Water in system of Soil, Vegetation and Atmosphere

The interaction of water within the system of soil, vegetation, and the atmosphere is a fundamental component of Earth's hydrological cycle. This cycle describes how water continuously moves and circulates through these interconnected components:

1. Soil: Soil acts as a reservoir for water. When it rains or snows, water infiltrates the soil, a process known as infiltration. Some of this water is immediately taken up by plant roots, while the rest moves deeper into the soil, becoming groundwater. Soil also stores moisture that plants can access later through their root systems.

2. Vegetation: Plants play a crucial role in this system. Through a process called transpiration, they absorb water from the soil through their roots and release it into the atmosphere as water vapor through tiny openings in their leaves called stomata. This release of water vapor is similar to the way we humans perspire to cool down. This process not only sustains plant growth but also contributes to the moisture content of the atmosphere.

3. Atmosphere: The atmosphere contains water vapor, which is the gaseous form of water. This water vapor is crucial for weather patterns and precipitation. When enough water vapor accumulates in the atmosphere and conditions are right, it can condense to form clouds. Eventually, these clouds release water droplets as precipitation, which falls back to the Earth's surface as rain, snow, sleet, or hail. This is known as the process of condensation and precipitation.

This continuous movement of water between the soil, vegetation, and the atmosphere is essential for maintaining the Earth's ecosystems, supporting plant growth, regulating temperatures, and providing freshwater resources for human use. It's a dynamic cycle where water constantly changes state from liquid (in soil and surface water) to vapor (in the atmosphere) and back again through processes like evaporation, transpiration, condensation, and precipitation. This delicate balance is vital for the sustainability of life on Earth.

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Optical Sensors in Remote Sensing

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Radar Sensors in Remote Sensing

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Thermal Sensors in Remote Sensing

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Geometric Correction

When satellite or aerial images are captured, they often contain distortions (errors in shape, scale, or position) caused by many factors — like Earth's curvature, satellite motion, terrain height (relief), or the Earth's rotation . These distortions make the image not properly aligned with real-world coordinates (latitude and longitude). 👉 Geometric correction is the process of removing these distortions so that every pixel in the image correctly represents its location on the Earth's surface. After geometric correction, the image becomes geographically referenced and can be used with maps and GIS data. Types 1. Systematic Correction Systematic errors are predictable and can be modeled mathematically. They occur due to the geometry and movement of the satellite sensor or the Earth. Common systematic distortions: Scan skew – due to the motion of the sensor as it scans the Earth. Mirror velocity variation – scanning mirror moves at a va...

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LiDAR (Light Detection and Ranging) is an active remote sensing technology that uses laser pulses to measure distances to the Earth's surface and create high-resolution 3D maps . LiDAR sensors emit short pulses of laser light (usually in the near-infrared range) and measure the time it takes for the pulse to return after hitting an object. Because LiDAR measures distance very precisely, it is excellent for mapping: terrain vegetation height buildings forests coastlines flood plains ✅ 1. Active Sensor LiDAR sends its own laser energy, unlike passive sensors that rely on sunlight. ✅ 2. Laser Pulse LiDAR emits thousands of pulses per second (even millions). Wavelengths commonly used: Near-Infrared (NIR) → land and vegetation mapping Green (532 nm) → water/ bathymetry (penetrates shallow water) ✅ 3. Time of Flight (TOF) The sensor measures the time taken for the laser to travel: from the sensor → to the sur...

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