Jicamarca Radio Observatory - AbsoluteAstronomy.com

The Jicamarca Radio Observatory (JRO) is the equatorial

Equatorial

Equatorial may refer to:* Equator of the Earth* Equatorial climate in meteorology* The ring-shaped outer boundary of the cross-section of a round three dimensional shape or object in geometry* The equatorial bond of a molecule in chemistry...

anchor of the Western Hemisphere

Western Hemisphere

The Western Hemisphere or western hemisphere is mainly used as a geographical term for the half of the Earth that lies west of the Prime Meridian and east of the Antimeridian , the other half being called the Eastern Hemisphere.In this sense, the western hemisphere consists of the western portions...

chain of Incoherent Scatter

Incoherent scatter

Incoherent scattering is a type of scattering phenomenon in physics, which may involve various particles, such as neutrons or photons.One application is a ground-based technique for studying the Earth's ionosphere. A radar beam scattering off electrons in the ionospheric plasma creates an...

Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

(ISR) observatories extending from Lima

Lima

Lima is the capital and the largest city of Peru. It is located in the valleys of the Chillón, Rímac and Lurín rivers, in the central part of the country, on a desert coast overlooking the Pacific Ocean. Together with the seaport of Callao, it forms a contiguous urban area known as the Lima...

, Peru

Peru

Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

to Søndre Strømfjord, Greenland

Greenland

Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...

. JRO is the premier scientific facility in the world for studying the equatorial ionosphere

Ionosphere

The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...

. The Observatory

Observatory

An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed...

is about half an hour drive inland (east) from Lima and 10 km from the Central Highway (11°57′05"S 76°52′27.5"W, 520 meters ASL). The magnetic dip angle

Magnetic dip

Magnetic dip or magnetic inclination is the angle made by a compass needle with the horizontal at any point on the Earth's surface. Positive values of inclination indicate that the field is pointing downward, into the Earth, at the point of measurement...

is about 1°, and varies slightly with altitude and year. The radar can accurately determine the direction of the Earth's magnetic field (B) and can be pointed perpendicular to B at altitudes throughout the ionosphere

Ionosphere

. The study of the equatorial ionosphere

Ionosphere

is rapidly becoming a mature field due in large part due to the contributions made by JRO in radio

Radio

Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...

science

Science

Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...

.

JRO’s main antenna

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

is the largest of all the incoherent scatter

Incoherent scatter

radars in the world. The main antenna consists of a 300m x 300m square array composed of 18,432 cross-polarized dipole

Dipole

In physics, there are several kinds of dipoles:*An electric dipole is a separation of positive and negative charges. The simplest example of this is a pair of electric charges of equal magnitude but opposite sign, separated by some distance. A permanent electric dipole is called an electret.*A...

s. The main research

Research

Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...

areas of the observatories are: the stable equatorial ionosphere, ionospheric field aligned irregularities

Field aligned irregularities

Field Aligned Irregularities are anisotropic perturbations of plasma density associated with magnetic fields. FAI are usually thought of in the context of the Earth's ionosphere, where several natural processes generate FAI in the E region and F region....

, the dynamics of the equatorial neutral atmosphere

Atmosphere

An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...

and meteor

Meteoroid

A meteoroid is a sand- to boulder-sized particle of debris in the Solar System. The visible path of a meteoroid that enters Earth's atmosphere is called a meteor, or colloquially a shooting star or falling star. If a meteoroid reaches the ground and survives impact, then it is called a meteorite...

physics

Physics

Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

.

The Observatory is a facility of the Instituto Geofisico del Peru operated with support from the US National Science Foundation

National Science Foundation

The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...

Cooperative Agreements through Cornell University

Cornell University

Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...

History

The Jicamarca Radio Observatory was built in 1960-61 by the Central Radio Propagation Laboratory (CRPL) of the National Bureau of Standards (NBS). This lab later became part of the Environmental Science Service Administration (ESSA) and then the National Oceanic and Atmospheric Administration (NOAA). The project was led by Dr. Kenneth L. Bowles

Kenneth Bowles

Dr. Kenneth L "Ken" Bowles is best known for his work in initiating and directing the UCSD Pascal project, when he was a professor of Computer Science at the University of California, San Diego .- Education :Bowles received his PhD under Prof...

, who is known as the “father of JRO”.

