Radar signal processing

Sensitivity time control

Sensitivity time control (STC), also known as swept-gain control, is a system used to attenuate the very strong signals returned from nearby ground clutter targets in the first few range gates of a radar receiver. Without this attenuation, the receiver would routinely saturate due to the strong signals. This is used in air traffic control systems and has an influence on the shape of the elevation pattern of the surveillance antenna. It is represented in terms of numerical value typically expressed in decibels (dB), starting from zero, indicating that there is no muting and that the radar system is accepting all returns. The radar equation is based on the fourth root of range, meaning that doubling the range to a target results in sixteen times less energy being returned. STC is due to the corollary of this statement - nearby targets return orders of magnitude more radio signal. In the case of a long-range radar with high power outputs, the return from nearby targets can be so powerful that it causes the amplifiers to saturate, producing a blank area on the screen beyond which nothing can be detected until the amplifiers return to normal operation again. For early radar systems, the solution was to point the signal away from the ground. This can be difficult for ground or ship-based radars, which required other solutions. In the case of the ground-based AMES Type 7, for instance, the radars were installed in natural dish-like depressions so that all returns below a certain angle were cut off very close to the radar. This still had the same effect in terms of causing the amplifiers to saturate, but occurred so rapidly after transmission that the saturation decayed at relatively short ranges. The downside to this approach is that it permanently hides any signal below a certain angle, which for a very long-range system might prevent it from seeing anything near the radar site. STC addresses this problem by implementing a reverse gain curve with the same characteristics as the radar equation, that is, a fourth-root dependency or some function close to that (often there are discrete steps). This dramatically damps down amplification of signals received shortly after the detection pulse is sent, preventing them from saturating the receiver. The gain modification is reduced over time, until it reaches zero at some selected distance from the radar site, often on the order of 50 miles (80 km). Because the system works by muting nearby signals, it may have the side-effect of eliminating small targets near the radar. This is fine for many applications, like air traffic control, where the targets are large and nearby aircraft are often guided using a local-area radar. (Wikipedia).

Video thumbnail

Sensitivity (Electrical Engineering)

https://www.patreon.com/edmundsj If you want to see more of these videos, or would like to say thanks for this one, the best way you can do that is by becoming a patron - see the link above :). And a huge thank you to all my existing patrons - you make these videos possible. In this video

From playlist Advanced Circuit Design

Video thumbnail

Sensitivity Analysis

Overview of various methods for sensitivity analysis in the UQ of subsurface systems

From playlist Uncertainty Quantification

Video thumbnail

04-3 Sensitivity Analysis Trees

Sensitivity analysis using classification and regression trees

From playlist QUSS GS 260

Video thumbnail

04 1 Local Sensitivity Analysis

Local sensitivity analysis

From playlist QUSS GS 260

Video thumbnail

Chapter 12 Sensitivity Specificity Predictive Values Odds Ratios

Ever wandered how to calculate sensitivity, specificity, positive and negative predictive values or odds ratios or even simply what these terms mean? Watch this short lecture.

From playlist Medical Statistics

Video thumbnail

ISO Sensitivity

Digital cameras can adjust the sensitivity of the sensor, and this is known as the ISO number. For example, ISO 100 is a lower sensitivity, so it requires more light to create a good exposure. We hope you enjoy! To learn more, check out our written lesson here: https://edu.gcfglobal.org/e

From playlist Digital Photography

Video thumbnail

04-2 Sensitivity Analysis Global

Sobol' and regionalized sensitivity analysis

From playlist QUSS GS 260

Video thumbnail

Prob & Stats - Bayes Theorem (2 of 24) What is the Sensitivity of a Test?

Visit http://ilectureonline.com for more math and science lectures! In this video I will explain what is and give examples of the sensitivity of a test. The sensitivity of a test indicates the probability that the subject will have a POSITIVE result when the subject is actually POSITIVE.

From playlist PROB & STATS 4 BAYES THEOREM

Video thumbnail

The Step Response | Control Systems in Practice

Check out the other videos in this series: https://www.youtube.com/playlist?list=PLn8PRpmsu08pFBqgd_6Bi7msgkWFKL33b This video covers a few interesting things about the step response. We’ll look at what a step response is and some of the ways it can be used to specify design requirements f

From playlist Control Systems in Practice

Video thumbnail

Marcello Delitala: Combination therapies and drug resistance in heterogeneous tumoral populations

Abstract: How combination therapies can reduce the emergence of cancer resistance? Can we exploit intra-tumoral competition to modify the effectiveness of anti-cancer treatments? Bearing these questions in mind, we present a mathematical model of cancer-immune competition under therapies.

