EVN Observing Bands

The EVN observing frequencies depend upon the capabilites of the participating telescopes, but typically range from 1 GHz to 25 GHz. Fewer telescopes can observe at the higher frequencies (K-band) than at lower frequencies (L-band), and hence a subset of array is available depending upon chosen observing band. Wavelengths include: 1.3 cm, 5 cm, 6 cm and 21 cm.

The EVN has two main data recording modes:
Traditional Disk Recording VLBI Mode and
Real Time Correlation e-VLBI Mode

Disk Recording Mode

This is the tradiational method of operating VLBI whereby the data are recorded locally at each telescope on disk which are later delivered to JIVE for correlation. There are 3 sessions per year, each lasting approximately three weeks. The delivery of the data ranges from physically transporting disk-packs to JIVE in the Netherlands or, as is being adopted by an increasing number of observatories, over the internet from 'flex-buffs'. This method provides the largest observing bandwidth as the data transport need not happen in real time.

e-VLBI Real Time Mode

e-VLBI refers to the real-time correlation method of observing whereby the data are streamed directly from each telescope over optical fibres to JIVE for immediate correlation. This mode occurs one day per month and is useful if immediate results are required.

Observe with e-MERLIN+EVN

The EVN announces regular observing cycles (currently three times per year), inviting the astronomical community to propose new experiments. Inclusion of all of e-MERLIN's antennas within EVN observations requires a specific request in the EVN proposal.

For more information on how to observe using e-MERLIN within the EVN please visit the EVN website.