Although the last dipole

Dipole

was installed on April 27, 1962, the first incoherent scatter

Incoherent scatter

measurements at Jicamarca were made in early August 1961, using part of the total area projected and without the transmitter

Transmitter

In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating...

's final stage. In 1969 ESSA turned the Observatory over to the Instituto Geofísico del Perú (IGP), which had been cooperating with CRPL during the International Geophysical Year

International Geophysical Year

The International Geophysical Year was an international scientific project that lasted from July 1, 1957, to December 31, 1958. It marked the end of a long period during the Cold War when scientific interchange between East and West was seriously interrupted...

(IGY) in 1957-58 and had been intimately involved with all aspects of the construction and operation of Jicamarca. ESSA and then NOAA continued to provide some support to the operations for several years after 1969, in major part due to the efforts of the informal group called “Jicamarca Amigos” led by Prof. William E. Gordon

William E. Gordon

William Edward Gordon was a physicist and astronomer. He is referred to as the "father of the Arecibo Observatory"....

. Prof. Gordon invented the incoherent scatter

Incoherent scatter

radar

Radar

technique in 1958.

A few years later the National Science Foundation

National Science Foundation

began partially supporting the operation of Jicamarca, first through NOAA, and since 1979 through Cornell University

Cornell University

via Cooperative Agreements. In 1991, a nonprofit Peruvian organization—called Ciencia Internacional (CI) -- was created to hire most observatory staff members and to provide services and goods to the IGP to run the Observatory.

Since 1969, the great majority of the radar

Radar

components have been replaced and modernized with “home made” hardware and software, designed and built by Peruvian engineer

Engineer

An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

s and technician

Technician

A technician is a worker in a field of technology who is proficient in the relevant skills and techniques, with a relatively practical understanding of the theoretical principles. Experienced technicians in a specific tool domain typically have intermediate understanding of theory and expert...

s. More than 60 Ph.D. students

Ph.D.

A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...

, many from US institutions and 15 from Peru, have done their research in association with Jicamarca.

Main Radar

JRO’s main instrument is the VHF radar

Radar

that operates at 50 MHz

Hertz

The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....

and is used to study the physics

Physics

of the equatorial ionosphere

Ionosphere

and neutral atmosphere

Atmosphere

. Like any other radar

Radar

, its main components are: antenna

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

, transmitter

Transmitter

s, receivers, radar controller, acquisition and processing system. The main distinctive characteristics of JRO’s radar are: (1) the antenna

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

(the largest of all the ISRs in the world) and (2) the powerful transmitters.

Radar Components

Antenna
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

. The main antenna consists of 18432 cross-polarized half-wavelength dipole
Dipole
In physics, there are several kinds of dipoles:*An electric dipole is a separation of positive and negative charges. The simplest example of this is a pair of electric charges of equal magnitude but opposite sign, separated by some distance. A permanent electric dipole is called an electret.*A...

s occupying an area of 288m x 288m. The array is subdivided in quarters, each quarter consisting of 4x4 modules. The main beam of the array can be manually steer +/- 3 degrees from its on-axis position, by changing cables at the module level. Being modular, the array can be configured in both transmission and reception on a variety of configurations, allowing for example: simultaneous multi-beam observations, applications of multi-baseline radar interferometry as well as radar imaging, etc.
Transmitter
Transmitter
In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating...

s. Currently, JRO has three transmitters, capable of delivering 1.5 MW
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

peak power each. Soon a fourth transmitter will be finished to allow the transmission of 6 MW as in the early days. Each transmitter can be fed independently and can be connected to any quarter section of the main array. This flexibility allows the possibility of transmitting any polarization: linear, circular or elliptical.
Other. The remaining components of the radar are constantly being changed and modernized according to the technology
Technology
Technology is the making, usage, and knowledge of tools, machines, techniques, crafts, systems or methods of organization in order to solve a problem or perform a specific function. It can also refer to the collection of such tools, machinery, and procedures. The word technology comes ;...

available. Modern electronic devices are used for assembling the receivers, radar controller and acquisition system. The first computer in Peru came to JRO in the early 1960s. Since then, different computer generations
History of computing hardware
The history of computing hardware is the record of the ongoing effort to make computer hardware faster, cheaper, and capable of storing more data....

and systems have been used.

Radar Modes of Operation

The main radar operates in mainly two modes: (1) incoherent scatter

Incoherent scatter

radar

Radar

(ISR) mode, and (2) coherent scatter

Scattering

Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more localized non-uniformities in the medium through which they pass. In conventional use, this also includes deviation of...

