Jicamarca Radio Observatory: 50 years of scientific and engineering achievements Jorge L. Chau, David L. Hysell and Marco A. Milla Radio Observatorio de Jicamarca, Instituto Geofísico del Perú, Lima
Outline Introduction Current capabilities Operational Modes Examples Scientific achievements Radio Science Radio Science Cluster of Instruments LISN FPI Network Magnetometers AMISR-7 at JRO
Jicamarca Radio Observatory The first ISR built for that purpose The only one in equatorial latitudes The largest and most powerful
Jicamarca Main Features Built in 1961 Antenna of 300 m x 300 m 50 MHz (Bragg wavelength = 3 m) 2 polarizations (linear, circular or elliptical) 3 TXs of 1.5 MW each (4 th being finished) Multiple RX capability (up to 16 channels) ±3 degrees steerability around on-axis Beam switching is done manually
Antenna group in action Connections have to be changed manually.
Other antennas & radar systems
Jicamarca main modes of operation Incoherent scatter modes (1000 h/year) Perpendicular Modes Oblique Modes Multi-beam: Oblique + Perpendicular Coherent scatter modes (4000 h/year) JULIA JULIA-Imaging MST Other modes Passive radio Heating at 50 MHz Planetary radar (Moon, Venus, Sun, ) Meteors
Multi-beam ISR: Oblique + Perpendicular Oblique: Two txs, two polarizations, NS quarters Perpendicular: One tx, two polarizations, EW quarters
New ISR mode: EW-Drifts + Faraday N E West beams East beams Perpendicula r to B Perpendicula r to B On-Axis (U-pol) Parallel to B On-Axis (D-pol) Parallel to B West & East: One TX, two polarizations, EW quarters On-Axis: Two TXs, two polarizations, NS quarters
August 2011 campaign - Vertical Drifts
August 2011 campaign - Zonal Drifts
August 2011 campaign - Ne densities
JULIA Mode: Equatorial Irregularities 1500 ESF and EEJ East Quarter EEJ (Oblique Yagis) ESF and EEJ East Quarter 200 500 100 1500 ESF and EEJ West Quarter EEJ (COCO) 150 km echoes (Main vertical) EEJ (COCO) ESF and EEJ West Quarter 200 500 100 0 6 12 18 24 ESF: Equatorial Spread F (nightime) 150-km echoes: Daytime EEJ: Equatorial Electrojet (all day)
A typical day over Jicamarca
A typical night
JULIA/Imaging: ESF example
JULIA/Imaging: Valley example
Scientific Achievements: Publications + Ph.D. Students > 700 Publications > 65 Ph.D. Thesis
Scientific Achievements: Radio Science Equatorial aeronomy discoveries (many first) Climatology of vertical and zonal drifts Topside exploration Understanding most equatorial ionospheric irregularities EEJ (Farley, Balsley, Fejer, Kudeki, Hysell, Woodman, ) ESF (Farley, Woodman, Hysell, Kudeki, ) 150-km irregularities (Balsley, Kudeki, Chau) Meteor irregularities (Kudeki, Chau, Woodman)
Scientific Achievements: Radio Science Pulse-to-pulse drift mode Multi-pulse mode Spectral drift mode Alternating codes Full profile inversion Multi-beam mode and inversion Interferometry MST Pulse compression Frequency domain Interferometry Spaced antenna Radar Imaging Antenna compression Bistatic Faraday mode Aperiodic pulsing
Cluster of Instruments for Equatorial and Low-latitude Observations (CIELO) LISN (C. Valladares, Boston College) Magnetometer chain (O.Veliz, IGP) Digisonde (B. Reinish, U. Mass. Lowell) Tristatic HF Doppler Radar (G. Crowley, ASTRA) Beacon Rxs (P. Bernhardt, NRL) New VIPIR at JRO (J. Makela/E. Kudeki, UIUC) (soon) Mini JULIA (J. Urbina, PSU) (2012?) Optics
