Review of Literature on Intercomparison Studies Between GPM DPR and Ground-Based Radars

Intercomparison studies between satellite-based and ground-based radar systems are essential for advancing radar technologies and improving precipitation retrieval algorithms. This study conducted a systematic literature review of Global Precipitation Measurement Mission (GPM) Dual-Frequency Precipitation Radar (DPR) and ground-based radar intercomparison studies using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) method, focusing on peer-reviewed literature published between 2014 and 2024. The review synthesizes current knowledge of DPR precipitation detection and estimation, including the application of DPR in ground-based radar calibration, and discussions on retrieval methods and attenuation correction algorithms. Most studies used a volume-matching method to compare observations between datasets and examine S- and C-band radars from national networks. Most analyses occurred over the Northern Hemisphere, and individual ground-based radars were more frequently compared to DPR rather than examining mosaics. Beyond summarizing existing studies, this review identifies systematic, geographic, methodological, and algorithmic gaps that constrain comprehensive validation of DPR products. Recurrent bias patterns—such as precipitation-type-dependent errors and attenuation-related uncertainties—highlight priority areas for algorithm refinement and targeted validation campaigns. By synthesizing validation strategies and recurring performance limitations, this work provides a structured reference for future intercomparison studies, supports more standardized validation practices, and informs the development of improved precipitation retrieval algorithms, ground-based radar calibration practices, and next-generation satellite radar missions.