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{{Infobox Telescope}} |
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The '''Jicamarca Radio Observatory''' (JRO) is the [[equator]]ial anchor of the [[Western Hemisphere]] chain of [[Incoherent scatter|Incoherent Scatter]] [[Radar]] (ISR) observatories extending from [[Lima]], [[Peru]] to Søndre Strømfjord, [[Greenland]]. JRO is the premier scientific facility in the world for studying the equatorial [[ionosphere]]. The [[ |
The '''Jicamarca Radio Observatory''' (JRO) is the [[equator]]ial anchor of the [[Western Hemisphere]] chain of [[Incoherent scatter|Incoherent Scatter]] [[Radar]] (ISR) observatories extending from [[Lima]], [[Peru]] to Søndre Strømfjord, [[Greenland]]. JRO is the premier scientific facility in the world for studying the equatorial [[ionosphere]]. The [[observatory]] is about half an hour drive inland (east) from Lima and 10 km from the Central Highway ({{coord|11|57|05|S|76|52|27.5|W|}}, 520 meters ASL). The [[Magnetic dip|magnetic dip angle]] 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]]. The study of the equatorial [[ionosphere]] is rapidly becoming a mature field due, in large part, to the contributions made by JRO in [[radio]] [[science]].<ref name="AJ0N">{{cite journal |
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|author = Roald Steen, AJ0N |
|author = Roald Steen, AJ0N |
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|title = Ionospheric Research by Radar |
|title = Ionospheric Research by Radar |
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}}</ref> |
}}</ref> |
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JRO's main [[Antenna (radio)|antenna]] is the largest of all the [[incoherent scatter]] radars in the world. The main antenna is a cross-polarized square array composed of 18,432 half-wavelength [[dipole]]s occupying an area of approximately 300m x 300m. The main [[research]] areas of the observatories are: the stable equatorial ionosphere, ionospheric [[field aligned irregularities]], the dynamics of the equatorial neutral [[atmosphere]] and [[Meteoroid|meteor]] [[physics]]. |
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The |
The observatory is a facility of the Instituto Geofísico del Perú operated with support from the [[National Science Foundation|US National Science Foundation]] Cooperative Agreements through [[Cornell University]]. |
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==History== |
==History== |
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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 [[ |
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 [[Kenneth Bowles|Dr. Kenneth L. Bowles]], who is known as the “father of JRO”. |
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Although the last [[dipole]] was installed on April 27, 1962, the first [[incoherent scatter]] measurements at Jicamarca were made in early August 1961, using part of the total area projected and without the [[transmitter]]'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]] (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]]. Prof. Gordon invented the [[incoherent scatter]] [[radar]] technique in 1958. |
Although the last [[dipole]] was installed on April 27, 1962, the first [[incoherent scatter]] measurements at Jicamarca were made in early August 1961, using part of the total area projected and without the [[transmitter]]'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]] (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]]. Prof. Gordon invented the [[incoherent scatter]] [[radar]] technique in 1958. |
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==Facilities== |
==Facilities== |
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===Main |
===Main radar=== |
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JRO's main instrument is the [[VHF]] [[radar]] that operates on 50 [[Hertz|MHz]] (actually on 49.9 MHz <ref name="AJ0N"/>) and is used to study the [[physics]] of the equatorial [[ionosphere]] and neutral [[atmosphere]]. Like any other [[radar]], its main components are: [[Antenna (radio)|antenna]], [[transmitter]]s, receivers, radar controller, acquisition and processing system. The main distinctive characteristics of JRO's radar are: (1) the [[Antenna (radio)|antenna]] (the largest of all the ISRs in the world) and (2) the powerful transmitters. |
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==== Radar |
==== Radar components ==== |
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*[[Antenna (radio)|Antenna]]. The main antenna is a dual polarized antenna array that consists of 18,432 half-wavelength [[dipole]]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. |
*[[Antenna (radio)|Antenna]]. The main antenna is a dual polarized antenna array that consists of 18,432 half-wavelength [[dipole]]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. |
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*[[Transmitter]]s. Currently,{{when|date=August 2016}} JRO has three transmitters, capable of delivering 1.5 [[Watt|MW]] 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 (waves)|polarization]]: linear, circular or elliptical. |
