Jicamarca Antenna Arrays: Systems and Science Ronald F. Woodman Instituto Geofisico del Peru

COCO-Hysell Mattresses Yagi array COCO-100 SOUSY Main Bistatic Tx Digisonde Tx JRO Arrays

Bistatic System for E region Density Measurements [Hysell and Chau, 2001, Shume et al. 2005]

Swartz, 03/11/7 64 th s Imaging at Jicamarca (2) 2D Antenna Configuration Module Hysell 4 1/256 th ’sTx on North and South quarters

AMISR System at JRO N

IS Antenna & Science 3-4 MW, 50MH, 300X300m, 2 polarizations, perp. to B

Jicamarca antenna pointing patterns

l/4 l/2

L1 L2 TX1 TX2 Tx110111<f Tx20111 PolRCLC2xL22xL1 2xL< q l/4

JRO Modes ISR Coherent Scatter Radar Equatorial Electrojet F-Dispersa 150 Km. echoes PEME Neutral turbulence

ISR Theory ( )

ISR example (1) Oblique mode Hybrid 1 It combines the traditional Faraday Double Pulse mode with alternating code mode. Allowing use of the available duty cycle and therefore better measurements and higher altitudinal coverage than before! Note: There are no E region measurements!

ISR example (3) Perpendicular Mode East-West Drift

ISR example (2) Oblique mode Hybrid 2: Long Pulse + Faraday

Coherent scatter with the large array (imaging)

MST Spectra (from Woodman [2002])

CSR MST (1): ST Winds days

MST Winds

ESF echoes (from Woodman and Chau [2001])

Slit-camera Analogy and Problems used with permission In some applications like races it is useful In many other applications it provides misleading results: Slow structures are stretch out Fast-moving structures are compressed. In general, it is difficult to discriminate space- time features.

Interferometry A B / P/ P f

Interferometry at Jicamarca (3) Main Interferometry Configuration for EEJ and ESF Tx on North and South quarters Rx on West and East quarters

Interferometry at Jicamarca (2) Measurements of Magnetic Field Inclination Using Incoherent scatter theory, combined with N-S Interferometer, Woodman [1971] was able to tome measure the inclination of the magnetic field above Jicamarca with 1 min of arc accuracy. At the time, models were off by ~1 o.Woodman [1971] [e.g. Woodman, 1971]Woodman, 1971

Woodman, 1971

Interferometry at Jicamarca (4) ESF and EEJ Interferometry Two quarter antennas for rx in the East- West direction. Vertical drift from first moment. Zonal drift from the cross-correlation angle between antenna pairs. [e.g. Kudeki et al., 1981]Kudeki et al., 1981 [e.g. Farley et al., 1981]Farley et al., 1981

Interferometry at Jicamarca (6) Aspect Sensitivity Configuration Receive signal on Various 64 th s Receive common Signal in 1/64 th Transmit on East and West Quarters [e.g. F. Lu, 2005; Ph.D. Thesis]

Interferometry at Jicamarca (10) Meteor-heads: Where do they come from? Most meteors come from the Apex direction. The dispersion around the Apex is ~18 o transverse to Ecliptic plane, and ~8.5 o in heliocentric longitude. Both in the Earth initial frame of reference. These features have been observed at different seasons, without no significant change on the population as function of season, e.g., November 2002 February 2003 June 2003 [from Chau and Woodman, 2004]Chau and Woodman, 2004

(from Woodman [1997])

Butler Matrix Butler and Lowe, 1961 FFT Algorithm Cochran et al., 1967

Swartz, 03/11/7 64 th s Antennas for Aperture Synthesis Imaging (Lots of Baselines !) Module Hysell 4 1/256 th ’sTx on North and South quarters

CSR Radar Imaging (5): EEJ at Twilight [from Chau and Hysell, 2004]

Imaging at Jicamarca (10): 3D Imaging – Lower Atmosphere Tropospheric Experiments Not much gain in information is obtained by using more than 3 antennas, with the “narrow” field of view employed (4 o and 8 o beam width for tropospheric and stratospheric images, respectively). Stratospheric Experiments Receiving Configuration [from Chau and Woodman, 2001]Chau and Woodman, 2001 [from Woodman and Chau, 2001]Woodman and Chau, 2001

Implementation -Antenna Codes

Coherent scattering and smaller radars and arrays

ESF and EEJ East Quarter ESF and EEJ West Quarter ESF and ESF East Quarter ESF and EEJ West Quarter 150 km echoes (Main vertical) EEJ (Oblique Yagis) EEJ (COCO) EEJ (COCO) CSR-JULIA: Multimode Ionospheric Observations “Jicamarca Unattended Long term Investigations of the Atmosphere” [Balsley, 1993] JULIA concept: “Low-power and long-term measurements at Jicamarca”

CSR- JULIA: Parameters from ESF and 150- km echoes ESF: Interferometry150-km:Dual beam Under validation!

SOUSY Antenna Array

Distribution of the Antenna Array

Electrojet Trospheric –Stratospheric echoes Mesosphere 150km. echoes

Spread-F

F Region Incoherent scatter

Bistatic System for E region Density Measurements [Hysell and Chau, 2001, Shume et al. 2005]

Array patterns for Bistatic Prototype Array of four elements -Green: 5/2 λ spacing - Red: 3/2 λ spacing

[from Woodman and Chau, 2002] Counter Equatorial Electrojet Observations: Pure two-stream echoes

Yagi Array for narrow beam EEJ studies 16 5-element Yagis Yagi spacing: 5/2 λ EW alignment: Five main beams: -51,-23,0,23,51. West beams are selected by titlting 45 degrees the Yagis See good example of “pure two stream”, cosine dependence.

AMISR 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 : 1  s – 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 (Interleave EEJ Experiments) Frequency Dependency Effect Balsley and Farley[1971] Farley and Fejer[1975]

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