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1stspotter
9th Feb 2016, 18:24
Hello,
I have two questions on radar used for civil aviation air traffic control.

1. what is the difference between processed primary radar data and 'actually displayed data as seen by the air traffic controller?
I understand raw data is feed by multiple radar stations into a computer. The computer filters the noise. Then processed primary and processed secondary are mixed and presented to the ATC controller. What other processing or filtering is done?

2. what is the common method to store primary radar data? As raw or as processed and as displayed to the controller?


Are these depending on the vendor of the radar system?
1stspotter
9th Feb 2016, 20:35
Thx for the response.
Am I correct in my understanding that:

a radar station (either primary or secondary) transmits data to a computer. This computer converts the electronic pulse data/echo received from the radar antenna into a format called ASTERIX.
ASTERIX is the raw radar data and the primary usage is for archiving.

A filter, also a computer, filters the ASTERIX data and displays relevant info on the screen of the air traffic controller.
HEATHROW DIRECTOR
9th Feb 2016, 21:33
There is a fair amount on Google, for example Google "asterix radar data format".
1stspotter
10th Feb 2016, 15:23
Many thanks for the response so far.
This document titled Using *ASTERIX* in accident investigation explains that raw data is in fact ASTERIX data in inspector view.

Inspector view means the radar data is displayed to an aircrash investigator with no filtering at all.

http://www.isasi.org/documents/library/technical-papers/2011/schuurman/paper-isasi-farrell-schuurman-final-20110627.docx

I also understand that radar sensors (primary, secondary radar antennas) convert the target echo into ASTERIX message format. That is plain computer data. The UTC time is added and the data is sent over common IT-dataconnections to the air traffic control center.
There the data is processed by severall computers, archived, blended with for instance weather data and displayed to the controller

Hope I am correct