What is the Doppler notch?

A "Doppler notch" refers to a specific velocity range where a radar struggles to distinguish moving targets from stationary background clutter (like the ground) due to the Doppler effect, creating a "blind spot" or "notch" in its detection capability, often exploited in air combat maneuvers by flying perpendicular to the radar beam. In medicine, it can also describe an indentation in blood flow waveforms (Doppler ultrasound) indicating potential cardiovascular issues, like in the uterine or pulmonary arteries.

What is a Doppler notch?

Notching is the practice of exploiting Doppler radars' reliance on velocity measurement. It is sometimes called beaming because the maneuver is done by turning at a 90 degree angle to a tracking radar, and the left/right perpendicular directions to the aircraft are sometimes called the beam of the aircraft.

What is the diastolic notch on a Doppler?

Diastolic notch is defined as the slower velocity just after systolic flow but before maximum diastolic flow. To evaluate the depth of the notch, the diastolic notch index was used. The diastolic notch index was quantified by measuring the ratio between the early diastolic flow (A) and peak diastolic flow (B).

What does it mean to notch a radar?

8mo Edited. Radar Notching #Radar notching is a tactic used by fighter pilots to evade enemy radar, especially radar-guided missiles. It involves flying the aircraft in such a way that it hides from the enemy radar by exploiting its limitations.

What is a notch in dogfighting?

Notching means flying in a trajectory that is perpendicular in nature relative to the enemy locking radar. Take a look at your RWR while being locked, if you have one, and you will see a dashed line connecting opposition radar to your aircraft.

How Radars Tell Targets Apart (and When They Can’t) | Radar Resolution

What does a notch in a military dog tag mean?

The importance of the notch, again, was to hold the dog tag in place in the Addressograph which was a medical imprinter. Known as the “locating notch” in military manuals, the notch helped medical personnel properly seat the dog tag into the imprinter.

Has the F-35 ever been in a dog fight?

Yes, the F-35 has participated in simulated dogfights (Air Combat Maneuvering - ACM) and training exercises, often against older jets like the F-16 or Eurofighter, but its design prioritizes beyond-visual-range (BVR) stealth combat, meaning it's not built to excel in traditional, close-in "knife fights," and exercises sometimes put it at a disadvantage to highlight its strengths in modern warfare. While early tests showed limitations, later versions with updated software have shown better performance, with pilots even achieving impressive maneuvers in mock gun fights, proving it's capable when used as intended, or in specific scenarios. 

Has a tornado ever hit a Doppler radar?

NSSL has used an airborne Doppler radar (installed on NOAA's P-3 research aircraft) to study storms. The first direct measurements of a tornado recorded with an airborne Doppler radar were made by NSSL.

Why is it called a notch?

notch(n.) "a v-shaped nick or indentation," 1570s, probably a misdivision of an otch (see N for other examples), from French oche "notch," from Old French ochier "to notch," a word of unknown origin. Said to be unconnected to nock.

Does the USA have an anti-missile system?

Yes, the U.S. has a comprehensive, layered Ballistic Missile Defense System (BMDS) managed by the Missile Defense Agency (MDA), integrating ground, sea, and space-based assets like the Ground-Based Midcourse Defense (GMD) for ICBMs, Terminal High Altitude Area Defense (THAAD), Aegis BMD, and Patriot (PAC-3) for shorter-range threats, using sensors, radars, and interceptors to counter missiles across all flight phases.
 

How do you read a Doppler?

Red and blue on Doppler ultrasounds have specific meanings. Blood flowing toward the transducer (arterial blood flow) appears in red, whereas blood flowing away from the probe (venous blood flow) appears in blue.

What is a systolic notch?

Introduction. A systolic notch in the uterine artery (UtA) is an ominous sign in severe preeclampsia (PE) and is scarcely referenced in the literature (Thaler, 1992; Polat, 2015). Timing and hemodynamic conditions for its appearance remain unclear.

What is edv in Doppler?

Doppler sonography also enables determination of peak systolic velocity (PSV) and end-diastolic velocity (EDV), as well as the resistive index (RI) and pulsatility indices of the superior, inferior, intrathyroid, and intranodular arteries [5, 6].

What does a notch mean on an ultrasound?

Pathological Doppler indices on both uterine arteries meaning bilateral PI or RI > 90%-Interval or the presence of a notch between the 19th and 22th week of pregnancy represent a risk of developing severe adverse outcomes, such as preterm birth before 32 weeks of gestation, fetal growth restriction, severe pre- ...

How accurate is Doppler radar?

Weather radars are high-resolution velocity radars, while air defense radars have a large range of velocity detection, but the accuracy in velocity is in the tens of knots.

Why is notch important?

The Notch pathway plays an important role in the embryonic development as it controls cell proliferation, cell differentiation and binary cell fate decisions.

What is a notch in simple terms?

A notch is a small cut or nick in something. People make notches to keep track of things. If you've even seen a little U-shaped or V-shaped cut in something, you've seen a notch.

What is the significance of the cardiac notch?

The primary function of the cardiac notch is to provide space for the heart. The heart is a large organ that occupies a significant portion of the thoracic cavity. The cardiac notch allows the heart to fit comfortably within the thoracic cavity, ensuring that it does not compress the lungs or other nearby structures.

What state has never gotten a tornado?

Tornadoes have been documented in every U.S. state (not including the non-state territories of Guam, the Virgin Islands, American Samoa, and Puerto Rico) at least once since 1950, although some regions and states are hit by tornadoes far more than others.

What does God say about tornadoes?

The Bible describes "whirlwinds," like tornadoes, as powerful expressions of God's might, judgment, or a sign of divine upheaval, often linked to His presence (Nahum 1:3) or end-times prophecy (Matthew 24:8, Revelation), but it also warns against pinpointing specific disasters as God's direct punishment, emphasizing that creation groans under sin and that God offers refuge in Christ amidst chaos, promising ultimate restoration. 

Can a tornado pick up a Boeing 747?

Also, the wings would make the 747 more aerodynamic than the dead weight of a locomotive. So theoretically it would be possible for a 747 to be picked up by a strong tornado.

What plane has never lost a dogfight?

The Eagle took its maiden flight in July 1972, and entered service in 1976. It is among the most successful modern fighters, with 104 victories and no losses in aerial combat, with the majority of the kills by the Israeli Air Force.

How many 2000 lb bombs can a F-35 carry?

Carries just 5,700 pounds of internal weapons to minimize its radar cross-section. Once air superiority secured, can deploy external hardpoints, boosting its payload. Can carry up to 14 AMRAAMs and six 2,000-pound JDAM bombs. Only negative is Beast Mode cuts operational range in half.

Who would win in a dogfight, F-22 or F-35?

In a pure, one-on-one dogfight (Within Visual Range), the F-22 Raptor would likely win due to its superior speed, extreme maneuverability (thrust vectoring), and greater agility, as it's built for air superiority; however, the F-35 Lightning II excels in Beyond Visual Range (BVR) combat and networked operations, using its advanced sensors (EOTS/DAS) and data fusion to see the F-22 first, potentially taking it out before a dogfight even starts, making it a better force multiplier.