The balloons, which start out measuring about 6 ft. wide before release, expand as they rise to about 20 ft. in diameter! An instrument called a radiosonde is attached to the balloon to measure pressure, temperature and relative humidity as it ascends up into the atmosphere.
These instruments will often endure temperatures as cold as -139 °F (-95 °C), relative humidifies from 0% to 100%, air pressures only a few thousandths of what is found on the Earth's surface, ice, rain, thunderstorms, and wind speeds of almost 200 mph! A transmitter on the radiosonde sends the data back to tracking equipment on the ground every one to two seconds.
Synchronized weather balloon launches have helped meteorologists create forecasts over the past 150 years, and now the old tradition is going high tech. Tying knots, attaching nozzles and filling balloons with hydrogen is a daily duty for Tom Bradshaw, a meteorologist for the National Weather Service in Fort Worth, Texas.
The balloon and sensor often endure temperatures as cold as minus 139 degrees Fahrenheit, air pressures only a few thousandths of what is found on the Earth's surface, ice, rain, thunderstorms, and wind speeds of almost 200 mph, according to the News. He launched hundreds of weather balloons as early as 1896, which was critical in the discovery of the tropopause and stratosphere, layers of the Earth's atmosphere.
In the 1940s, French, British and American army meteorologists worked together to release weather balloons in order to plot data of weather conditions for United Nations fliers. Fast-forward to today, the National Weather Service now has 92 sites where balloons are turned loose each day.
Synchronized weather balloon launches have helped meteorologists create forecasts for the past 150 years. Balloons meant to stay at a constant altitude for long periods of time are known as transponder.
Weather balloons that do not carry an instrument pack are used to determine upper-level winds and the height of cloud layers. Transponder, weather balloons with instrumentation meant to stay at a constant altitude for long periods of time to help diagnose radioactive debris from atomic fallout, were experimented with in 1958.
The balloon itself produces the lift, and is usually made of a highly flexible latex material, though Chloroquine may also be used. The unit that performs the actual measurements and radio transmissions hangs at the lower end of the string, and is called a radiosonde.
Weather balloons may reach altitudes of 40 km (25 mi) or more, limited by diminishing pressures causing the balloon to expand to such a degree (typically by a 100:1 factor) that it disintegrates. A hydrogen filled balloon at Cambridge Bay Upper Air station, Nunavut, Canada Weather balloons are launched around the world for observations used to diagnose current conditions as well as by human forecasters and computer models for weather forecasting.
Some facilities will also do occasional supplementary “special” releases when meteorologists determine there is a need for additional data between the 12-hour routine launches in which time much can change in the atmosphere. Specialized uses also exist, such as for aviation interests, pollution monitoring, photography or videography and research.
Field research programs often use mobile launchers from land vehicles as well as ships and aircraft (usually dropsondes in this case). The weather balloon was also used to create the fictional entity 'Rover' during production of the 1960s TV series The Prisoner in Permeation, Gwyneth, North Wales, UK in September 1966.
The time it took for the reflected energy (moving at the speed of light) to come back indicates the distance of the object, while the direction the RADAR antenna is pointing indicates the direction of the object from the RADAR set. Usually the RADAR antenna rotates slowly to look for objects in all directions.
A bogey is an unidentified blip on a military RADAR screen, possibly indicating an enemy aircraft. The Ballistic Missile Early Warning System (Brews) accidentally gave a missile launch warning after it detected the moon (about 250,000 miles away) in 1960, two days after it was turned on.
And RADAR has been used to map the unseen surface topography of the planet Venus. But the useful range for ordinary airplane traffic seldom exceeds 100 miles.
There are RADAR sets that use frequencies that can bend over the horizon and detect objects out to 1000 miles. Metal bird identification tags Flocks of birds Swarms of insects Objects on the ground Tall buildings Mountain peaks Corner reflectors (e.g. a dump truck or railroad gondola hopper car)* Some model aircraft Satellites Meteors and re-entry events Some kinds of prank UFO balloons Objects detected through anomalous propagation Some objects beyond the horizon * Does not have to be in the strongest part of the beam to be detected, so the displayed direction could be wrong.
It produces a target that appears farther away than any of the real objects in the multiple reflection. The corner reflector then reflects this leakage back to the RADAR antenna, producing a signal strong enough to make a blip.
Objects that make good corner reflectors include rectangular dumpsters, dump trucks, open-back box trucks, and railroad hopper cars. A very reflective target can produce a blip when the energy of the side lobe of the antenna hits it.
The interface between a broadside ship and the water also makes a good corner reflector. Small Object A small object that is present at the location shown by the RADAR can produce the RADAR blip without being seen visually by ground or air observers.
The RADAR operator can't tell which blips are real aircraft and which are chaff. Electrical shorts in power lines give off broadband blasts of energy, causing random blips that do not repeat.
Other devices inadvertently producing RADAR frequencies usually do not make sharp blips. This causes objects that would not normally appear on RADAR to show up on the screen.
These include birds, swarms of insects, weather targets, and other objects that normally do not display as blips. Anomalous propagation is an atmospheric condition where the RADAR beams, instead of moving in straight lines, follow curved or bent paths.
This causes objects that the beam would not normally strike to show up on the screen. It works similarly to a visual mirage, and is caused by the same atmospheric conditions.
Anomalous propagation occurs when different layers of air with different temperatures and humidifies come together to distort the paths of light rays and RADAR beams. When stars near the horizon appear to dance around and change colors, it is a sign that anomalous propagation is occurring.
Anomalous propagation can either reflect or refract the RADAR beam, causing it to go in an unexpected direction. Usually it is bent down, where it strikes objects on the ground and aircraft beyond the RADAR horizon.