From playlist Mathematics in Science & Technology

Video thumbnail

Jenne Driggers - Improving the sensitivity of gravitational wave interferometers - IPAM at UCLA

Recorded 01 December 2021. Jenne Driggers of the California Institute of Technology presents "Improving the sensitivity of gravitational wave interferometers" at IPAM's Workshop IV: Big Data in Multi-Messenger Astrophysics. Abstract: The LIGO interferometers collect enormous amounts of dat

From playlist Workshop: Big Data in Multi-Messenger Astrophysics

Video thumbnail

Control Bootcamp: Sensitivity and Complementary Sensitivity (Part 2)

Here we explore the sensitivity and complementary sensitivity functions, which are critical in understanding robustness and performance. (Part 2) Code available at: faculty.washington.edu/sbrunton/control_bootcamp_code.zip These lectures follow Chapters 1 & 3 from: Machine learning con

From playlist Control Bootcamp

Video thumbnail

Control Bootcamp: Limitations on Robustness

This video describes some of the fundamental limitations of robustness, including time delays and right-half plane zeros. Code available at: faculty.washington.edu/sbrunton/control_bootcamp_code.zip These lectures follow Chapters 1 & 3 from: Machine learning control, by Duriez, Brunto

From playlist Control Bootcamp

Video thumbnail

Excel Magic Trick 1391: Case Sensitive VLOOKUP? 5 Examples of Excel Case Sensitive Lookup

Download Files: Start File and Finished File: https://excelisfun.net/files/EMT1391.xlsm Download File: https://excelisfun.net/files/excelisfun.htm See how to create a formula to perform Case Sensitive Lookup: 1. (00:10) Introduction 2. (00:16) VLOOKUP by itself will NOT work. 3. (01:1

From playlist Excel Lookup Functions & Formulas Beg - Adv

Video thumbnail

Gabriele Vajente - Machine Learning and Gravitational Wave Detectors - IPAM at UCLA

Recorded 02 December 2021. Gabriele Vajente of the California Institute of Technology presents "Machine Learning and Gravitational Wave Detectors" at IPAM's Workshop IV: Big Data in Multi-Messenger Astrophysics. Abstract: The use of machine learning techniques in the analysis of the data p

From playlist Workshop: Big Data in Multi-Messenger Astrophysics

Video thumbnail

Forward Sensitivity Approach to dynamic data assimilation - S. Lakshmivarahan

PROGRAM: Data Assimilation Research Program Venue: Centre for Applicable Mathematics-TIFR and Indian Institute of Science Dates: 04 - 23 July, 2011 DESCRIPTION: Data assimilation (DA) is a powerful and versatile method for combining observational data of a system with its dynamical mod

From playlist Data Assimilation Research Program

Video thumbnail

Magnetic resonance at the quantum limit and beyond by Patrice Bertet

Open Quantum Systems DATE: 17 July 2017 to 04 August 2017 VENUE: Ramanujan Lecture Hall, ICTS Bangalore There have been major recent breakthroughs, both experimental and theoretical, in the field of Open Quantum Systems. The aim of this program is to bring together leaders in the Open Q

From playlist Open Quantum Systems

Video thumbnail

The Gang of Six in Control Theory | Control Systems in Practice

Check out the other videos in the series: Part 1 - What Does a Control Engineer Do? https://youtu.be/ApMz1-MK9IQ Part 2 - What Is Gain Scheduling? https://youtu.be/YiUjAV1bhKs Part 3 - What Is Feedforward Control? https://youtu.be/FW_ay7K4jPE Part 4 - Why Time Delay Matters https://youtu.b

From playlist Control Systems in Practice

Video thumbnail

30. Climate Sensitivity and Human Population

The Atmosphere, the Ocean and Environmental Change (GG 140) Climate sensitivity is defined as either the temperature change resulting from a doubling of atmospheric carbon dioxide concentration or the temperature change resulting from a 1W/m2 increase in radiative forcing. There are se

From playlist Atmosphere, Ocean and Environmental Change with Ron Smith

Video thumbnail

Jo van den Brand: Gravitational Waves, The Present and the Future - 3/3 🌌⎪CERN

Gravitational waves detection and measurements, the discovery of which was announced to the world in 2016, is a fast moving field. Several events have been detected in LIGO and LIGO+VIRGO, and in spectacular coincidence with gamma ray burst detectors. Clearly we are just at the start of th

From playlist CERN Academic Lectures

Related pages

Decibel | Range gate