Satellites Remote Sensing

Earth Resources Satellites

These satellites are designed mainly for natural resource monitoring – land, water, vegetation, and environment.

1. LANDSAT (USA, since 1972)

World's first dedicated Earth observation satellite series.
Provides long-term continuous data for >50 years.
Sensors: MSS (Multispectral Scanner), TM (Thematic Mapper), ETM+ (Enhanced TM), OLI (Operational Land Imager).
Resolution: 15–30 m (optical).
Applications: Land cover change, agriculture, forests, water resources.
Fact: Landsat archive is the longest continuous Earth observation record.

2. SPOT (France, 1986 onwards)

Name: Satellite Pour l'Observation de la Terre.
Sensors: HRV (High Resolution Visible), HRVIR (with Infrared).
Resolution: 1.5–20 m.
Applications: Urban studies, vegetation monitoring, mapping.
Fact: First civilian satellite to offer stereo imaging (3D views).

3. IRS (India, 1988 onwards)

Name: Indian Remote Sensing Satellite Series.
Sensors: LISS (Linear Imaging Self Scanner), PAN (Panchromatic), WiFS (Wide Field Sensor).
Resolution: 5–180 m depending on sensor.
Applications: Agriculture, water resources, forestry, disaster management.
Fact: India's IRS program is one of the largest civilian remote sensing programs in the world.

4. IKONOS (USA, launched 1999)

One of the first commercial high-resolution satellites.
Resolution: 1 m (panchromatic), 4 m (multispectral).
Applications: Urban planning, infrastructure mapping, defense, precision agriculture.
Fact: Made high-resolution satellite imagery available for civilian use.

Meteorological Satellites

These satellites are designed for weather and climate monitoring.

1. INSAT (India)

Name: Indian National Satellite System.
Operates in Geostationary Orbit (GEO, ~36,000 km).
Functions: Weather forecasting, cyclone tracking, rainfall estimation, communication.
Fact: INSAT combines meteorology + telecommunications + broadcasting.

2. NOAA (USA)

Name: National Oceanic and Atmospheric Administration Satellites.
Operates in Polar Orbit (LEO ~850 km).
Sensor: AVHRR (Advanced Very High Resolution Radiometer).
Applications: Sea surface temperature, vegetation, snow cover, weather monitoring.
Fact: Continuous data since 1970s, key for climate change studies.

3. GOES (USA)

Name: Geostationary Operational Environmental Satellites.
Orbit: Geostationary (36,000 km).
Applications: Real-time weather monitoring, storm tracking, atmosphere studies.
Fact: Provides continuous images of the same region every few minutes → crucial for cyclone and hurricane monitoring.

Optical Mechanical Scanners

These are instruments (sensors) that scan the Earth's surface in different wavelengths of the electromagnetic spectrum.

1. MSS (Multispectral Scanner) – Landsat

Records data in 4 spectral bands (visible + near IR).
Spatial resolution: ~80 m.
Use: Early land cover studies.

2. TM (Thematic Mapper) – Landsat

Improved sensor with 7 bands (visible, NIR, SWIR, thermal).
Spatial resolution: 30 m (optical), 120 m (thermal).
Use: Agriculture, geology, vegetation, water.

3. LISS (Linear Imaging Self Scanner) – IRS

Variants: LISS-I, II, III, IV.
Resolutions: 72 m (LISS-I) → 5.8 m (LISS-IV).
Use: Agriculture, forestry, resources.

4. WiFS (Wide Field Sensor) – IRS

Wide coverage, ~180 m resolution.
Use: Vegetation and crop monitoring at regional scale.

5. PAN (Panchromatic) – IRS

Records in single broad band (black & white).
Very high spatial resolution: ~5–6 m.
Use: Urban mapping, cartography, image fusion.

