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

The first ISR built for that purpose The only one in equatorial latitudes The largest and most powerful

Jicamarca Radio Observatory

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 (4th 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

Perpendicular to B

Parallel to B

East beams

Perpendicular to B

Parallel to B

West beams

On-Axis (U-pol)

N

E

On-Axis (D-pol)

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

6 18 24 0 12

500

1500

1500

500

ESF and EEJ East Quarter

ESF and EEJ West Quarter

ESF and EEJ

East Quarter

ESF and EEJ

West Quarter 150 km echoes (Main vertical)

EEJ

(Oblique Yagis)

EEJ (COCO)

EEJ (COCO)

100

200

100

200

JULIA Mode: Equatorial Irregularities

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

Regional Coverage

ISR Ne, Te, Ti, Vz, Vx,

% Ionosphere 24 1000 hours JRO

MST U,V,W Troposphere, Stratosphere, Mesosphere

24 (T,S), daytime (M)

> 10 days JRO

JULIA Irregularity

intensity, Vz, Vx Ionosphere 24 4000 hours JRO

JULIA-150 Vz Ionosphere Daytime 150 days JRO

FPI (AQP, SOFDI, MRH)

U,V, Tn Bottom F region Nighttime

Daytime (SOFDI) > 100 days Peru

Magnetometers (JRO, LISN)

Vz Ionosphere Daytime 365 days 77o, 75o, 69o, 56o

West

LISN GPS TEC, scintillations Ionosphere 24 365 days South America

Ionosondes (JRO, LISN)

TEC, scintillations Ionosphere 24 365 days 77oW, 69oW

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/stations/

Network of magnetometers in Peru

http://jro.igp.gob.pe/database/magnetometer/html/magdata.htm

Work in progress!

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.)=49m2

• 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)

VHF Yagi 53ºW

VHF Yagi 0º

UHF AMISR 20ºW

UHF AMISR 0º 100

110

100

110

100

110

100

110

Jan 29th, 2005 12 15

Mar 12th, 2005 13:30 LT

Type 1 EEJ Echoes

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

100

110

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]