*[[Transmitter]]s. Currently,{{when|date=August 2016}} JRO has three transmitters, capable of delivering 1.5 [[Watt|MW]] 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 (waves)|polarization]]: linear, circular or elliptical. |
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*Other. The remaining components of the radar are constantly being changed and modernized according to the [[technology]] 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 [[History of computing hardware|computer generations]] and systems have been used. |
*Other. The remaining components of the radar are constantly being changed and modernized according to the [[technology]] 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 [[History of computing hardware|computer generations]] and systems have been used. |
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==== Radar |
==== Radar modesofoperation ==== |
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The main radar operates in mainly two modes: (1) [[incoherent scatter]] [[radar]] (ISR) mode, and (2) coherent [[scattering|scatter]] (CSR) mode. In the ISR mode using the high power transmitter, Jicamarca measures the [[electron density]], [[electron]] and [[ion]] [[temperature]], ion composition and vertical and zonal [[electric field]]s in the equatorial [[ionosphere]]. Given its location and frequency of operation, Jicamarca has the unique capability of measuring the absolute [[electron density]] via [[Faraday rotation]], and the most precise ionospheric [[electric field]]s by pointing the beam [[perpendicular]] to the [[Earth's magnetic field]]. In the CSR mode the [[radar]] measures the echoes that are more than 30 [[Decibel|dB]] stronger than the ISR echoes. These echoes come from equatorial irregularities generated in [[troposphere]], [[stratosphere]], [[mesosphere]], [[equatorial electrojet]], [[E region|E]] and [[F region]]. Given the strength of the echoes, usually low [[Power (physics)|power]] transmitters and/or smaller antenna sections are used. |
The main radar operates in mainly two modes: (1) [[incoherent scatter]] [[radar]] (ISR) mode, and (2) coherent [[scattering|scatter]] (CSR) mode. In the ISR mode using the high power transmitter, Jicamarca measures the [[electron density]], [[electron]] and [[ion]] [[temperature]], ion composition and vertical and zonal [[electric field]]s in the equatorial [[ionosphere]]. Given its location and frequency of operation, Jicamarca has the unique capability of measuring the absolute [[electron density]] via [[Faraday rotation]], and the most precise ionospheric [[electric field]]s by pointing the beam [[perpendicular]] to the [[Earth's magnetic field]]. In the CSR mode the [[radar]] measures the echoes that are more than 30 [[Decibel|dB]] stronger than the ISR echoes. These echoes come from equatorial irregularities generated in [[troposphere]], [[stratosphere]], [[mesosphere]], [[equatorial electrojet]], [[E region|E]] and [[F region]]. Given the strength of the echoes, usually low [[Power (physics)|power]] transmitters and/or smaller antenna sections are used. |
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===JULIA |
===JULIA radar=== |
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JULIA stands for Jicamarca Unattended Long-term Investigations of the [[Ionosphere]] and [[Atmosphere]], a descriptive name for a system designed to observe equatorial [[Plasma (physics)|plasma]] irregularities and neutral atmospheric [[wave]]s for extended periods of time. JULIA is an independent [[Personal computer|PC]]-based data acquisition system that makes use of some of the exciter stages of the Jicamarca main [[radar]] along with the main [[Antenna (radio)|antenna]] array. In many ways, this system duplicates the function of the Jicamarca [[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 [[Watt|kW]] peak power pulsed transmitters driving a (300 m)^2 modular antenna array, JULIA is a formidable coherent [[scattering|scatter]] [[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. |
JULIA stands for Jicamarca Unattended Long-term Investigations of the [[Ionosphere]] and [[Atmosphere]], a descriptive name for a system designed to observe equatorial [[Plasma (physics)|plasma]] irregularities and neutral atmospheric [[wave]]s for extended periods of time. JULIA is an independent [[Personal computer|PC]]-based data acquisition system that makes use of some of the exciter stages of the Jicamarca main [[radar]] along with the main [[Antenna (radio)|antenna]] array. In many ways, this system duplicates the function of the Jicamarca [[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 [[Watt|kW]] peak power pulsed transmitters driving a (300 m)^2 modular antenna array, JULIA is a formidable coherent [[scattering|scatter]] [[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. |
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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. |
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. |
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===Other |
===Other instruments=== |
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Besides the main radar and JULIA, JRO hosts, and/or helps in the operations of, a variety of [[radar]]s as well as [[radio]] and [[Optics|optical]] [[scientific instrument|instruments]] to complement their main [[observation]]s. These instruments are: various ground-based [[magnetometers]] distributed through [[Peru]], a digital [[ionosonde]], many [[GPS]] receivers in [[South America]], an all-sky specular [[meteor]] [[radar]], a bistatic Jicamarca-[[Paracas Peninsula|Paracas]] CSR for measuring [[E region]] [[electron density]] profile, [[Scintillation (astronomy)|scintillation]] receivers in [[Ancón District|Ancon]], a [[Fabry–Pérot interferometer|Fabry–Perot Interferometer]] in [[Arequipa]], a small prototype of AMISR [[UHF]] [[radar]] |
Besides the main radar and JULIA, JRO hosts, and/or helps in the operations of, a variety of [[radar]]s as well as [[radio]] and [[Optics|optical]] [[scientific instrument|instruments]] to complement their main [[observation]]s. These instruments are: various ground-based [[magnetometers]] distributed through [[Peru]], a digital [[ionosonde]], many [[GPS]] receivers in [[South America]], an all-sky specular [[meteor]] [[radar]], a bistatic Jicamarca-[[Paracas Peninsula|Paracas]] CSR for measuring [[E region]] [[electron density]] profile, [[Scintillation (astronomy)|scintillation]] receivers in [[Ancón District|Ancon]], a [[Fabry–Pérot interferometer|Fabry–Perot Interferometer]] in [[Arequipa]], a small prototype of AMISR [[UHF]] [[radar]]. |
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==Main |
==Main research areas== |
||
The main research areas of JRO are the studies of: the equatorial stable ionosphere, the equatorial [[field aligned irregularities]], equatorial neutral [[atmosphere]] dynamics, and [[meteor]] [[physics]]. |
The main research areas of JRO are the studies of: the equatorial stable ionosphere, the equatorial [[field aligned irregularities]], equatorial neutral [[atmosphere]] dynamics, and [[meteor]] [[physics]]. |
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Here are some examples of the JRO topics |
Here are some examples of the JRO topics |
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==Non-conventional |
==Non-conventional studies== |
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Besides the ISR and CSR observations, the main JRO system has been used as [[radio telescope]], a VHF [[Ionospheric heater|heater]], and [[planetary radar]]. As [[radio telescope]] the main array has been used to study the [[Sun]], radio [[star]]s (like Hydra), [[magnetosphere]] [[synchrotron radiation]], [[Jupiter]] [[radiation]]. In the 1960s JRO was used as to study [[Venus]] and the surface of the [[Moon]] and more recently the [[Sun]]. Recently, the [[equatorial electrojet]] has been weakly modulated using JRO as a VHF [[Ionospheric heater|heater]] to generate [[VLF]] waves. |
Besides the ISR and CSR observations, the main JRO system has been used as [[radio telescope]], a VHF [[Ionospheric heater|heater]], and [[planetary radar]]. As [[radio telescope]] the main array has been used to study the [[Sun]], radio [[star]]s (like Hydra), [[magnetosphere]] [[synchrotron radiation]], [[Jupiter]] [[radiation]]. In the 1960s JRO was used as to study [[Venus]] and the surface of the [[Moon]] and more recently the [[Sun]]. Recently, the [[equatorial electrojet]] has been weakly modulated using JRO as a VHF [[Ionospheric heater|heater]] to generate [[VLF]] waves. |
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==Summary of |
==Summary of scientific contributions and milestones (since 1961)== |
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*1961. First observations of incoherent scatter echoes. First ISR in operation. |
*1961. First observations of incoherent scatter echoes. First ISR in operation. |
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**First VHF radar echoes from Venus. |
**First VHF radar echoes from Venus. |
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**1964. Discovery of the so-called 150 km echoes. The physical mechanisms behind these echoes are still (as of August 2008) a mystery. |
**1964. Discovery of the so-called 150 km echoes. The physical mechanisms behind these echoes are still (as of August 2008) a mystery. |
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*1965. VHF radar measurements of the |
*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. |
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*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. |
*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. |
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*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. |
*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. |
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*2000. Radar technique to “compress” antennas, using binary phase modulation of the antenna modules |
*2000. Radar technique to “compress” antennas, using binary phase modulation of the antenna modules |
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*2001. First electron density measurements of electrons between 90 and 120 km of altitude using a small bistatic radar system. |
*2001. First electron density measurements of electrons between 90 and 120 km of altitude using a small bistatic radar system. |
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*2002.[[File:jro oldtimers40th.jpg|right|thumb|300px|Peruvian and |
