Komponen Penginderaan Jauh I

Summary

The lecture focuses on remote sensing and photogrammetry, discussing key components of remote sensing systems. It covers energy sources, the electromagnetic spectrum, and the impact of the atmosphere on data acquisition. The role of active and passive sensors, influenced by energy sources like the sun or artificial means, is explained. The lecture also delves into the behavior of electromagnetic waves interacting with objects on Earth, including reflection and scattering. Additionally, it highlights atmospheric effects on wave transmission and the concept of atmospheric windows critical for remote sensing applications.

Takeaways

• 🌞 Remote sensing involves several components such as energy sources, atmosphere, interaction between energy and objects, sensors, data acquisition, and data usage.
• ⚡ The main energy source in passive remote sensing is the sun, while active sensing uses artificial energy sources, such as radar systems using microwaves.
• 📡 Electromagnetic waves interact with the atmosphere, where some waves are absorbed, scattered, or transmitted before reaching Earth.
• 🌐 Electromagnetic waves include various wavelengths like visible light, infrared, and microwaves. Shorter wavelengths carry more energy than longer ones.
• ☁️ Atmospheric conditions, such as clouds, can block or scatter electromagnetic waves, affecting data acquisition in remote sensing.
• 🛰️ Reflected electromagnetic waves from Earth's surface are captured by satellite sensors for data analysis.
• 📊 The amount of energy an object receives depends on factors like sun angle, time of day, weather, and Earth's surface topography.
• 🌍 The atmosphere influences the transmission of electromagnetic waves, creating atmospheric windows where certain wavelengths pass through to Earth's surface.
• 📷 Different types of remote sensing systems (photographic, thermal, multispectral, radar) operate in specific wavelength ranges within the electromagnetic spectrum.
• 💨 Scattering types include Rayleigh (affects blue light, making the sky appear blue), Mie (occurs with aerosols and pollution), and non-selective (occurs with larger particles like water droplets, causing white clouds).

Q & A

What are the main components of remote sensing?

The main components of remote sensing are the energy source, atmosphere, interaction between energy and objects, sensors (satellites), data acquisition, and data usage.

How does the Sun serve as a source of energy in passive remote sensing?

In passive remote sensing, the Sun emits electromagnetic waves that interact with the Earth's surface and atmosphere. The reflected energy from the surface is then captured by sensors on satellites.

What is the difference between active and passive remote sensing?

Active remote sensing uses artificial energy sources, such as radar, to emit electromagnetic waves, while passive remote sensing relies on natural energy sources like the Sun.

How does the Earth's topography affect the energy received from the Sun?

Topography influences the amount of energy an object receives from the Sun. For example, areas facing the Sun on a hill may receive more energy than those in shadow.

What role does the atmosphere play in remote sensing?

The atmosphere affects how electromagnetic waves propagate. It can absorb, scatter, or reflect these waves, influencing the quality and amount of data received by sensors.

What is Rayleigh scattering, and how does it affect the color of the sky?

Rayleigh scattering occurs when electromagnetic waves interact with particles smaller than the wavelength, like gas molecules in the atmosphere. It causes the blue light to scatter more than other colors, making the sky appear blue during the day.

Why does the sky appear red or orange during sunset?

During sunset, the blue light has already been scattered away due to the longer path through the atmosphere, leaving primarily red and yellow wavelengths to reach the observer.

What is the atmospheric window in remote sensing?

The atmospheric window refers to parts of the electromagnetic spectrum that can pass through the atmosphere without significant absorption or scattering, allowing these waves to reach the Earth's surface and be used in remote sensing.

How do weather conditions, like clouds, affect remote sensing data?

Clouds can block or scatter electromagnetic waves, limiting the ability of sensors to capture accurate data from the Earth's surface beneath the clouds.

What types of electromagnetic waves are used in remote sensing?

Different parts of the electromagnetic spectrum are used in remote sensing, including visible light, infrared, microwave, and radio waves, depending on the type of data being captured.