TRISHNA satellite is in advanced stage of realisation, says ISRO official

TRISHNA stands for Thermal Infra-Red Imaging Satellite for High-resolution Natural Resource Assessment. It is an Indo-French Earth-observation mission developed by ISRO and France’s CNES. The satellite will monitor Earth’s surface at high spatial and temporal resolution. This matters because detailed, repeated observations can support better understanding and management of natural resources, especially water.

Its measurements will include surface temperature, emissivity, and biophysical and radiation variables. TRISHNA will use visible, near-infrared, shortwave-infrared, and thermal-infrared observations. Together, these measurements can show how land surfaces are behaving and how energy and water conditions vary across regions.

The mission is now moving toward launch after about a decade of conceptualisation and formalisation. ISRO and CNES are jointly developing it, and the data will be processed in India and France. An open data policy will make science data available worldwide.

TRISHNA is expected to launch in the next 12–16 months, according to Jasvinder Singh Khoral, Director (Projects) at the U.R. Rao Satellite Centre. That places the mission in the final stretch of development after years of planning. The project has been under conceptualisation and formalisation for about a decade.

The launch vehicle will be the Polar Satellite Launch Vehicle, or PSLV. The satellite is being prepared through cooperation between ISRO and France’s CNES. This partnership follows two earlier India-France satellite projects: Megha-Tropiques and SARAL.

The mission is not yet in orbit. It is at the realisation stage, with launch expected within the stated 12–16-month window. URSC will realise the satellite bus and contribute its payload, while CNES delivers the other payload. The agencies will also process the mission’s data jointly.

The article does not give a percentage split for the satellite’s development. Instead, it describes the partners’ responsibilities. India’s U.R. Rao Satellite Centre will realise the satellite bus and the payloads assigned to ISRO. France’s CNES will deliver the other half of the payloads.

TRISHNA will carry two primary payloads. The Thermal Infra-Red, or TIR, payload is being developed by CNES. The Visible-Near Infra-Red Short Wave Infra-Red, or VNIR-SWIR, payload is being developed by ISRO. These instruments provide complementary views of Earth’s surface.

The division reflects a joint mission rather than a simple ownership split. ISRO supplies the spacecraft platform and one main instrument, while CNES supplies the other main instrument. The agencies will also process the data together in India and France, supporting shared scientific use.

TRISHNA’s main objective is better management of water resources. It will monitor Earth’s surface temperature, emissivity, and related biophysical and radiation variables at high spatial and temporal resolution. This matters because water conditions can vary sharply from one place to another and change over time.

For example, repeated observations could reveal different surface-temperature patterns across agricultural or natural-resource regions. Thermal measurements would provide temperature information, while visible and shortwave-infrared observations would add environmental detail. Together, these data support surface-energy budgeting, which is central to understanding conditions at the land surface.

The mission is designed to work at regional to global scales. It will not manage water directly, but it will provide measurements for analysis and planning. The article identifies water management as the main objective and says science data will be openly disseminated worldwide.

Earth’s surface contains information in different parts of the electromagnetic spectrum. Thermal-infrared observations are suited to measuring emitted heat, helping estimate surface temperature and emissivity. Visible and shortwave-infrared observations capture reflected light, which provides different clues about surface materials and biophysical conditions.

TRISHNA combines these views through two primary payloads. CNES is developing the Thermal Infra-Red payload, while ISRO is developing the Visible-Near Infra-Red Short Wave Infra-Red payload. For example, thermal data can show temperature patterns, while visible and shortwave-infrared data add information about surface and biological characteristics.

The combination supports monitoring of surface energy and related variables at regional to global scales. The article specifically links the mission to surface-energy budgeting and water-resource management. Using both instrument types therefore helps researchers interpret Earth’s surface more completely than relying on one spectral range alone.

TRISHNA’s data system is designed around cooperation between the two partner countries. Jasvinder Singh Khoral said the data would be processed jointly in France and India. This shared approach matches the mission’s joint development by ISRO and CNES.

The data will come from the satellite’s two primary payloads: CNES’s Thermal Infra-Red instrument and ISRO’s VNIR-SWIR instrument. Processing these observations turns measurements of surface temperature, emissivity, and other variables into science data that researchers can study. The mission is intended to support analysis from regional to global scales.

The project also plans an open data policy. Nagalakshmi A.M. said science data would be disseminated to the entire globe seamlessly. This means the mission is intended to serve a worldwide research community rather than remain limited to the agencies that built it. The article does not specify the exact distribution platform or release schedule.

Remote sensing is the measurement of Earth from a distance, rather than by placing an instrument directly on the ground. A satellite sensor records energy that surfaces reflect or emit. This lets researchers observe broad areas repeatedly and compare how conditions change across space and time.

TRISHNA’s thermal-infrared payload will detect emitted heat, which can be used to estimate surface temperature and emissivity. Its visible, near-infrared, and shortwave-infrared payload will measure reflected sunlight in selected wavelength ranges. Scientists use these signals with calibration and analysis methods to estimate biophysical and radiation variables, including patterns related to vegetation and surface energy.

The article says TRISHNA will deliver high spatial and temporal resolution measurements for surface-energy budgeting at regional to global scales. It also identifies water-resource management as the mission’s main objective. The satellite therefore observes without touching the ground, while data processing converts signals into useful environmental information.