Selection of Potential Pseudoinvariant Calibration Sites in Australia Based on Pixel-Level Cloud Cover and Rainfall Probabilities

Significant work has been done to select on pseudoinvariant calibration sites (PICSs) over the past 20 years. However, regional cloud cover and rainfall factors were not fully considered in previous PICS selection work. Australia has large arid areas where PCIS are not fully explored. This article proposed a novel method for selecting potential PICSs in Australia by utilizing cloud cover and rainfall probabilities. MOD09GA, and Global Satellite Mapping of Precipitation products from 2016 to 2022, along with the Smoothed Digital Elevation Model are utilized to identify flat areas with minimal cloud cover and rainfall. Coefficient of variation $< $ 0.03 and Geits statistics (Gi$^{\ast }$) $>$ 0 based on MOD09GA, Landsat Operational Land Imager (OLI), and Sentinel MultiSpectral Instrument (MSI) are used to characterize potential PICSs. Finally, we identified three potential PICSs, namely, PICS1 (0.51 km$^{2}$), PICS2 (0.35 km$^{2}$), and PICS3 (0.23 km$^{2}$), with annual probability of cloud- or rainfall-free exceed 80% . The feasibility of using these three PICSs for radiometric performance monitoring of satellites sensors were also verified. Results indicate that the selected PICSs were effective since the sensor annual degradation rates (% /year ${\pm }$ 2-sigma) of OLI and MSI over the selected PICSs range from −0.68% ${\pm }$0.35 to 0.57% ${\pm }$0.43, which are consistent with LCFR (from −0.48% ${\pm }$0.35 to 0.28% ${\pm }$0.71), except for Red band. The proposed method extends the PICS network in Australia, and introduces new ideas for potential PICS selection.