Millimeter-wave cloud radars, also denominated cloud radars, are radar systems designed to monitor clouds with operating frequencies between 24 and 110 GHz. Accordingly, their wavelengths range from 1 mm to 1.11 cm, about ten times shorter than those used in conventional S band radars such as NEXRAD.
Synthetic-aperture radar (SAR) is a form of radar that is used to create two-dimensional images or three-dimensional reconstructions of objects, such as landscapes. SAR uses the motion of the radar antenna over a target region to provide finer spatial resolution than conventional stationary beam-scanning radars. SAR is typically mounted on a moving platform, such as an aircraft or spacecraft, and has its origins in an advanced form of side looking airborne radar (SLAR). The distance the SAR device travels over a target during the period when the target scene is illuminated creates the large synthetic antenna aperture. Typically, the larger the aperture, the higher the image resolution will be, regardless of whether the aperture is physical or synthetic – this allows SAR to create high-resolution images with comparatively small physical antennas. For a fixed antenna size and orientation, objects which are further away remain illuminated longer – therefore SAR has the property of creating larger synthetic apertures for more distant objects, which results in a consistent spatial resolution over a range of viewing distances.
In physics and geosciences, the term spatial resolution refers to distance between independent measurements, or the physical dimension that represents a pixel of the image. While in some instruments, like cameras and telescopes, spatial resolution is directly connected to angular resolution, other instruments, like synthetic aperture radar or a network of weather stations, produce data whose spatial sampling layout is more related to the Earth's surface, such as in remote sensing and satellite imagery.
Radioglaciology is the study of glaciers, ice sheets, ice caps and icy moons using ice penetrating radar. It employs a geophysical method similar to ground-penetrating radar and typically operates at frequencies in the MF, HF, VHF and UHF portions of the radio spectrum. This technique is also commonly referred to as "Ice Penetrating Radar (IPR)" or "Radio Echo Sounding (RES)".
GNSS reflectometry involves making measurements from the reflections from the Earth of navigation signals from Global Navigation Satellite Systems such as GPS. The idea of using reflected GNSS signal for earth observation became more and more popular in the mid-1990s at NASA Langley Research Center and is also known as GPS reflectometry. Research applications of GNSS-R are found in
Atmospheric correction is the process of removing the scattering and absorption effects of the atmosphere on the reflectance values of images taken by satellite or airborne sensors. Atmospheric effects in optical remote sensing are significant and complex, dramatically altering the spectral nature of the radiation reaching the remote sensor. The atmosphere both absorbs and scatters various wavelengths of the visible spectrum which must pass through the atmosphere twice, once from the sun to the object and then again as it travels back up the image sensor. These distortions are corrected using various approaches and techniques, as described below.
Speckle, speckle pattern, or speckle noise is a granular noise texture degrading the quality as a consequence of interference among wavefronts in coherent imaging systems, such as radar, synthetic aperture radar (SAR), medical ultrasound and optical coherence tomography. Speckle is not external noise; rather, it is an inherent fluctuation in diffuse reflections, because the scatterers are not identical for each cell, and the coherent illumination wave is highly sensitive to small variations in phase changes.
Allen R. Miller (1942–2010) was an American mathematician.
The Cyclone Global Navigation Satellite System (CYGNSS) is a space-based system developed by the University of Michigan and Southwest Research Institute with the aim of improving hurricane forecasting by better understanding the interactions between the sea and the air near the core of a storm.
Behara Seshadri Daya Sagar also known as B. S. Daya Sagar is an Indian mathematical geoscientist specializing in mathematical morphology. He is a professor of computer science at the Indian Statistical Institute, Bangalore. He is known as a specialist in mathematical morphology, fractal geometry. chaos theory, and their applications in geophysics, geographical information science, and computational geography. The Indian Geophysical Union awarded him the Krishnan Medal in 2002. He is the first Asian to receive the Georges Matheron Lectureship in 2011. In 2018, he received the IAMG Certificate of Appreciation by the International Association for Mathematical Geosciences for his work on the Handbook of Mathematical Geosciences. In 2020, Sagar was selected as an IEEE Distinguished Lecturer (DL) to represent the IEEE Geoscience and Remote Sensing Society. He, with Frits Agterberg, Qiuming Cheng, and Jennifer McKinley, led the monumental project on the Encyclopedia of Mathematical Geosciences to the completion. The first edition of two-volume 1756-page Encyclopedia of Mathematical Geosciences was published on 21st June 2023 by Springer International Publishers.
The Canada Centre for Mapping and Earth Observation (CCMEO) (formerly Canada Centre for Remote Sensing (CCRS)) is a branch of Natural Resources Canada's Earth Science Sector. It was created in 1970 with Lawrence Morley as the first Director General. The department also works closely with the private sector, especially with the development of GIS software.
