Impact of the cameras radiometric resolution on the accuracy of determining spectral reflectance coefficients

Abstract

ABSTRACT:Nowadays remote sensing plays a very important role in many different study fields, i.e. environmental studies, hydrology, mineralogy, ecosystem studies, etc. One of the key areas of remote sensing applications is water quality monitoring. Understanding and monitoring of the water quality parameters and detecting different water contaminants is an important issue in water management and protection of whole environment and especially the water ecosystem. There are many remote sensing methods to monitor water quality and detect water pollutants. One of the most widely used method for substance detection with remote sensing techniques is based on usage of spectral reflectance coefficients. They are usually acquired using discrete methods such as spectrometric measurements. These however can be very time consuming, therefore image-based methods are used more and more often. In order to work out the proper methodology of obtaining spectral reflectance coefficients from hyperspectral and multispectral images, it is necessary to verify the impact of cameras radiometric resolution on the accuracy of determination of them. This paper presents laboratory experiments that were conducted using two monochromatic XEVA video sensors (400-1700nm spectral data registration) with two different radiometric resolutions (12 and 14 bits). In view of determining spectral characteristics from images, the research team used set of interferometric filters. All data collected with multispectral digital video cameras were compared with spectral reflectance coefficients obtained with spectroradiometer. The objective of this research is to find the impact of cameras radiometric resolution on reflectance values in chosen wavelength. The main topic of this study is the analysis of accuracy of spectral coefficients from sensors with different radiometric resolution. By comparing values collected from images acquired with XEVA sensors and with the curves obtained with spectroradiometer it's possible to determine accuracy of imagebased spectral reflectance coefficients and decide which sensor will be more accurate to determine them for protection of water aquatic environment purpose.

Improvement of 3D Power Line Extraction from Multiple Low-Cost UAV Imagery Using Wavelet Analysis

“…In their paper [11], Oh and Lee used horizontal-extended filters to constrain noise and enhance power lines in the image. A similar approach to correcting the digital images and thus improving the resulting quality was confirmed in such publications as [16,17], where the grey ratio operator and mathematical morphology, among others, were used to refine power line feature extraction.…”

Portable Imagery Quality Assessment Test Field for Uav Sensors

“…Every time an image is acquired on film or by a detector, its sensitivity to the magnitude of the electromagnetic energy determines the radiometric resolution. The radiometric resolution can be defined as the sensitivity of a sensor to incoming flux (Levin, 1999;Orych et al, 2014). The second segment if the PIQuAT is built from three parts, that together form a 12-level greyscale board (from black-3% reflectance to white-85% reflectance).…”

Methodology for Determining Optimal Exposure Parameters of a Hyperspectral Scanning Sensor

“…the exposure time or the gain value. Along with greater values of exposure parameters it is possible to obtain greater range of DN valuesthe radiometric range is greater, therefore the interpretation capacity of such image is greater (Orych et al, 2014).…”