(CSR) mode. In the ISR mode using the high power transmitter, Jicamarca measures the electron density

Electron density

Electron density is the measure of the probability of an electron being present at a specific location.In molecules, regions of electron density are usually found around the atom, and its bonds...

, electron

Electron

The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...

and ion

Ion

An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...

temperature

Temperature

Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...

, ion composition and vertical and zonal electric fields in the equatorial ionosphere

Ionosphere

. Given its location and frequency of operation, Jicamarca has the unique capability of measuring the absolute electron density

Electron density

Electron density is the measure of the probability of an electron being present at a specific location.In molecules, regions of electron density are usually found around the atom, and its bonds...

via Faraday rotation, and the most precise ionospheric electric fields by pointing the beam perpendicular

Perpendicular

In geometry, two lines or planes are considered perpendicular to each other if they form congruent adjacent angles . The term may be used as a noun or adjective...

to the Earth’s magnetic field. In the CSR mode the radar

Radar

measures the echoes that are more than 30 dB

Decibel

The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...

stronger than the ISR echoes. These echoes come from equatorial irregularities generated in troposphere

Troposphere

The troposphere is the lowest portion of Earth's atmosphere. It contains approximately 80% of the atmosphere's mass and 99% of its water vapor and aerosols....

, stratosphere

Stratosphere

The stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler...

, mesosphere

Mesosphere

The mesosphere is the layer of the Earth's atmosphere that is directly above the stratosphere and directly below the thermosphere. In the mesosphere temperature decreases with increasing height. The upper boundary of the mesosphere is the mesopause, which can be the coldest naturally occurring...

, equatorial electrojet

Equatorial electrojet

The equatorial electrojet is a narrow ribbon of current flowing eastward in the day time equatorial region of the Earth's ionosphere. The abnormally large amplitude of variations in the horizontal components measured at equatorial geomagnetic observatories, as a result of EEJ, was noticed as early...

, E and F region

F region

The F region of the ionosphere is home to the F layer of ionization, also called the Appleton layer, after the English physicist Edward Appleton. As with other ionospheric sectors, 'layer' implies a concentration of plasma, while 'region' is the area that contains the said layer...

. Given the strength of the echoes, usually low power

Power (physics)

In physics, power is the rate at which energy is transferred, used, or transformed. For example, the rate at which a light bulb transforms electrical energy into heat and light is measured in watts—the more wattage, the more power, or equivalently the more electrical energy is used per unit...

transmitters and/or smaller antenna sections are used.

JULIA Radar

JULIA stands for Jicamarca Unattended Long-term Investigations of the Ionosphere

Ionosphere

and Atmosphere

Atmosphere

, a descriptive name for a system designed to observe equatorial plasma

Plasma (physics)

In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...

irregularities and neutral atmospheric wave

Wave

In physics, a wave is a disturbance that travels through space and time, accompanied by the transfer of energy.Waves travel and the wave motion transfers energy from one point to another, often with no permanent displacement of the particles of the medium—that is, with little or no associated mass...

s for extended periods of time. JULIA is an independent PC

Personal computer

A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

-based data acquisition system that makes use of some of the exciter stages of the Jicamarca main radar

Radar

along with the main antenna

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

array. In many ways, this system duplicates the function of the Jicamarca radar

Radar

except that it does not use the main high-power transmitters, which are expensive and labor intensive to operate and maintain. It can therefore run unsupervised for long intervals. With its pair of 30 kW

Watt

The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

peak power pulsed transmitters driving a (300 m)^2 modular antenna array, JULIA is a formidable coherent scatter

Scattering

radar

Radar

. It is uniquely suited for studying the day-to-day and long-term variability of equatorial irregularities, which until now have only been investigated episodically or in campaign mode.

A large quantity of ionospheric irregularity data have been collected during CEDAR MISETA campaigns beginning in August, 1996, and continuing through the present. Data include daytime observations of the equatorial electrojet, 150 km echoes and nighttime observations of equatorial spread F.

