Key Facts and Data Points

  • IRS‑1A launch year: 1988 (first Indian Remote Sensing satellite).\
  • Current constellation: Over 30 satellites covering optical, hyperspectral, SAR and cartographic missions (e.g., Resourcesat‑2, HysIS, Cartosat‑3, RISAT‑2A, NISAR).\
  • Major indices:
  • NDVI (Normalized Difference Vegetation Index) – assesses vegetation health using Red & Near‑Infrared bands.\
  • NDWI / MNDWI (Normalized Difference Water Index / Modified) – delineates water bodies using Green & NIR (or SWIR) bands.\
  • SAR (Synthetic Aperture Radar) – active microwave sensor; works day/night and through clouds.\
  • Geospatial platforms: Bhuvan, Yuktdhara geo‑portal, Geo‑MGNREGA, SIS‑DP, PMKSY‑WDC 2.0 dashboard.\
  • Policy framework: National Geospatial Policy, 2022; Disaster Management Support Programme (DMSP).\

Background and Context

  • Remote sensing is the science of observing Earth from space or air using sensors that detect reflected or emitted electromagnetic radiation. Different materials have unique spectral signatures, enabling identification of vegetation, water, minerals, soils, and built‑up areas without physical contact.\
  • Indian Remote Sensing Programme (IRS) was initiated by ISRO to provide satellite imagery for national development. It has evolved from low‑resolution IRS‑1 series to high‑resolution Cartosat, hyperspectral HysIS and all‑weather RISAT missions.\
  • Integration with governance: Satellite data feed into GIS‑based decision‑making tools for ministries, state governments and local bodies, forming the backbone of India’s geospatial ecosystem.

Significance for India / Governance / Policy

  • Agriculture: NDVI‑based crop health monitoring, precision irrigation, early warning of drought/flood, supporting PM‑Kisan and PM‑KSY.\
  • Water resources: SAR and optical indices map surface water, groundwater storage (via gravity‑measuring satellites), aiding river‑basin planning and groundwater depletion assessments.\
  • Forestry & Climate: Biomass and carbon stock estimation, forest fire detection, mangrove and coral monitoring, contributing to climate‑change mitigation commitments under the Paris Agreement.\
  • Mineral & Hydrocarbon Exploration: Hyperspectral sensors identify mineral spectral signatures; SAR and gravity data locate alteration zones and potential hydrocarbon traps.\
  • Disaster Management: Real‑time flood mapping, landslide susceptibility, cyclone damage assessment; feeds into NDMA early‑warning systems and insurance claim verification.\
  • Socio‑economic programmes: Geo‑tagging of MGNREGA assets (>6.24 crore), rural road mapping for PMGSY, urban housing monitoring under PMAY, and decentralized planning via SIS‑DP.

Related Constitutional / Legal Provisions

  • National Geospatial Policy, 2022: Mandates open access to high‑resolution geospatial data, encourages private‑sector participation, and aligns with the Digital India vision.\
  • Space Activities Bill (draft): Provides legal framework for satellite data sharing, privacy safeguards and national security considerations.\
  • Disaster Management Act, 2005: Recognises space‑based inputs as critical for hazard, vulnerability and risk (HVR) assessments.

Challenges

  • High cost and limited accessibility of very‑high‑resolution imagery.\
  • Cloud cover hampers optical sensors during monsoon.\
  • Capacity gaps at district‑level officials for GIS analysis.\
  • Data silos across ministries and states.\
  • Privacy and security concerns with detailed mapping of border areas.

Measures to Strengthen Remote Sensing

  • Open‑access data: Full implementation of the National Geospatial Policy to lower cost barriers.\
  • All‑weather monitoring: Expand SAR constellation (RISAT, NISAR) for flood and landslide mapping.\
  • Capacity building: Scale up ISRO‑IIRS training programmes for state and local officials.\
  • Integration with ground sensors: Link satellite data with IoT, drones and GIS dashboards under Smart Cities and PM‑Gati Shakti.\
  • Policy integration: Embed remote‑sensing indicators in sectoral schemes (e.g., PM‑KSY, PM‑AY) for evidence‑based fund release.

Drishti Mains Question: Examine the role of the Indian Remote Sensing (IRS) Programme in supporting sustainable development and governance.