In short:

Earth Resource Satellites (LANDSAT, SPOT, IRS, IKONOS) → monitor land, vegetation, water.
Meteorological Satellites (INSAT, NOAA, GOES) → monitor atmosphere, weather, climate.
Optical Scanners (MSS, TM, LISS, WiFS, PAN) → instruments onboard satellites that capture data in different resolutions and spectral ranges.

🛰️

Comments

Types of Remote Sensing

Remote Sensing means collecting information about the Earth's surface without touching it , usually using satellites, aircraft, or drones . There are different types of remote sensing based on the energy source and the wavelength region used. 🛰️ 1. Active Remote Sensing 📘 Concept: In active remote sensing , the sensor sends out its own energy (like a signal or pulse) to the Earth's surface. The sensor then records the reflected or backscattered energy that comes back from the surface. ⚙️ Key Terminology: Transmitter: sends energy (like a radar pulse or laser beam). Receiver: detects the energy that bounces back. Backscatter: energy that is reflected back to the sensor. 📊 Examples of Active Sensors: RADAR (Radio Detection and Ranging): Uses microwave signals to detect surface roughness, soil moisture, or ocean waves. LiDAR (Light Detection and Ranging): Uses laser light (near-infrared) to measure elevation, vegetation...

Energy Interaction with Atmosphere and Earth Surface

In Remote Sensing , satellites record electromagnetic radiation (EMR) that is reflected or emitted from the Earth. Before reaching the sensor, radiation interacts with: The Atmosphere The Earth's Surface These interactions control how satellite images look and how we interpret them. I. Interaction of EMR with the Atmosphere When solar radiation travels from the Sun to the Earth, four main processes occur: 1. Absorption Definition: Absorption occurs when atmospheric gases absorb radiation at specific wavelengths and convert it into heat. Main absorbing gases: Ozone (O₃) → absorbs Ultraviolet (UV) Carbon dioxide (CO₂) → absorbs Thermal Infrared Water vapour (H₂O) → absorbs Infrared Concept: Atmospheric Windows These are wavelength regions where absorption is very low, allowing radiation to pass through the atmosphere. Remote sensing depends on these windows. For example, satellites like Landsat 8 use visible, near-infrared, and thermal bands located in atmospheric windows. 2. Trans...

Platforms in Remote Sensing

In remote sensing, a platform is the physical structure or vehicle that carries a sensor (camera, scanner, radar, etc.) to observe and collect information about the Earth's surface. Platforms are classified mainly by their altitude and mobility : Ground-Based Platforms Definition : Sensors mounted on the Earth's surface or very close to it. Examples : Tripods, towers, ground vehicles, handheld instruments. Applications : Calibration and validation of satellite data Detailed local studies (e.g., soil properties, vegetation health, air quality) Strength : High spatial detail but limited coverage. Airborne Platforms Definition : Sensors carried by aircraft, balloons, or drones (UAVs). Altitude : A few hundred meters to ~20 km. Examples : Airplanes with multispectral scanners UAVs with high-resolution cameras or LiDAR High-altitude balloons (stratospheric platforms) Applications : Local-to-regional mapping ...

Government of Kerala Initiatives for Water Management

Kerala, with its abundant rainfall and network of rivers, faces a dual challenge of water scarcity and excess —seasonal droughts and monsoon floods. The state government has implemented various policies and programs to address these challenges through sustainable water conservation, management, and distribution practices . Below is a detailed breakdown of the major water management initiatives in Kerala. 1. Jal Jeevan Mission (JJM) – Kerala Implementation Objective: To provide functional household tap connections (FHTC) to all rural households by 2024. Focuses on source sustainability and community-led water resource management. Key Features: Water Quality Monitoring & Surveillance: Ensures supply of safe drinking water through real-time monitoring. Decentralized Approach: Implementation through gram panchayats and local self-governments (LSGs) . Recharge & Conservation Measures: Rainwater harvesting, groundwater recharge, and watershed development inte...

Vineesh V, Geography

Search This Blog