micro-spectrometer operating in the near infrared spectral range. In our previous publication, we have performed a comparison of observed and synthetic radiance spectra by developing a method for computation of surface reflectance consisting of different canopies by weighted sum based on their areal coverage. However, this approach should be justified by a method based on corresponding proportions of the upwelling radiance. The results of computations we performed in this study reveal a good match between areal coverage of canopies and the corresponding proportions of the upwelling radiance due to effect of the instrument slit function.