Simulating Various Arrays

The aim of this challenge is to repeat some of the challenges but "observing" with an instrument other than the WSRT. A python program is included which can generate antenna tables for many well know arrays, as well as any combination of the dishes contained in the included antenna data file.

This antenna table can then be used with makems to generate the measurement set. Instructions for getting makems are here: http://www.astron.nl/meqwiki/BuildingMakeMs

This program has only been tested with the version of pyrap from the oxford repository.

The mkant.py program uses pyrap to generate the antenna table. It gets its antenna information from the locations.dat file. You can look at the top of the program to see which arrays it has predefined. Otherwise you can make your own array from the dishes in the locations.dat file.

Some examples:

mkant.py VLAA_ANT VLAA

mkant.py EVN_ANT EVN

mkant.py LOFAR_ANT LOFAR_CORE_HBA

mkant.py MYARR_ANT "['EB', 'JB', 'MC', 'NT', 'TR']"

When you create your own arrays you use python list syntax. The locations file is based on data from the vlbi sched program. The existing Lofar stations have been added to the file as well as locations for WSRT antennas that were missing.

The makems program can be used to generate a MS as in SSSC1. The makems config file to be used should be renamed to makems.cfg and then makems run with no arguments. MakeMS only copies the locations of the antennas in the supplied table to the MS, so it can be replaced with the full antenna table if proper station names, mount, and dish size info is desired. eg:

rm -rf EVN1.MS/ANTENNA

cp -r EVN_ANT EVN1.MS/ANTENNA

Datasets can then be simulated as usual. The field size in the EVN image is 0.005 and 150 in the Lofar image.