Report about MEXART and plans its use as a dedicated IPS system

Esmeralda Romero-Hernandez; Julio Mejia-Ambriz; J. Americo Gonzalez-Esparza

Institute of GeophysicsUNAM

MEXART is located in Michoacan, Mexico (19°48’ N 101°41’ W). It is a radio telescope dedicated to carry out observations of distant radio sources at 140 MHz. The aim is to perform solar wind studies using the Interplanetary Scintillation (IPS) technique. ANTENNA. The antenna is a plane array of 64 rows of 64 dipoles (4096 dipoles) aligned in E-W direction, covering 9600 m2 .

Technical Characteristics

Operation frequency: 139.65 MHz Basic element : dipole (λ= 2.15 m)Band width : 2 MHz Time constant: 47 msSampling rate: 20 msEfective area (1/4 of array): 1650 m2.

Effective area (full array): 6600 m2.

FWHM in E-W direction of beams: 1°

MEXART

In the website you can see real time transits:

This is a transit of some strongest radio sources detected by MEXART

Current configuration of MEXART

The technical team moved the half antenna (G1 and G2) to the other half (to G3 and G4). This process gave the opportunity to check and fix technical details.

The technical team bought new amplifiers wich are going to increase the signal-to-noise ratio in a 30 %.

At this moment, MEXART is operating with only a quater of the total array, but we are expecting that MEXART starts its operation with a half of the array on August.

• A preliminar analysis showed that signal-to-noise ratio has been increase significantly with this new configuration.

# of radio sources Observational minimum detectable flux (Jy)

¼ of array (2010) 67 18

¼ of array (2012) ~ 70 15

• MEXART is in the best step to make interplanetary scintillation observations.

• I will present the first analysis with this new configuration in AGU.

In conclusion …