Other Instruments

Besides the main radar and JULIA, JRO hosts, and/or helps in the operations of, a variety of radar

Radar

s as well as radio

Radio

and optical

Optics

Optics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...

instruments

Scientific instrument

A scientific instrument can be any type of equipment, machine, apparatus or device as is specifically designed, constructed and often, through trial and error, ingeniously refined to apply utmost efficiency in the utilization of well proven physical principle, relationship or technology to...

to complement their main observation

Observation

Observation is either an activity of a living being, such as a human, consisting of receiving knowledge of the outside world through the senses, or the recording of data using scientific instruments. The term may also refer to any data collected during this activity...

s. These instruments are: various ground-based magnetometers distributed through Peru

Peru

, a digital ionosonde

Ionosonde

An ionosonde, or chirpsounder, is a special radar for the examination of the ionosphere. An ionosonde consists of:* A high frequency transmitter, automatically tunable over a wide range...

, many GPS receivers in South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

, an all-sky specular meteor

METEOR

METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...

radar

Radar

, a bistatic Jicamarca-Paracas

Paracas Peninsula

The Paracas Peninsula is a desert peninsula within the boundaries of the Paracas National Reservation, a marine reserve which extends south along the coast. The only marine reserve in Peru, it is a designated UNESCO World Heritage Site....

CSR for measuring E region electron density

Electron density

Electron density is the measure of the probability of an electron being present at a specific location.In molecules, regions of electron density are usually found around the atom, and its bonds...

profile, scintillation

Scintillation (astronomy)

Scintillation or twinkling are generic terms for rapid variations in apparent brightness or color of a distant luminous object viewed through a medium, most commonly the atmosphere ....

receivers in Ancon

Ancón District

Ancón is a district of northern Lima Province in Peru. It is a popular beach resort, visited every summer by hundreds of people from Lima.Officially established as a district on October 29, 1874, the current mayor of Ancón is Jaime Jesús Pajuelo Torres. The district's postal code is...

, a Fabry–Perot Interferometer in Arequipa

Arequipa

Arequipa is the capital city of the Arequipa Region in southern Peru. With a population of 836,859 it is the second most populous city of the country...

, a small prototype of AMISR UHF radar

Radar

, …

Main Research Areas

The main research areas of JRO are the studies of: the equatorial stable ionosphere, the equatorial field aligned irregularities

Field aligned irregularities

, equatorial neutral atmosphere

Atmosphere

dynamics, and meteor

METEOR

METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...

physics

Physics

.
Here are some examples of the JRO topics

Stable ionosphere
- Topside
  Magnetosphere
  A magnetosphere is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the intrinsic magnetic field of a planet or similar body. Earth is surrounded by a magnetosphere, as are the other planets with intrinsic magnetic fields: Mercury, Jupiter,...
  
  : What controls the light ion
  Ion
  An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
  
  distribution? Why are the equatorial profiles so different from those at Arecibo
  Arecibo Observatory
  The Arecibo Observatory is a radio telescope near the city of Arecibo in Puerto Rico. It is operated by SRI International under cooperative agreement with the National Science Foundation...
  
  ? What is the storm
  Geomagnetic storm
  A geomagnetic storm is a temporary disturbance of the Earth's magnetosphere caused by a disturbance in the interplanetary medium. A geomagnetic storm is a major component of space weather and provides the input for many other components of space weather...
  
  time response of the topside?
- F region
  F region
  The F region of the ionosphere is home to the F layer of ionization, also called the Appleton layer, after the English physicist Edward Appleton. As with other ionospheric sectors, 'layer' implies a concentration of plasma, while 'region' is the area that contains the said layer...
  
  : Do current theories fully explain electron
  Electron
  The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
  
  and ion
  Ion
  An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
  
  thermal balance? Do we understand the electron collision
  Collision theory
  Collision theory is a theory proposed by Max Trautz and William Lewis in 1916 and 1918, that qualitatively explains how chemical reactions occur and why reaction rates differ for different reactions. For a reaction to occur the reactant particles must collide. Only a certain fraction of the total...
  
  effects on ISR
  Incoherent scatter
  Incoherent scattering is a type of scattering phenomenon in physics, which may involve various particles, such as neutrons or photons.One application is a ground-based technique for studying the Earth's ionosphere. A radar beam scattering off electrons in the ionospheric plasma creates an...
  
  theory now? What is the effect of F-region
  F region
  The F region of the ionosphere is home to the F layer of ionization, also called the Appleton layer, after the English physicist Edward Appleton. As with other ionospheric sectors, 'layer' implies a concentration of plasma, while 'region' is the area that contains the said layer...
  
  dynamics near sunset on the generation of ESF plumes? What are the effects of N-S wind
  Wind
  Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...
  
  s on inter-hemispheric transport?
- E region: What are the basic background parameters in the equatorial E region? What is the morphology of the density profiles in this difficult to probe region? How does this morphology affect the E-region dynamo?
- D region
  D region
  The D region is the portion of the ionosphere that exists approximately 50 to 95 km above the surface of the Earth.Note: Attenuation of radio waves, caused by ionospheric free-electron density generated by solar radiation, is pronounced during daylight hours. Because solar radiation is not...
  
