<casaxml xsi:schemaLocation="http://casa.nrao.edu/schema/casa.xsd file:///opt/casa/code/tools/xml/casa.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://casa.nrao.edu/schema/psetTypes.html">
<tool module="imager" name="vpmanager">
<include>vpmanager_forward.h</include>
<include>vpmanager_private.h</include>
<shortdescription>Tool for specifying voltage patterns and primary beams</shortdescription>
The vpmanager tool serves to set up a list of primary beams or voltage patterns
(antenna responses) and then select in detail
which of them is used for which observatory.
The distinction of several antenna types for a given observatory (heterogeneous
Antenna responses can be selected from either internally
hard-coded ones, or response-groups defined via an AntennaResponses table, or
user-defined analytic primary beams.
Imaging and simulation routines pick up the selected response definitions
The vpmanager can also create a table with the
description of one or more voltage patterns (vp) or primary beams
(pb). There is a mapping between telescope name and the vp or pb
description. The vp description table can be read by imager's
<link anchor="imager:imager.setvp.function">setvp</link> method, which instantiates the
corresponding voltage patterns from the descriptions and applies them
The vpmanager tool is the CASA Python object which constitutes the
user interface to the VPManager C++ class. By default it is named "vp" in casapy.
The VPManager class is implemented as a singleton, i.e. internally there is only one instance
at all times. This instance accessed via the static VPManager::Instance() method. It is permanent
until casapy is exited and can be reinitialised via the VPManager::reset() method.
The vp tool connects to the single instance of VPManager.
All settings the user makes with the tool, have effect immediately and are then used
by all parts of CASA which access the VPManager class (i.e. eventually all imaging and simulation
The VPManager instance keeps a simple database of available antenna responses, the {\it vplist}.
This list is initialized at the startup of CASA or by calling the reset() method
of the class. In the vp tool, the reset call can be triggered using
In order to support heterogeneous interferometer arrays, VPManager permits the use
of {\it antenna types} in addition to observatory or {\it telescope} names.
For defining a simple response which is only spatially scaled by frequency but otherwise
constant, a simple call to the vp tool is sufficient, e.g.: