The Indian Space Research Organisation (ISRO) has announced the release of advanced radar-derived data products from its Chandrayaan-2 Orbiter, offering unprecedented insight into the Moon’s scarcely explored polar regions. Using the Dual-Frequency Synthetic Aperture Radar (DFSAR) instrument, scientists have generated detailed polarimetric mosaics of the lunar north and south poles, paving the way for deeper understanding of the Moon’s surface and subsurface properties.
At the heart of this achievement is the DFSAR payload aboard the Chandrayaan-2 orbiter, which has been operating in lunar orbit since 2019. The instrument specialises in L-band full-polarimetric synthetic aperture radar imaging, achieving a spatial resolution of approximately 25 metres per pixel—the first of its kind for lunar mapping. Over the mission lifetime, roughly 1,400 radar datasets have been acquired and processed to generate comprehensive polar mosaics of both the 80° to 90° latitude zones in the Moon’s northern and southern hemispheres.
These newly released “Level 3C” data products include key radar-derived parameters such as the Circular Polarisation Ratio (CPR), which helps detect the presence of water-ice in permanently shadowed or highly reflective regions; the Single Bounce Eigenvalue Relative Difference (SERD), which provides insights into surface roughness and scattering behaviour; and the T-Ratio, which relates to the dielectric constant of lunar material and reveals details about density, porosity and subsurface composition. In addition, polarimetric decomposition components, which capture different radar scattering modes—odd, even, volume, and helix—allow scientists to distinguish between terrain types and geological formations with greater accuracy.
These advanced products were developed indigenously by ISRO’s Space Applications Centre (SAC) in Ahmedabad, using algorithms specifically designed for the full-polarimetric L-band data. The datasets have been made freely available through ISRO’s Indian Space Science Data Centre (ISSDC) PRADAN portal. The availability of ready-to-use mosaics marks an important milestone, as researchers worldwide can now access high-quality radar data of the lunar poles for analysis, resource mapping, and potential landing site identification for future missions.
The Moon’s polar regions are of tremendous scientific and practical importance. These zones are believed to preserve early chemical and physical conditions of the solar system, locked away in cold, shadow-rich environments. Moreover, the identification of water-ice or hydrated minerals in these regions could play a critical role in supporting future lunar exploration, habitation plans, and in-situ resource utilisation. The CPR and T-Ratio metrics from the new data products provide enhanced capabilities to characterise potential volatile reservoirs, enabling a deeper understanding of the Moon’s hidden resources.
The high-resolution imagery and polarimetric data also contribute to refining global models of lunar mineralogy and surface evolution. When combined with hyperspectral and other remote-sensing datasets, scientists can build a comprehensive picture of the Moon’s geological and compositional diversity, particularly under the unique environmental conditions near its poles.
With the release of these advanced radar-derived data products from the Chandrayaan-2 mission, ISRO has significantly strengthened India’s contribution to lunar science and exploration. The availability of full-polarimetric L-band mosaics covering the Moon’s polar regions marks a critical step toward unlocking the Moon’s hidden ice, subsurface structures, and geological history. As global interest in the lunar poles intensifies, these datasets are expected to play a vital role in shaping future missions, guiding exploration targets, and deepening humanity’s understanding of Earth’s closest celestial neighbour.