*2002.[[File:jro oldtimers40th.jpg|right|thumb|300px|Peruvian and foreign JRO staff from 1960to1969. Picture taken at JRO in May 2002 during the 40th Anniversary Workshop.]] |
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**First observation of pure two stream E region irregularities during counter electric field conditions. |
**First observation of pure two stream E region irregularities during counter electric field conditions. |
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**Jicamarca 40th Anniversary Workshop. |
**Jicamarca 40th Anniversary Workshop. |
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*2005. First E region zonal wind profiles from Equatorial electrojet echoes. |
*2005. First E region zonal wind profiles from Equatorial electrojet echoes. |
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*2006. Multi-radar observations of EEJ irregularities: VHF and UHF, vertical and oblique beams, and radar imaging. |
*2006. Multi-radar observations of EEJ irregularities: VHF and UHF, vertical and oblique beams, and radar imaging. |
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*2007. Identification of sporadic meteor populations using 90 hours of |
*2007. Identification of sporadic meteor populations using 90 hours of JRO's meteor head echoes. |
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*2008. |
*2008. |
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**First ISR full profile measurements of the equatorial ionosphere. |
**First ISR full profile measurements of the equatorial ionosphere. |
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*2011. Deployment of a Mobile Fabry-Perot Interferometer at Nasca. |
*2011. Deployment of a Mobile Fabry-Perot Interferometer at Nasca. |
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==JRO |
==JRO directors and principal investigators== |
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*JRO |
*JRO directors |
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** 1960–1963, [[Kenneth Bowles|Dr. Kenneth Bowles]] (Ph.D., [[Cornell University]]) |
** 1960–1963, [[Kenneth Bowles|Dr. Kenneth Bowles]] (Ph.D., [[Cornell University]]) |
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** 1964–1967, Dr. Donald T. Farley (Ph.D., [[Cornell University]]) |
** 1964–1967, Dr. Donald T. Farley (Ph.D., [[Cornell University]]) |
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{{commons category}} |
{{commons category}} |
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* [http://jro.igp.gob.pe/english Jicamarca Radio Observatory official site] |
* [http://jro.igp.gob.pe/english Jicamarca Radio Observatory official site] |
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* [https://archive. |
* [https://archive.today/19961224055602/http://geo.igp.gob.pe/ Instituto Geofísico del Perú] |
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* [http://jro.igp.gob.pe/newsletter JRO's news] |
* [http://jro.igp.gob.pe/newsletter JRO's news] |
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* [http://jro.igp.gob.pe/database/ JRO databases] |
* [http://jro.igp.gob.pe/database/ JRO databases] |
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[[Category:1961 establishments in Peru]] |
[[Category:1961 establishments in Peru]] |
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[[Category:Tourist attractions in |
[[Category:Tourist attractions in Lima Region]] |
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[[Category:Radio telescopes]] |
[[Category:Radio telescopes]] |
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[[Category:Astronomy in Peru]] |
[[Category:Astronomy in Peru]] |
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Jicamarca Radio Observatory - Lima, Peru
| |
Location(s) | Department of Lima, Peru |
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Coordinates | 11°57′05″S 76°52′28″W / 11.95139°S 76.87431°W / -11.95139; -76.87431 ![]() |
Organization | Geophysics Institute of Peru Cornell University National Science Foundation ![]() |
Wavelength | 6 m (50 MHz) |
Built | –1961 (–1961) ![]() |
Telescope style | radio telescope ![]() |
Collecting area | 82,944 m2 (892,800 sq ft) ![]() |
Website | jro![]() |
Location of Jicamarca Radio Observatory | |
![]() | |
The Jicamarca Radio Observatory (JRO) is the equatorial anchor of the Western Hemisphere chain of Incoherent Scatter Radar (ISR) observatories extending from Lima, Peru to Søndre Strømfjord, Greenland. JRO is the premier scientific facility in the world for studying the equatorial ionosphere. The observatory 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 / 11.95139°S 76.874306°W / -11.95139; -76.874306, 520 meters ASL). The magnetic dip angle 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. The study of the equatorial ionosphere is rapidly becoming a mature field due, in large part, to the contributions made by JRO in radio science.[1]
JRO's main antenna is the largest of all the incoherent scatter radars in the world. The main antenna is a cross-polarized square array composed of 18,432 half-wavelength dipoles occupying an area of approximately 300m x 300m. The main research areas of the observatories are: the stable equatorial ionosphere, ionospheric field aligned irregularities, the dynamics of the equatorial neutral atmosphere and meteor physics.
