COMPARING RADIATIVE TRANSFER EQUATION METHOD (RTEM) AND THE GENERALIZED SINGLE-CHANNEL METHOD (GSCM)FOR RETRIEVING SEA SURFACE TEMPERATURE ALONG THE KARACHI COAST, PAKISTAN

Abstract

The monitoring of sea surface temperature (SST) is crucial for understanding the impact of various processes in aquatic ecosystems. The coastal waters of Karachi, Pakistan are particularly affected by pollution from industries and power plants. To effectively monitor and detect changes in SST, satellite remote sensing has been proposed as an efficient and cost-effective method. This study compares the performance of two methods for estimating SST, the Radiative Transfer Equation Method (RTEM) and the Generalized Single-Channel Method (GSCM). Correlation and linear regression models were applied to analyze trends, and a one-way ANOVA was also computed using Landsat ETM+ thermal infrared data. SST estimates were obtained at 14 different locations using in-situ data and a simple regression technique. The results indicate that both methods have a highly significant relationship with in-situ measurements, with the coefficient of determination (R2) of 0.51 for RTEM and 0.80 for GSCM, respectively. Both methods also have acceptable standard errors, with GSCM having an RMS of 1.50 and RTEM having an RMS of 2.40. In general, both approaches show a strong statistical trend when using real-ground data.