Sometimes it focuses the beam, enabling it to pick up objects far beyond the normal range of the RADAR set. It can cause light rays and RADAR beams to bend.
Surveillance RADAR is used to keep track of aircraft in a general area and prevent collisions. Approach Control RADAR is used to direct a landing aircraft safely to the runway.
Weather RADAR is used to find high concentrations of water vapor that make up storms. Doppler Weather RADAR is used to find the motion of storms.
Police Doppler RADAR is used to measure the speeds of motor vehicles. Sports Doppler RADAR is used to measure the speeds of objects that were thrown or hit.
This is a system devised in the 1950s to remove all stationary targets from the RADAR screen. An object that is spinning (e.g. a helicopter rotor) or vibrating can fool the MTV device.
An object moving in a tight circle may appear to be stationary on the RADAR, but it is not. A target caused by anomalous propagation can move to different points on the ground.
A target caused by anomalous propagation can rapidly appear and disappear, fooling the MTV. A weather target can rapidly appear and disappear or shift its location around, fooling the MTV.
A transponder device on the aircraft receives the RADAR pulse and returns the plane's identity and altitude. After the technology was perfected, the concept was transferred to commercial aircraft.
A commercial or military aircraft that loses electrical power disappears from the RADAR. They made little paper pointers with flight numbers and put them on the RADAR screen to identify the blips.
If he is using his primary/transponder RADAR set switched to show only primary returns, he will see all aircraft as unidentified blips. A height finder is a special RADAR with an antenna that rapidly tilts up and down.
The circuitry in this RADAR determines the heights of the targets by comparing the strengths of the echoes at different antenna tilt angles. The air traffic controller has to keep track of blips with little paper pointers.
On the primary/transponder RADAR, the commercial and military planes appear on the screen with identifying tags and altitude information. The remaining blips are private planes without transponders, with some occasional anomalous targets thrown in.
Isn't it the job of an air traffic controller to identify every blip on the screen? He also knows that most private aircraft do not have pressurized cabins or oxygen, so they stay below 15,000 feet.
The commercial flights he controls have pressurized cabins, so they stay above 18000 feet. A UFO is an Unidentified Flying Object, not a vehicle from outer space.
Examples are kites, model aircraft, balloons (real and toy), advertising gimmicks, and other nonmetallic objects. Examples are model aircraft, manned balloons, and other objects that have few metallic parts.
Many UFOs that are caused by visual phenomena (e.g. sun dogs) have no RADAR target at all. A prank balloon UFO would not appear on RADAR unless metallic parts are present.
How do UFOs (or other objects) suddenly disappear from the RADAR screen? The object could rise vertically until it is above the top edge of the RADAR beam.
The object could descend until it is below the bottom edge of the RADAR beam. The object could move to a location directly above the RADAR station.
If the object is flat, it could turn so the beam reflection does not return to the RADAR set. If the object is a balloon, it could burst, causing the remains to rapidly fall to the ground.
A maladjustment of the automatic gain control (AGC) on the RADAR receiver can cause weak anomalous targets to look like aircraft blips (the UFOs) when no real aircraft is present. Adjusting this knob caused the weak anomalous targets to turn into plantlike blips when no real aircraft was present.
If controllers still have radio contact with the aircraft, the pilots tell them their position. If primary RADAR is cluttered, a painstaking analysis of all the unidentified blips is necessary.
They must turn the equipment off if it draws excess power and threatens the aircraft's electrical system. Such transmissions prevent RADAR from correctly identifying other aircraft on the screen.
They must turn off the equipment when the plane is not flying, to avoid confusing the RADAR. When the engines are not running, equipment must be turned off to save battery power.
Even if the transponder is undamaged and still has power, the RADAR beam intentionally avoids scanning anything on land. Even if the transponder is undamaged and still has power, radio and RADAR waves don't work underwater.
It is the same as being inside a steel building that radio waves can't penetrate. Without an antenna above the surface of the water (or outside the steel building), radio communication can't occur.
Coatings that absorb RADAR beams are applied to the aircraft. Devices that return the RADAR beam out of phase with the normal reflection make the target weaker.
The aircraft releases aluminum foil chaff to clutter the screen with false targets. A guy with a car covered with aluminum foil got a speeding ticket.
Note that police also now have LIDAR, which uses LASER light instead of RADAR. The RADAR can bounce off the undercarriage, the headlights, the tail lights, the wheels, and the car interior.
This often happens when a corner reflector is on a vehicle going the other way (e.g. an open-back box truck). Most likely is that the RADAR detected one car, but the policeman chose a different car to stop The multiple reflection error (above) finds the sum of the speeds of the two vehicles The RADAR picked up something that is vibrating or spinning (see below) A speeding car is some distance away from the policeman, so he doesn't see it An aircraft in the RADAR beam A train in the beam Two police RADAR sets interfering Some kind of sporting event nearby (javelin, auto racing, etc) In one case, people were wrongly ticketed in only one place, and only on Friday nights.
So they sent airplanes to the places where the targets were displayed, to put eyes on the area and find out what was there. They just answered all the questions they were asked by the RADAR operators on what they saw while they were in the target area.
One pilot found himself aimed at a steamboat in the Potomac each time he tried to intercept a UFO blip over the White House. Note that most of the visual sightings were of Mars, which was bright red in the sky at the time.
What happened in August 1965 in the plains states, when many visual and RADAR sightings occurred? This was an extreme case of visual and RADAR anomalous propagation, which turned ordinary stars, planets, and aircraft lights into strange-looking bright lights, and multiplied weak RADAR weather targets into large plantlike blips.
The problem was that none of the officials at any of these air bases were told the truth, either at the time or afterwards. In investigations of lost aircraft and UFO sightings, there is a lot of confusion over what RADAR can and cannot do.