  : What effects do meteor
  METEOR
  METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...
  
  ablation
  Ablation
  Ablation is removal of material from the surface of an object by vaporization, chipping, or other erosive processes. This occurs in spaceflight during ascent and atmospheric reentry, glaciology, medicine, and passive fire protection.-Spaceflight:...
  
  and mesospheric mixing have on the composition in this region?
Unstable Ionosphere
- F region
  F region
  The F region of the ionosphere is home to the F layer of ionization, also called the Appleton layer, after the English physicist Edward Appleton. As with other ionospheric sectors, 'layer' implies a concentration of plasma, while 'region' is the area that contains the said layer...
  
  :
  What are the fundamental plasma
  Plasma (physics)
  In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
  
  processes, including nonlinear processes, that govern the generation of plasma plumes? What are the precursor phenomena in the late afternoon F region
  F region
  The F region of the ionosphere is home to the F layer of ionization, also called the Appleton layer, after the English physicist Edward Appleton. As with other ionospheric sectors, 'layer' implies a concentration of plasma, while 'region' is the area that contains the said layer...
  
  that control whether or not an F-region
  F region
  The F region of the ionosphere is home to the F layer of ionization, also called the Appleton layer, after the English physicist Edward Appleton. As with other ionospheric sectors, 'layer' implies a concentration of plasma, while 'region' is the area that contains the said layer...
  
  plume will be generated after sunset
  Sunset
  Sunset or sundown is the daily disappearance of the Sun below the horizon in the west as a result of Earth's rotation.The time of sunset is defined in astronomy as the moment the trailing edge of the Sun's disk disappears below the horizon in the west...
  
  ?
- Daytime Valley echoes (or so-called 150 km echoes). What are the physical mechanisms causing them? (still a puzzle
  Puzzle
  A puzzle is a problem or enigma that tests the ingenuity of the solver. In a basic puzzle, one is intended to put together pieces in a logical way in order to come up with the desired solution...
  
  after more than 40 years!).
- E region: What are the nonlinear plasma
  Plasma (physics)
  In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
  
  physics
  Physics
  Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
  
  processes that control the final state of the equatorial electrojet
  Equatorial electrojet
  The equatorial electrojet is a narrow ribbon of current flowing eastward in the day time equatorial region of the Earth's ionosphere. The abnormally large amplitude of variations in the horizontal components measured at equatorial geomagnetic observatories, as a result of EEJ, was noticed as early...
  
  instabilities? To what extent do these instabilities affect the conductivity of the E region, and by extension, the conductivity of the auroral zone E region, where similar, but stronger and more complicated, instabilities exist?
- Neutral atmosphere
  Atmosphere
  An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
  
  dynamics. What are the tidal components at low latitudes for the different seasons and altitudes? How strong are the wind shear
  Wind shear
  Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...
  
  s in the mesosphere
  Mesosphere
  The mesosphere is the layer of the Earth's atmosphere that is directly above the stratosphere and directly below the thermosphere. In the mesosphere temperature decreases with increasing height. The upper boundary of the mesosphere is the mesopause, which can be the coldest naturally occurring...
  
  ? What are the characteristics of gravity wave
  Gravity wave
  In fluid dynamics, gravity waves are waves generated in a fluid medium or at the interface between two media which has the restoring force of gravity or buoyancy....
  
  s? Can we see evidence of lower atmosphere gravity wave
  Gravity wave
  In fluid dynamics, gravity waves are waves generated in a fluid medium or at the interface between two media which has the restoring force of gravity or buoyancy....
  
  coupling with the ionosphere
  Ionosphere
  The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...
  
  ?
- Meteor
  METEOR
  METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...
  
  physics
  Physics
  Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
  
  . Where are the meteoroids coming from? What are the mass
  Mass
  Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
  
  and size of the meteoroids? What is the equivalent visual magnitude of meteors detected at JRO? Can we use meteor
  METEOR
  METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...
  
  echoes to diagnose the atmosphere
  Atmosphere
  An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
  
  /ionosphere
  Ionosphere
  The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...
  
  at altitudes where they occur?

