Overview
ISO/TS 19124-2:2025 - Geographic information - Calibration and validation of remote sensing data and derived products - Part 2: Synthetic aperture radar (SAR) - defines standardized procedures for calibrating and validating Earth observation (EO) data acquired by SAR sensors and products derived from SAR. The specification covers general and advanced SAR working modes, metadata needed for calibration/validation, and evaluation criteria to ensure SAR data and SAR-derived products are interoperable and fit for quantitative and qualitative use. It explicitly does not replace sensor-hardware calibration (see ISO/TS 19159-3).
Key topics and technical requirements
- Calibration scope: geometric correction, radiometric calibration/correction, and calibration of characteristic parameters for both qualitative and quantitative applications.
- Validation scope: evaluation of calibrated data and derived products against quality metrics and accuracy requirements.
- SAR data characteristics: definitions and requirements for general working modes and multi-dimensional modes (multi-polarimetric, multi-aspect, multi-temporal, multi-frequency).
- Quality metrics: resolution and swath width, imaging quality (e.g., azimuth ambiguity, ISLR), geometric accuracy, and radiometric accuracy.
- SAR-derived products: classification of geophysical products (numerical, categorical, multi-dimensional) and their specific validation considerations.
- Metadata and conformance: metadata elements related to calibration/validation that are not defined elsewhere; conformance criteria and reference abstract test suite.
- Supporting content: normative annexes such as an abstract test suite and data dictionary; informative annexes with examples (imagery level definitions, 3D SAR products, multi-polarimetric data).
Applications and who uses it
ISO/TS 19124-2:2025 is intended for:
- Satellite operators and mission teams implementing SAR data processing chains.
- Remote sensing data processors and software vendors delivering calibrated SAR imagery and value-added products.
- GIS and EO analysts who integrate multi-source SAR data for applications like disaster monitoring, geological mapping, land cover classification, and environmental monitoring.
- Validation laboratories and national mapping agencies performing quality assurance and interoperability testing.
- Researchers and standards bodies developing methods for SAR product generation and assessment.
Practical benefits include consistent radiometric/geometric corrections, comparable cross-sensor products, clear metadata for QA, and standardized validation workflows to support operational decision-making.
Related standards
- ISO/TS 19124-1 - Fundamentals of calibration and validation for remote sensing data.
- ISO/TS 19159-3 - Calibration and validation of SAR/InSAR sensors (hardware-level sensor calibration; complementary to ISO/TS 19124-2).
Keywords: ISO/TS 19124-2:2025, SAR calibration, SAR validation, synthetic aperture radar, remote sensing, EO data, radiometric calibration, geometric correction, SAR-derived products, multi-polarimetric SAR.