Passive Microwave Remote Sensing Quiz

The amount of microwave radiation emitted by a hypothetical blackbody at a specific wavelength.

A type of remote sensing that measures the naturally emitted microwave radiation from objects on Earth's surface.

Microwave radiation can penetrate clouds and some vegetation, allowing for measurements in various weather conditions and through some cover.

Microwave radiation can partially penetrate soil, providing information about soil moisture and depth.

Microwave radiation is emitted by objects regardless of the presence of sunlight, allowing for day and night monitoring.

The area of the surface that a sensor can detect at any one time. Passive microwave systems have a larger instantaneous field of view than visible or active microwave sensors, meaning they can cover a larger area at once but with lower spatial resolution.

The property of a material to absorb and emit electromagnetic radiation. In passive microwave sensing, changes in emissivity can make it difficult to interpret the data without ground truth information.

A technique used to measure the distance to an object by transmitting electromagnetic pulses and measuring the time it takes for the signal to return.

The portion of the transmitted signal that bounces back from a target and is received by the sensor. It is a key element in active remote sensing.

The wavelength of the emitted radiation affects the interaction with the target and the information captured. Longer wavelengths can penetrate through vegetation and see deeper into the ground.

The brightness temperature of the earth's surface is influenced by the soil moisture content. As soil gets wetter, the brightness temperature decreases.

The angle between the radar sensor and the ground. A smaller angle results in brighter imagery, while a larger angle leads to darker imagery.

This occurs when the radar signal from the top of a slope or feature reaches the sensor before the signal from its base, leading to a flipped or overlapped image.

This occurs when radar beams do not successfully illuminate the terrain, causing shadows to appear in the image and resulting in no recorded signals for those areas.

This occurs when slopes facing the radar sensor appear compressed due to the side-geometry of SAR. Distances on inclined surfaces are represented as shorter than they actually are.

RADAR images captured during ascending passes (satellite moving towards the north pole) look different from images captured during descending passes (satellite moving towards the south pole).

RADAR can be affected by surface properties like roughness and moisture content. The system's parameters, including wavelength, depression angle, and polarization, also play a role in data acquisition and interpretation.

RADAR is an all-weather satellite, which means it can gather data regardless of weather conditions. This makes it different from sun-synchronous satellites, which are limited by cloud cover.

The direction from which the RADAR sensor is looking at the Earth. It influences the resulting image due to different perspectives.

A phenomenon in RADAR imagery where slopes facing away from the sensor appear dark due to minimal signal return, contrasting with bright areas where the signal is reflected directly back. This happens when the radar signal is not hitting the surface at a perpendicular angle.

The measure of a material's ability to become polarized when exposed to an electric field, like a microwave. It dictates how much a signal will be reflected, absorbed, or transmitted by a material.

When a smooth surface reflects radar signals in one direction, creating a strong, focused reflection.

When a rough surface reflects radar signals in many directions, creating a weaker, scattered reflection.

A radar signal interaction where energy bounces between two surfaces, creating a stronger return signal.

A radar signal interaction where the signal penetrates a material and is scattered by internal structures, generating a signal return from within the material.

The way RADAR signals are impacted by the smoothness or roughness of a surface. Smooth surfaces create strong specular reflections, while rough surfaces result in weaker diffuse reflections.

The different ways RADAR signals interact with target materials, including surface scattering, double bounce scattering, and volume scattering. Each mechanism provides a unique signal characteristic.

A type of satellite remote sensing using radar technology to create images of the Earth's surface, even through cloud cover.

A satellite constellation designed to provide frequent and continuous SAR imaging data for various applications.

A type of remote sensing that uses a wide range of wavelengths across the electromagnetic spectrum to create detailed images. It captures hundreds of narrow, contiguous bands, usually from visible to infrared wavelengths.

A unique spectral signature that different materials on Earth emit when interacting with light. Every substance has a unique fingerprint, allowing us to identify it.

The highly detailed analysis of materials, even if they are small, using hyperspectral remote sensing data. This allows for precise identification and differentiation of materials by their spectral signatures.

A technology utilizing laser light to measure distances and create 3D models of the Earth's surface. It actively emits laser pulses and measures the time it takes for the light to return.

A technique that involves actively sending out a signal (like a laser pulse) and analyzing the reflected signal to gather information.

A technique that involves collecting and analyzing the natural energy emitted or reflected by the Earth's surface. This energy can be in the form of light, heat, or other electromagnetic radiation.

Millions of measurements obtained by LiDAR are used to create a 3D representation of a scanned area, showing the precise location of each point in space.

LiDAR can be used to create highly detailed digital elevation models, representing the terrain's topography with accurate heights.

A remote sensing technique that uses the reflections of GNSS satellite signals off the Earth's surface to gather information.

A type of radar that uses separate transmitters and receivers to analyze signals reflected off the Earth's surface, providing information on different surfaces and their characteristics.

Drones equipped with sensors provide flexibility in monitoring and are increasingly becoming an integral part of remote sensing applications.

A branch of artificial intelligence focused on using data and algorithms to mimic human learning processes, continuously enhancing its accuracy.

Machine learning techniques are used to analyze and interpret remote sensing data, enabling complex tasks such as object detection, classification, and change detection.