Currently, LOFAR consists of 24 Core stations around Exloo, 14 Remote stations distributed over the Netherlands and 14 International stations distributed over Europe.
Core stations consist of 48 HBA's and 96 LBA's and a total of 48 digital Receiver Units (RCU's).
The HBA's are arranged in two 24-element fields with a diameter of 30.8 m each, straddling an 87 m diameter LBA field. The two 24-element fields can be used either as individual stations or their signals can be combined to form one station.
Although both the Dutch (core- and remote-) stations and the international stations have 96 dual polarization dipoles in their LBA field, the limited number of RCU's in the Dutch stations means that only 48 dual polarization (or 96 single polarization) signal paths can be used in the Dutch (core- and remote-) stations. The international stations do not have such a limitation.
The Dutch stations have the following options regarding the LBA configuration:
There are several options for configuring the HBA tiles. The majority of these configurations apply only to the core stations where two HBA fields are available.
- relevant for observations including core stations
- relevant for observations including remote stations
In addition, a special mode has been designed, designated by the "inner" tag (HBAzero_inner etc). This indicates that only the inner 24 tiles of the Remote stations are used, to match the configuration of each Core station HBA field. This tag does not operate on the international stations.