Context:
On World Environment Day (5 Jun), ISRO shared additional details about the TRISHNA mission.
Key highlights:
- TRISHNA (Thermal infraRed Imaging Satellite for High-resolution Natural Resource Assessment) is a joint project between the French Space Agency, the National Centre for Space Studies (CNES), and the Indian Space Research Organization (ISRO).
- The TRISHNA satellite will be similar to the NASA-ISRO Synthetic Aperture Radar Satellite (NISAR), which will also help monitor Earth’s deformations and climate change.
- It operates in a sun-synchronous orbit at an altitude of 761 km.
- TRISHNA will image the Earth every three days at a resolution of 57 meters for land and coastal areas and 1 km for oceanic and polar regions. It will cover a wide temperature range from about -20°C to +30°C with high precision.
Instruments:
TRISHNA features two sensors:
- Thermal InfraRed (TIR) Sensor: Measures surface temperature, radiance, and emissivity.
- Visible and Near Infrared (VNIR)/Short Wave InfraRed (SWIR) Sensor: Provides observations in six VNIR/SWIR bands, offering crucial information on water use, vegetation, land coverage, and more.
Mission Objectives:
Land Surface Temperature Monitoring: TRISHNA will carry a high-resolution thermal infrared camera to measure land surface temperature variations. This data will be crucial for:
- Urban Heat Island (UHI) Assessment: It will aid in understanding the “heat island effect” in urban areas, where temperatures are significantly higher than surrounding rural areas. This information can aid urban planners in developing heat mitigation strategies.
- Water Stress Monitoring: Identifying regions experiencing water scarcity by evapotranspiration monitoring and analyzing variations in land surface temperature and vegetation health.
NASA-ISRO Synthetic Aperture Radar (NISAR) mission
- It is a joint project between NASA and ISRO (Indian Space Research Organisation).
- NISAR is a Low Earth Orbit (LEO) and will carry a dual-frequency synthetic aperture radar, making it the first radar imaging satellite to operate at two different frequencies.
Mission Overview:
- NISAR’s primary purpose is to map Earth’s land and ice masses by collecting advanced radar imaging data.
- It will measure elevation changes with impressive precision—up to 5 to 10 meters—four to six times a month.
- The satellite aims to observe complex natural processes, including ecosystem disturbances, ice-sheet dynamics, and natural hazards like earthquakes and landslides
- Disaster Management: Supporting efforts in mitigating wildfires and other heat-related disasters through real-time temperature monitoring.
Coastal and Inland Water Quality Assessment: The mission will also gather data on water quality in coastal and inland water bodies. This can help in:
- Pollution Detection: Identifying sources of pollution affecting water quality.
- Monitoring Algal Blooms: Tracking the growth and movement of harmful algal blooms, which can have ecological and economic impacts.
Applications and Benefits:
- Agriculture: Improving crop yield estimation, irrigation management, and drought prediction.
- Environment: Monitoring climate change impacts, deforestation, and desertification.
- Urban Planning: Developing sustainable cities that are resilient to heat waves and other extreme climate events.
- Disaster Management: Strengthening preparedness and response measures for natural disasters.
Challenges and the Road Ahead:
- Meeting Technical Specifications: Building a high-resolution thermal camera with the desired accuracy and sensitivity is a significant engineering challenge.
- Integration with Existing Systems: Integrating TRISHNA’s data with information from other Earth observation systems will ensure a comprehensive picture of Earth’s biosphere.