1. Provides an overview of the main components in the simulator. Shows the relation between functions, data and user-inputs. The design is broken up into five sections:  Sky simulation module  Antenna simulation module  Weight generation module  Beamformer module  Metrics/visualisation module Plug-and-play interfaces (specified separately), using data checkpoints. User specifies simulation starting point.

2. Defines how sources, beams and antennas are positioned. Celestial coordinate system:  Generic equatorial system using unspecified epoch.  Celestial and geodetic longitude are equivalent.  Sources and beams are fixed in this frame. Local (horizontal) coordinate system:  Conventional horizontal system using azimuth and elevation.  Describes how the local sky above the station changes with time. Antenna coordinate system:  Two dimensional Cartesian axes to specify antenna positions relative to the station phase centre.

3. North (y) East (x)

4. Describes how the simulator is run by the user. Full simulation mode:  Realistic simulation of all required components used in an observation.  User specifies required start point of the simulation.  Optimised for data flow.  Gives the capability to form images of the model sky. Diagnostic mode:  Investigate and understand how various configurations and options affect the quality of the beams.  Provides more information about the operation of the simulator.  Restricts the options available to the user.  Visualise beam pattern in response to a given set of sources or weights.

5. Describes in (excruciating) detail the data transfer and interfaces between each major component of the simulator. Considers the amount and rate of data at each interface. Describes the structure of the data. Provides initial documentation for development of the simulator code. Defines the data formats to provides a flexible framework for future development.

6. Target completion by end of May 2008. Remaining components/documents:  User Interface Description All current documents in Basecamp. Wiki available from Monday 19 th May:  http://astrowiki.physics.ox.ac.uk/oskar/  Documents to be made available as soon as mini-review is passed. Also to be shared with Manchester University, Cambridge University, and interested parties.

7. Programming conventions. Simulator parallelism.