Spatio-Temporal Assessment of Tuz Gölü, Turkey as a Potential Radiometric Vicarious Calibration Site

Vincent Odongo,Edward Milton,Nicholas Hamm

doi:10.3390/rs6032494

Abstract

The paper provides an assessment of Tuz Gölü, a site in Turkey proposed for the radiometric vicarious calibration of satellite sensors, in terms of its spatial homogeneity as expressed in visible and near-infrared (VNIR) wavelengths over a 25-year period (1984–2009). By combining the coefficient of variation (CV) and Getis statistic (Gi*), a spatially homogenous and temporally stable area at least 720 m × 330 m in size was identified. Analysis of mid-summer Landsat Thematic Mapper (TM) images acquired over the period 1984–2009 showed that the hemispherical-directional reflectance factor of this area had a spatial variability, as defined by the CV, in the range of 0.99% to 3.99% in Landsat TM bands 2–4. This is comparable with the reported variability of other test sites around the world, but this is the first time an area has been shown to have this degree of homogeneity over such a long period of time.

Highlights

Accurate satellite sensor calibration is vital if data products derived from Earth observation (EO)
This paper presents an independent evaluation of Tuz Gölü as a Vicarious calibration (VC) site, with an emphasis on its long-term spatial homogeneity
Thematic Mapper (TM) by [23] explain that the accuracy was in the order of 5% during pre-launch and post-launch, assessed through on-board and vicarious calibration

Summary

Introduction

Accurate satellite sensor calibration is vital if data products derived from Earth observation (EO). Are to be reliable sources of data for decision support systems in environmental management. This is especially important in studies involving monitoring change over time or combining data from. Radiometric sensor calibration, maintaining that calibration over the lifetime of the system, and the provision of traceability to international standards are all vital steps to ensure confidence in EO data products [2,3]. Vicarious calibration (VC) using ground targets has become established as an important method of post-launch radiometric calibration, and the Committee on Earth. Observation Satellites (CEOS) Working Group on Calibration and Validation (WGCV) has endorsed eight terrestrial sites for the post-launch calibration of space-based optical imaging sensors, including. Dry lake beds and sandy desert areas are most commonly chosen as VC sites [6,7,8]

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Methods

Conclusion