Hey Dick,
Found some info for you. You said;
However, I understand the Williamtown approach does not use mosaic or multi-radar tracking for aircraft that are flying close to the airfield. That’s why the thread is about Williamtown.
The ADATS Radar at all ADF bases is supplied by Raytheon. It is a multi tracking radar that displays the data on the screen using a mosaic picture of heaps of 4x4 Nm squares. Each tile recieves a No 1 radar feed and a secondary feed and can be a comination of MSSR, PSR or both. The computer decides which is the best data, does its techo thing and controller sees a nice return on screen.
This is from the Ratheon site.
Raytheon
Systems Ltd (RSL) - Electronics Systems, developed its
monopulse system in order to attack three problems that
were encountered with standard SSR. These shortcomings
became increasingly evident as air traffic
became denser and a heavier reliance was placed on
processed secondary radar data for air traffic control
(ATC) because it was able to provide positive height
and identity data.
The identified problems associated with the display
screen were 1) track wander, caused by signal interference,
2) garbling of close flying aircraft, making it
difficult to make separate identifications, and 3) false
targets caused by nearby objects reflecting the radar
signals. As a result of these problems, ATC operations
had to provide large aircraft flight path separations
which, in turn, meant longer times spent in loiter prior to
landing and higher fuel consumption.
The track wander problem was overcome by the SSR
monopulse system implementation concept. Instead of
ascertaining bearing by relying on the average of a
number of replies, the monopulse concept typically
needs only one pulse of a single transponder reply,
largely eliminating the risk of distortion from an
interruption of the reply pattern.
Worldwide Distribution
Raytheon claims that at least 30 countries utilize the SSR/MSSR systems. The following countries reportedly have
purchased some form of the Cossor SSR and/or MSSR:
Australia, Brazil, Canada, China, Cyprus, Denmark,
Greece
, Hong Kong, India, Jamaica, Norway, Oman, Saudi Arabia, Sweden, Switzerland, Trinidad/Tobago, United Kingdom, and the United States.
Guess what system the US are using for their upgrade !
The Standard Terminal Automation Replacement System (STARS) is a system jointly procured by the Federal Aviation Administration (FAA) and Department of Defense (DoD) to replace capacity-constrained, older technology systems at FAA and DoD terminal radar approach control facilities and associated towers. Raytheon Company is the prime contractor.
Perhaps they will use the same standards as we do and many others around the world.