Coherent scatter echoes

Echoes Echo (phenomenon) In audio signal processing and acoustics, an echo is a reflection of sound, arriving at the listener some time after the direct sound. Typical examples are the echo produced by the bottom of a well, by a building, or by the walls of an enclosed room and an empty room. A true echo is a single...					Abbr.	Altitude (km)	Time of the day	Strength above ISR (dB)
Equatorial Electrojet Equatorial electrojet The equatorial electrojet is a narrow ribbon of current flowing eastward in the day time equatorial region of the Earth's ionosphere. The abnormally large amplitude of variations in the horizontal components measured at equatorial geomagnetic observatories, as a result of EEJ, was noticed as early...	EEJ	95-110 90-130	Daytime Daytime (astronomy) On Earth, daytime is roughly the period on any given point of the planet's surface during which it experiences natural illumination from indirect or direct sunlight.... Night Night Night or nighttime is the period of time when the sun is below the horizon. This occurs after dusk. The opposite of night is day... time	30-60 20-50
150 km echoes	150 km	130-170	Daytime Daytime (astronomy) On Earth, daytime is roughly the period on any given point of the planet's surface during which it experiences natural illumination from indirect or direct sunlight....	10-30
Neutral atmosphere Atmosphere An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...	MST	0.2-85	All day	30-50
Meteor METEOR METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision... -head	Head	85-130	All day	20-40
Non-specular meteor METEOR METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...	Non-specular	95-115	All day	20-50
Specular meteor METEOR METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...	Specular	80-120	All day	30-60

Non-conventional Studies

Besides the ISR and CSR observations, the main JRO system has been used as radio telescope

Radio telescope

A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...

, a VHF heater

Ionospheric heater

An ionospheric heater is an array of antennas which are used for heating the ionosphere, and which can create artificial aurora.- Current facilities :...

, and planetary radar. As radio telescope

Radio telescope

A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...

the main array has been used to study the Sun

Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

, radio star

Star

A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

s (like Hydra), magnetosphere

Magnetosphere

A magnetosphere is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the intrinsic magnetic field of a planet or similar body. Earth is surrounded by a magnetosphere, as are the other planets with intrinsic magnetic fields: Mercury, Jupiter,...

synchrotron radiation

Synchrotron radiation

The electromagnetic radiation emitted when charged particles are accelerated radially is called synchrotron radiation. It is produced in synchrotrons using bending magnets, undulators and/or wigglers...

, Jupiter

Jupiter

Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

radiation

Radiation

In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...

. In the 1960s JRO was used as to study Venus

Venus

Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...

and the surface of the Moon

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

and more recently the Sun

Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

. Recently, the equatorial electrojet

Equatorial electrojet

has been weakly modulated using JRO as a VHF heater

Ionospheric heater

An ionospheric heater is an array of antennas which are used for heating the ionosphere, and which can create artificial aurora.- Current facilities :...

to generate VLF waves.

Summary of Scientific Contributions and Milestones (since 1961)

