Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Earth Observation Sensors: Spectral Indices & Exercise Introduction

Description

This lecture delves into selecting the appropriate data for Earth observation, covering topics such as spatial resolution, sensor types (satellite, drone, etc.), and data pricing. It explores the differences between active and passive sensors, emphasizing their applications and advantages. The lecture also discusses spectral indices, including multispectral and hyperspectral sensors, and their significance in extracting information about vegetation and other materials. Various spectral indices like NDVI, SAVI, and PVI are explained, along with their applications in studying vegetation health and other properties. The lecture concludes with an exercise introduction on computing vegetation indices and analyzing temporal NDVI values of different regions.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Official source

Related concepts (32)

Image sensor

An image sensor or imager is a sensor that detects and conveys information used to form an . It does so by converting the variable attenuation of light waves (as they pass through or reflect off objects) into signals, small bursts of current that convey the information. The waves can be light or other electromagnetic radiation. Image sensors are used in electronic imaging devices of both analog and digital types, which include digital cameras, camera modules, camera phones, optical mouse devices, medical imaging equipment, night vision equipment such as thermal imaging devices, radar, sonar, and others.

Sensor

A sensor is a device that produces an output signal for the purpose of sensing a physical phenomenon. In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends the information to other electronics, frequently a computer processor. Sensors are used in everyday objects such as touch-sensitive elevator buttons (tactile sensor) and lamps which dim or brighten by touching the base, and in innumerable applications of which most people are never aware.

Active-pixel sensor

An active-pixel sensor (APS) is an , which was invented by Peter J.W. Noble in 1968, where each pixel sensor unit cell has a photodetector (typically a pinned photodiode) and one or more active transistors. In a metal–oxide–semiconductor (MOS) active-pixel sensor, MOS field-effect transistors (MOSFETs) are used as amplifiers. There are different types of APS, including the early NMOS APS and the now much more common complementary MOS (CMOS) APS, also known as the CMOS sensor.

Information extraction

Information extraction (IE) is the task of automatically extracting structured information from unstructured and/or semi-structured machine-readable documents and other electronically represented sources. In most of the cases this activity concerns processing human language texts by means of natural language processing (NLP). Recent activities in multimedia document processing like automatic annotation and content extraction out of images/audio/video/documents could be seen as information extraction Due to the difficulty of the problem, current approaches to IE (as of 2010) focus on narrowly restricted domains.

Knowledge extraction

Knowledge extraction is the creation of knowledge from structured (relational databases, XML) and unstructured (text, documents, s) sources. The resulting knowledge needs to be in a machine-readable and machine-interpretable format and must represent knowledge in a manner that facilitates inferencing. Although it is methodically similar to information extraction (NLP) and ETL (data warehouse), the main criterion is that the extraction result goes beyond the creation of structured information or the transformation into a relational schema.

Related lectures (37)

Image Acquisition

Covers the basics of image acquisition, including optical devices, resolution factors, lens distortions, and sensor technologies.

Sensors: Understanding Microcontrollers

Explores different types of sensors and their interfaces with microcontrollers for various applications.

Earth Observation: Principles and Applications Log in to Mediaspace to watch this video

Covers the principles of Earth observation, focusing on satellite imagery and its applications in various fields.

CMOS Cameras: Advanced Pixel Design Techniques Log in to Mediaspace to watch this video

Covers advanced design techniques for CMOS cameras, focusing on pixel architecture and noise management in active pixel sensors.

Gas and Particle Sensors Log in to Mediaspace to watch this video