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SSR antenna of Deutsche Flugsicherung at Neubrandenburg, in Mecklenburg/Western Pomerania Transponder in a private aircraft squawking 2000. Secondary surveillance radar (SSR) [1] is a radar system used in air traffic control (ATC), that unlike primary radar systems that measure the bearing and distance of targets using the detected reflections of radio signals, relies on targets equipped with ...
A solid state relay (SSR) is an electronic switching device that switches on or off when an external voltage (AC or DC) is applied across its control terminals. They serve the same function as an electromechanical relay , but solid-state electronics contain no moving parts and have a longer operational lifetime.
A primary radar or primary surveillance radar (PSR) is a conventional radar sensor that illuminates a large portion of space with an electromagnetic wave and receives back the reflected waves from targets within that space. The term thus refers to a radar system used to detect and localize potentially non-cooperative targets.
An ATC ground station consists of two radar systems and their associated support components. The most prominent component is the PSR. It is also referred to as skin paint radar because it shows not synthetic or alpha-numeric target symbols, but bright (or colored) blips or areas on the radar screen produced by the RF energy reflections from the target's "skin."
The klystron tube transmitter operates in the S-band between 2.5 and 2.9 GHz in circular polarization with a peak power of 1.3 MW and a pulse duration of 1 μs and pulse repetition frequency between 325 and 1200 pps. It can be switched to a second reserve frequency if interference is encountered on the primary frequency.
Traditionally, construction has made use of manual labor such as tradesmen and subcontractors for tasks such as the installation of prefabricated elements. [6] In the industrialization phase, construction uses manufacturing processes and technology to perform off-site prefabrication, assembling building components off-site rather than at the point of installation.
The functionality comprises decoding (one between many, ASTERIX data format), recording and computation of statistics. TRES (Trajectory Reconstruction and Evaluation Suite) is the core suite of SASS-C, carrying out the reconstruction of reference trajectories from the input data, and doing the evaluation of Surveillance constituent's performance.
In an effort to assist industry professionals with the selection of appropriate project delivery systems, construction management researchers have prepared a Procurement Method and Contract Selection Model, which can be used for high level decision making for construction projects on a case-by-case basis. [3]