1961. First observations of incoherent scatter echoes. First ISR in operation.
1961-63. Explanation of the physical processes behind the Equatorial electrojet plasma irregularities (Farley-Buneman instability.)
1962. First temperatures and composition measurements of the equatorial ionosphere.
1963 First electron density measurements of the equatorial Magnetosphere (the highest from ground based measurements even now).
1964.
- First VHF radar echoes from Venus.
- 1964. Discovery of the so-called 150 km echoes. The physical mechanisms behind these echoes are still (as of August 2008) a mystery.
1965. VHF radar measurements of the Moon’s surface roughness. Test run and used by NASA in 1969 for the Apollo 11 with Neil Armstrong knew he was going to tread.
1965-69. Development of Faraday rotation and double pulse techniques. Jicamarca is the only ISR that uses this technique in order to obtain absolute electron density measurements in the ionosphere.
1967. Application of a complete theory about the incoherent spread that includes the effects of collisions between ions and the presence of the magnetic field. Gyro Resonance experiment that verified the complete theory of incoherent scatter.
1969. Development of the pulse-to-pulse technique to measure ionosphere Doppler shifts with very good rpecision. Later, the same technique was applied to Meteorological radars.
1969-72. First measurements of the zonal and vertical equatorial ionospheric drifts.
1971. Development of the radar interferometry technique to measure size and location of the echoing region.
1972-74. Development of the MST (Mesosphere, Stratosphere, Troposphere) radar to measure winds and clear air turbulence. Smaller versions of this type of radars are called wind profilers.
Since 1974. Promotion and participation in international rocket campaigns to study atmospheric and ionospheric irregularities. JRO measurements complement the in-situ measurements perform with rockets launched from Punta Lobos, Peru.
1976. Explanation of the physics behind spread F irregularities
1981-82 Improvement of the radar interferometry technique to measure the zonal drifts of ionospheric irregularities (EEJ and ESF).
1987.
- Development of the Frequency Domain Interferometry (FDI) technique that allows measurements of fine altitude structure of echoes.
- 1987. Dr. Tor Hagfors, former JRO Director, received the URSI Balthasar van del Pol Gold Medal, for Contributions to radar engineering and the theory and experimental development of the incoherent scatter techniques”
Since 1991. Development of the radar Imaging technique by Peruvian scientists and US colleagues. This technique permits the observation of fine angular structure inside the beam, and therefore discriminate between time and space ambiguities.
1993. Installation of the first MST radar in the Antarctica.
1994. First observations of Polar Mesosphere Summer Echoes (PMSE) in the Antarctica and discovery of a significant asymmetry with respect to Arctic echoes.
1996. Prof. Donald T. Farley, former JRO Director and Principal Investigator, received the URSI Appleton Prize for “Contributions to the development of the incoherent scatter radar technique and to radar studies of ionospheric instabilities”.
1997. First VHF radar on board of a scientific ship (BIC Humboldt), which has allowed the study of the PMSE in different Antarctic latitudes.
1999. Dr. Ronald F. Woodman, former JRO Director, received the URSI Appleton Prize for “Major contributions and leadership in radar studies of the ionosphere and neutral atmosphere”.
2000. Radar technique to “compress” antennas, using binary phase modulation of the antenna modules
2001. First electron density measurements of electrons between 90 and 120 km of altitude using a small bistatic radar system.
2002.
- First observation of pure two stream E region irregularities during counter electric field conditions.
- Jicamarca 40th Anniversary Workshop.
Since 2003. Improved perpendicular to the magnetic field observations, accompanied by refinements in theory and computations, to measure simultaneously drifts and electron densities.
2004.
- Unambiguous measurements of the ESF spectra in the topside using aperiodic pulsing.
- Discovery of 150 km echoes using beams pointing away from perpendicular to the magnetic field.
2005. First E region zonal wind profiles from Equatorial electrojet echoes.
2006. Multi-radar observations of EEJ irregularities: VHF and UHF, vertical and oblique beams, and radar imaging.
2007. Identification of sporadic meteor populations using 90 hours of JRO’s meteor head echoes.
2008.
- First ISR full profile measurements of the equatorial ionosphere.
- First observation of meteor shower from meteor-head echoes.
2009. Installation of a Fabry–Peort Interferometer at JRO (MeriHill Observatory).

JRO Directors and Principal Investigators

JRO Directors
- 1960 -1963, Dr. Kenneth Bowles
  Kenneth Bowles
  Dr. Kenneth L "Ken" Bowles is best known for his work in initiating and directing the UCSD Pascal project, when he was a professor of Computer Science at the University of California, San Diego .- Education :Bowles received his PhD under Prof...
  
  (Ph.D., Cornell University
  Cornell University
  Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
  
  )
- 1964-1967, Dr. Donald T. Farley (Ph.D., Cornell University
  Cornell University
  Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
  
  )
- 1967-1969, Dr. Tor Hagfors
  Tor Hagfors
  Tor Hagfors was a Norwegian scientist, radio astronomer, radar expert and a pioneer in the studies of the interactions between electromagnetic waves and a plasma. He was one of several theorists who developed the theory underlying incoherent scattering in the early 1960s.Tor Hagfors was born in...
  
  (Ph.D., Stanford University
  Stanford University
  The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
  
  )
- 1969-1974, Dr. Ronald Woodman (Ph.D., Harvard University
  Harvard University
  Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
  
  )
- 1974-1977, Dr. Carlos Calderón (Ph.D., Darmouth College)
- 1977-1980, Dr. Pablo Lagos (Ph.D., Massachusetts Institute of Technology
  Massachusetts Institute of Technology
  The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...
  
