GMRT ANTENNA UPGRADATION STATUS

Conventions used in above table:

 OFC – Optical Fibre Cable, LPF – Low Pass Filter, FE – Front End, NF – Notch Filter, Temp – Temperature monitoring, PM – Power Monitoring, SBF – Sub-Band Filter, NG – Noise Generator, Amp – Amplifire etc.

Upgradation jobs with respect to antennas :          ww  antennas with UPS  ww  antennas without UPS.  

                130MHz-260MHz -  Dual-Ring Feed @ 150MHz                        250MHz-500MHz - Cone-Dipole Feed @ 325MHz                550MHz-900MHz -Cone-Dipole Feed @ 610MHz

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  Antenna status as per  completion of up-gradation jobs :

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GWB (GMRT WIDE-BAND BACK-END) :

 This is the New Correlator Back-end at GMRT in the Broad-band RF Signal receiver chain.

 Broad-Band RF From Antenna is taken to the GAB (GMRT Analog backend) through upgraded Optical Fiber. All antennas can be configured  and monitored  at GAB, and out of which any 32 antennas with Broadband Feed and RF facilities listed above for 1pol or any 16 antennas with dual pol can be chosen for GWB.

 GWB-IV (version 4) is the latest release, It accepts 64 input connections. These 64 input connections can be configured as 32 antennas Dual polarization inputs. (either Total Intensity or Full Stokes).

This release supports, 400/200/100 MHz wide band observations with maximum16 K spectral channels can be configured. Also, 4 Beam selections including raw voltage and coherent de-dispersion pipeline are available for pulsar observations with varying beam integration values ( in ms). This release also supports multi-sub-array observations. Detailed release configuration of GWB is as in table below:

 GWB-IV supports various available modes for pulsar, continuum and line frequency observations. Best possible mode, depending on user requirement can be chosen using gwb4calculator.pl on astro8 machine.

    allant;cp 0;defs 0;suba 0;

  for more details please refer file - `lenyadri:/odisk/online1/INFO/GAB_ONLINE.SOP`

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MCM-4 ( FE Parameter control Unit) through online CDSETM4 (C02 and C05):

Antennas Central Square are enabled with MCM 4, to set upgraded FE parameters. The required command set has been modified and implemented by Mr. Jitendra. The SOP for issuing the Control command for FES parameters as follows:

 Add MCM-4 in 'online'

 use  'cdsetm4' for FES parameter setting

 'run fe4mcm' --To execute parameters setting

Please Ensure that now onwards for Central Square antenna all FES parameters ( walsh, noise and mcm) has to be executed using 'cdsetm4' only

  ** For 325 MHz : use broad-band feed instructions ad mentioned under Para A above.

  ** For Non Broad band antennas from User need to set Full Band settings, while doing observations with Sub-bands for Upgraded feed.

Notes :

• ●Dual Band observations (235 & 610) is not possible for antennas with 550-900 CDF at 610 FPS position is installed. 

• ●Antennas with new Broadband 150 MHz feed installed, 150 MHz and 235 MHz can be used with 150 MHz feed in focus and 150 MHz  RF and respective LO values for 150 MHz and 235 MHz frequency band observations. 

• ●Antennas those are not upgraded for 150 and upgraded for 610 MHz can not be used for 235 MHz observations. 

• ●Antennas those are upgraded for 150 and not upgraded for 610 MHz can not be used for 235 MHz observations. 

• ●Note : Satellite Notch Filter (230-275 MHz) Only In CH1 are putted in Rx Room in C06 and E02 Antenna. 

• ●To set 325 MHz Full band use RF= 325 in cdset1-4 or RF = 470 in cdsetm files. 

• ●Noise cal setttings will not work for antennas C04, C06, C10, W01, W04, W06, E02, E06, S02, S04 for Broad band Feed @ 325MHz (250-500MHz). 

• ●"Diesel Generator ON" alarm is enabled in the control room. Whenever a Diesel generator of any antenna(s) is running, control room will get an audio alarm with text message. Text message contains time, sub-array and antenna name. This alarm will works only for E04, E05, E06, W03, W04, W05, W06, S03, S04, S06.  

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Last Updated on 30th January 2018.

Email : nilesh@gmrt.ncra.tifr.res.in