The observatory is a facility of the Instituto Geofísico del Perú operated with support from the US National Science Foundation Cooperative Agreements through Cornell University.
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, who is known as the “father of JRO”.
Although the last dipole was installed on April 27, 1962, the first incoherent scatter measurements at Jicamarca were made in early August 1961, using part of the total area projected and without the transmitter'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 (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. Prof. Gordon invented the incoherent scatter radar technique in 1958.
A few years later the National Science Foundation began partially supporting the operation of Jicamarca, first through NOAA, and since 1979 through 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 components have been replaced and modernized with “home made” hardware and software, designed and built by Peruvian engineers and technicians. More than 60 Ph.D. students, many from US institutions and 15 from Peru, have done their research in association with Jicamarca.
JRO's main instrument is the VHF radar that operates on 50 MHz (actually on 49.9 MHz [1]) and is used to study the physics of the equatorial ionosphere and neutral atmosphere. Like any other radar, its main components are: antenna, transmitters, receivers, radar controller, acquisition and processing system. The main distinctive characteristics of JRO's radar are: (1) the antenna (the largest of all the ISRs in the world) and (2) the powerful transmitters.
The main radar operates in mainly two modes: (1) incoherent scatter radar (ISR) mode, and (2) coherent scatter (CSR) mode. In the ISR mode using the high power transmitter, Jicamarca measures the electron density, electron and ion temperature, ion composition and vertical and zonal electric fields in the equatorial ionosphere. Given its location and frequency of operation, Jicamarca has the unique capability of measuring the absolute electron density via Faraday rotation, and the most precise ionospheric electric fields by pointing the beam perpendicular to the Earth's magnetic field. In the CSR mode the radar measures the echoes that are more than 30 dB stronger than the ISR echoes. These echoes come from equatorial irregularities generated in troposphere, stratosphere, mesosphere, equatorial electrojet, E and F region. Given the strength of the echoes, usually low power transmitters and/or smaller antenna sections are used.
JULIA stands for Jicamarca Unattended Long-term Investigations of the Ionosphere and Atmosphere, a descriptive name for a system designed to observe equatorial plasma irregularities and neutral atmospheric waves for extended periods of time. JULIA is an independent PC-based data acquisition system that makes use of some of the exciter stages of the Jicamarca main radar along with the main antenna array. In many ways, this system duplicates the function of the Jicamarca 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 peak power pulsed transmitters driving a (300 m)^2 modular antenna array, JULIA is a formidable coherent scatter 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.
Besides the main radar and JULIA, JRO hosts, and/or helps in the operations of, a variety of radars as well as radio and optical instruments to complement their main observations. These instruments are: various ground-based magnetometers distributed through Peru, a digital ionosonde, many GPS receivers in South America, an all-sky specular meteor radar, a bistatic Jicamarca-Paracas CSR for measuring E region electron density profile, scintillation receivers in Ancon, a Fabry–Perot InterferometerinArequipa, a small prototype of AMISR UHF radar.
The main research areas of JRO are the studies of: the equatorial stable ionosphere, the equatorial field aligned irregularities, equatorial neutral atmosphere dynamics, and meteor physics. Here are some examples of the JRO topics
Most common ionospheric/atmospheric coherent echoes | ||||
Echoes | Abbr. | Altitude (km) |
Time of the day |
Strength above ISR (dB) |
---|---|---|---|---|
Equatorial Electrojet | EEJ | 95-110 90-130 |
Daytime Nighttime |
30-60 20-50 |
150 km echoes | 150 km | 130-170 | Daytime | 10-30 |
Neutral atmosphere | MST | 0.2-85 | All day | 30-50 |
Meteor-head | Head | 85-130 | All day | 20-40 |
Non-specular meteor | Non-specular | 95-115 | All day | 20-50 |
Specular meteor | Specular | 80-120 | All day | 30-60 |
Besides the ISR and CSR observations, the main JRO system has been used as radio telescope, a VHF heater, and planetary radar. As radio telescope the main array has been used to study the Sun, radio stars (like Hydra), magnetosphere synchrotron radiation, Jupiter radiation. In the 1960s JRO was used as to study Venus and the surface of the Moon and more recently the Sun. Recently, the equatorial electrojet has been weakly modulated using JRO as a VHF heater to generate VLF waves.
{{cite journal}}
: CS1 maint: numeric names: authors list (link)