Gaofen is a series of Chinese high-resolution Earth imaging satellites launched as part of the China High-resolution Earth Observation System (CHEOS) program. CHEOS is a state-sponsored, civilian Earth-observation program used for agricultural, disaster, resource, and environmental monitoring. Proposed in 2006 and approved in 2010, the CHEOS program consists of the Gaofen series of space-based satellites, near-space and airborne systems such as airships and UAVs, ground systems that conduct data receipt, processing, calibration, and taskings, and a system of applications that fuse observation data with other sources to produce usable information and knowledge.
JoBea Way Holt is an American planetary scientist who has worked for NASA. Holt studied the carbon cycle in Earth's atmosphere. She is also a member of the Climate Project, and is the author of several books and research papers.
Frank Silvio Marzano was a professor at the Sapienza University of Rome, Italy who was named Fellow of the Institute of Electrical and Electronics Engineers (IEEE) in 2016 for contributions to microwave remote sensing in meteorology and volcanology. He was also a Fellow of the UK Royal Meteorological Society since 2012. In 2020 Dr. Marzano was inserted in the World's Top 2% Scientists database of Stanford University (USA).
Dr. Y. S. Rao is a professor at the Centre of Studies in Resources Engineering, Indian Institute of Technology Bombay, Mumbai, India. He is working in the field of microwave remote sensing and land based applications for more than 34 years. His early research was focused on the use of Synthetic Aperture Radar (SAR) interferometry for landslides and land deformation monitoring, Digital Elevation Model generation, snow and glacier monitoring. He is also actively involved in developing several techniques for soil moisture estimation using passive and active microwave remote sensing data for more than 25 years. His current research involves SAR Polarimetry for crop characterization, classification, biophysical parameter retrieval using linear and compact-pol SAR data. Apart from applications, he has also contributed in the field of Polarimetric SAR system calibration and software tool development.
Fauzia Ahmad is an associate professor of electrical engineering at Temple University. Her research considers statistical signal processing and ultrasonic guided wave structural health monitoring. She serves as associate editor of the IEEE Transactions on Aerospace and Electronic Systems and Geoscience and Remote Sensing Society. She is a Fellow of the Institute of Electrical and Electronics Engineers and SPIE.
The railSAR, also known as the ultra-wideband Foliage Penetration Synthetic Aperture Radar, is a rail-guided, low-frequency impulse radar system that can detect and discern target objects hidden behind foliage. It was designed and developed by the U.S. Army Research Laboratory (ARL) in the early 1990s in order to demonstrate the capabilities of an airborne SAR for foliage and ground penetration. However, since conducting accurate, repeatable measurements on an airborne platform was both challenging and expensive, the railSAR was built on the rooftop of a four-story building within the Army Research Laboratory compound along a 104-meter laser-leveled track.
The boomSAR is a mobile ultra-wideband synthetic aperture radar system designed by the U.S. Army Research Laboratory (ARL) in the mid-1990s to detect buried landmines and IEDs. Mounted atop a 45-meter telescoping boom on a stable moving vehicle, the boomSAR transmits low frequency short-pulse UWB signals over the side of the vehicle to scope out a 300-meter range area starting 50 meters from the base of the boom. It travels at an approximate rate of 1 km/hour and requires a relatively flat road that is wide enough to accommodate its 18 ft-wide base.
Mahta Moghaddam is an Iranian-American electrical and computer engineer and William M. Hogue Professor of Electrical Engineering in the Ming Hsieh Department of Electrical and Computer Engineering at the University of Southern California Viterbi School of Engineering. Moghaddam is also the president of the IEEE Antennas and Propagation Society and is known for developing sensor systems and algorithms for high-resolution characterization of the environment to quantify the effects of climate change. She also has developed innovative tools using microwave technology to visualize biological structures and target them in real-time with high-power focused microwave ablation.
Atmospheric correction for Interferometric Synthetic ApertureRadar (InSAR) technique is a set of different methods to remove artefact displacement from an interferogram caused by the effect of weather variables such as humidity, temperature, and pressure. An interferogram is generated by processing two synthetic-aperture radar images before and after a geophysical event like an earthquake. Corrections for atmospheric variations are an important stage of InSAR data processing in many study areas to measure surface displacement because relative humidity differences of 20% can cause inaccuracies of 10–14 cm InSAR due to varying delays in the radar signal. Overall, atmospheric correction methods can be divided into two categories: a) Using Atmospheric Phase Screen (APS) statistical properties and b) Using auxiliary (external) data such as GPS measurements, multi-spectral observations, local meteorological models, and global atmospheric models.