JRO & Cluster of instruments Instrument Parameter Region Time Coverage Annual Coverage ISR MST JULIA Ne, Te, Ti, Vz, Vx, % U,V,W Irregularity intensity, Vz, Vx Regional Coverage Ionosphere 24 1000 hours JRO Troposphere, Stratosphere, Mesosphere 24 (T,S), daytime (M) > 10 days JRO Ionosphere 24 4000 hours JRO JULIA-150 Vz Ionosphere Daytime 150 days JRO FPI (AQP, SOFDI, MRH) Magnetometers (JRO, LISN) U,V, Tn Bottom F region Nighttime Daytime (SOFDI) Vz Ionosphere Daytime 365 days > 100 days Peru 77 o, 75 o, 69 o, 56 o West LISN GPS TEC, scintillations Ionosphere 24 365 days South America Ionosondes (JRO, LISN) TEC, scintillations Ionosphere 24 365 days 77 o W, 69 o W JASMET-Meteors U, V Mesosphere 24 Campaigns JRO, Piura, HYO (*)
LISN headquarters at Jicamarca Instruments: VIPIR ionosondes GPS receivers Magnetometers
LISN GPS + Database http://lisn.igp.gob.pe/station s/
Network of magnetometers in Peru Work in progress! http://jro.igp.gob.pe/database/magnetometer/html/magdata.htm
Magnetometers made at Jicamarca 1) 25m cable 2) Control and acquisition unit 3) Magnetic sensor 4) Output conector Specifications Total range : +/- 75000 nt 3 Dynamic ranges - Rango 1X : +/- 2500 nt - Rango 2.5X : +/- 1000 nt - Rango 10X : +/- 250 nt Sensitivity : 2.5mV/nT Resolution : 0.1 nt Accuracy : 0.25% Supply voltages : 12 Vdc/ 220Vac Current : +320 ma Output voltage : +/- 2.5 V full scale Digital output : USB
Optical Activities in Peru FPI Network Jicamarca Optical Observatory (MRH, Clemson) (Upgraded) Arequipa (A3O, Clemson) Nazca (NZK, Clemson) (New) SOFDI (Huancayo, NJIT, Clemson) (daytime operations) Airglow imager (OH, UIUC) Images need to be analyzed. High-time and high-angular resolution camera for meteor observations (SWRI)
AMISR-7 at JRO N
AMISR-7: System Description AMISR = Advanced Modular Incoherent Scatter Radar Transmit freq : 430MHz Transmit Peak Power : 112kW Transmit average power <= 11.2kW (10% Duty Cycle) Transmit pulse width : 1ms 2ms Antenna : crossed dipole array (circular pol.). 7 panels of 32 elements (3.5m. x 2m.)=49m 2 Receiver front end: low noise transistor amplifier on each element. Receiver back end : digital receiver PC level boards Antenna Configuration (8x1) EW Wide Beam
JULIA-AMISR-7 Interleave EEJ Experiments) 110 100 VHF Yagi 53ºW 110 100 VHF Yagi 0º 110 100 UHF AMISR 20ºW Type 1 EEJ Echoes 110 100 UHF AMISR 0º Mar 12 th, 2005 13:30 LT 12 Jan 29 th, 2005 15
AMISR-7 EEJ Multibeam Observations 435 East West Power Asymmetry Stronger West Echoes Balsley[1970] For more details on the EEJ asymmetry see Hysell et al, 2007
AMISR-7 Spread F Detection IPP=1000km,Tx = 100km, Duty Cycle =10%, FFT = 16 points
AMISR-7 ESF: VHF vs. UHF (1) JULIA BT-ESF
AMISR-7 ESF: VHF vs. UHF (2) AMISR-7 BT-ESF UHF ESF echoes are also overspread. Although range aliasing could be also used, contrary to EEJ, ESF echoes occur at different ranges between 200 and 800 kms. Pulse-to-pulse Doppler has been obtained from a double-pulse experiment (τ=144 km)
AMISR-7 ESF: VHF vs. UHF (3) JULIA BT-ESF Plume
AMISR-7 ESF: VHF vs. UHF (4) AMISR-7 BT-ESF Plume
AMISR-7 Tropospheric Winds
AMISR-7 Nighttime EEJ Observations
AMISR-7 Counter EEJ Observation 110 100 90 AMISR Vertical JULIA Oblique Wide Beam
AMISR-7 Meteor Detection Meteor trail observed with AMISR Jun 17th, 2005 [05:01:51 05:01:55]