  )
- 1980-2000, Dr. Ronald Woodman (Ph.D., Harvard University
  Harvard University
  Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
  
  )
- 2001–present, Dr. Jorge L. Chau (Ph.D., University of Colorado
  University of Colorado at Boulder
  The University of Colorado Boulder is a public research university located in Boulder, Colorado...
  
  )
JRO Principal Investigators
- 1979-2003, Prof. Donald T. Farley (Ph.D. Cornell University
  Cornell University
  Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
  
  )
- 2004–Present, Prof. David L. Hysell (Ph.D. Cornell University
  Cornell University
  Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
  
  )

Other ISRs in Wikipedia

EISCAT
EISCAT
EISCAT is an acronym for the European Incoherent Scatter Scientific Association. It operates three incoherent scatter radar systems, at 224 MHz, 931 MHz in Northern Scandinavia and one at 500 MHz on Svalbard, used to study the interaction between the Sun and the Earth as revealed by disturbances in...
Arecibo Observatory
Arecibo Observatory
The Arecibo Observatory is a radio telescope near the city of Arecibo in Puerto Rico. It is operated by SRI International under cooperative agreement with the National Science Foundation...
Millstone Hill Observatory
Millstone Hill Observatory
Millstone Hill Observatory is a Massachusetts Institute of Technology atmospheric sciences research centre in Westford, Massachusetts.- External links :* http://www.haystack.edu/atm/mho/index.html...

External links

Jicamarca Radio Observatory official site
Instituto Geofisico del Peru
JRO's news
JRO databases
Upper Atmosphere research at Cornell University
List of Publications Related to JRO
Satellite Image
Jicamarca Movies
- Scatter Radar: Space Research from the Ground, 1963 From NBS available via amazon also downloadable from Internet Archive
  Tells the story of Jicamarca Observatory, new National Bureau of Standards facility near Lima
  Lima
  Lima is the capital and the largest city of Peru. It is located in the valleys of the Chillón, Rímac and Lurín rivers, in the central part of the country, on a desert coast overlooking the Pacific Ocean. Together with the seaport of Callao, it forms a contiguous urban area known as the Lima...
  
  , Peru
  Peru
  Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
  
  , and its fascinating new research projects. Jicamarca, largest institution of its kind in the world, uses a 22 acre antenna
  Antenna (radio)
  An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
  
  , probes the upper atmosphere
  Atmosphere
  An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
  
  to measure electron densities
  Electron density
  Electron density is the measure of the probability of an electron being present at a specific location.In molecules, regions of electron density are usually found around the atom, and its bonds...
  
  , makes observations of planets, and studies solar coronas
  Corona
  A corona is a type of plasma "atmosphere" of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph...
  
  and solar gases. Presents in a travelogue-like sequence, the search for a site for the Observatory
  Observatory
  An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed...
  
  near the magnetic equator, watches construction go forward in the arid Jicamarca Valley at the foot of the Andes
  Andes
  The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
  
  , and, throughout, observes the cooperation of the Peruvian people and of the Instituto Geofisico del Peru, famous and historic ally-in-science of the National Bureau of Standards. The scatter radar technique is explained in simple animation sequences: high frequency radio waves penetrate the ionosphere
  Ionosphere
  The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...
  
  ; free electron
  Electron
  The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
  
  s in the upper atmosphere
  Atmosphere
  An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
  
  respond by oscillating and scattering
  Scattering
  Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more localized non-uniformities in the medium through which they pass. In conventional use, this also includes deviation of...
  
  their energy incoherently; the ultra-powerful Jicamarca antenna picks up this faint incoherent scatter
  Incoherent scatter
  Incoherent scattering is a type of scattering phenomenon in physics, which may involve various particles, such as neutrons or photons.One application is a ground-based technique for studying the Earth's ionosphere. A radar beam scattering off electrons in the ionospheric plasma creates an...
  
  . Analysis of this new data, yielding information heretofore concealed, provides the basis for calling this new technique "space research from the ground." From the National Institute of Standards and Technology
  National Institute of Standards and Technology
  The National Institute of Standards and Technology , known between 1901 and 1988 as the National Bureau of Standards , is a measurement standards laboratory, otherwise known as a National Metrological Institute , which is a non-regulatory agency of the United States Department of Commerce...
  
  .

Incoherent Scatter Radars around the world

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.