Introduction
The "PEST" vehicle used the unfortunate acronym resulting from "Plot Extraction System Test" - it was a mobile vehicle containing Locus 16 equipment and a 16" radar display displaying both analogue radar video and digital plot data from the CAA radar station under test.It was another small system produced by the Special ATC Systems Section of Airspace Control Division, Marconi Radar. The systems engineer responsible was Mike Darwent - his close attention to detail and stringent test specifications ensured that there were no significant problems in the implementation.
CAA Description
Here is the CAA description produced for its exhibit at Farnborough 1976:
'Plot Extraction' vehicle equipment
The vehicle contains equipment to enable engineers to examine various aspects of radar performance in order that they may
Evaluate improvements that might be possible as a result of developments in the radar field.
Optimise the performance of new equipment installed at CAA stations.
Ensure the continuing correct performance of radar equipment by carrying out routine checks.
The main equipment installed at present was provided by Marconi Radar Company Ltd, and consists of a single 16" radar display driven from a Locus 16 processor. It is capable of the simultaneous display of both analogue and digital radar information, and has full alpha-numeric display capability.
The analogue radar is displayed using a radar re-timing technique, thus allowing the digitally derived labels to be overlaid without loss of radar information. A strobe facility, actuated by a rolling ball, enables particular radar targets to be selected and tracked, and data relating to these targets may be recorded using a 'floppy' magnetic disc or punched paper tape, for later analysis. Alternatively, the data can be printed out immediately using a teletype and a line printer. Various general purpose programs may be entered into the processor for data collection and analysis applications, and it is envisaged that further programs will be written as necessary for specific tasks.
As configured at the present time, the main emphasis has been laid on facilities required in connection with the current programme, under which CAA is installing plot extractors at all its long range radar sites. Expansion to be included in the near future will include a plot extractor to facilitate improvements and modifications at various sites without the need to disturb the operational equipment.