PCAS Portable Collision Avoidance System
$528:- ($660:- incl. Swedish VAT) $1689:- ($2111.25 incl. Swedish VAT)
(Price will be invoiced in SEK, according actual rate USD-SEK, at time of order)
How PCAS Works
Here we are taking a look at the technology
behind PCAS and today's advanced collision avoidance systems.This
article is a brief overview off the technology behind traffic detection.
PCAS, which stands for Portable Collision Avoidance System, is a trademark
of Zaon Flight Systems for technology similar in function to TCAS (Traffic
and Collision Avoidance System). TCAS is the industry standard for commercial
collision avoidance systems. The original PCAS technology was developed in
1999. Now, the MRX/XRX line of collision avoidance systems incorporates the
fourth generation of PCAS technology. Through this technology, transponder-equipped
aircraft are detected and ranged, and the altitude is decoded. PCAS G4 technology
has advanced to the point that highly accurate range, relative altitude,
and quadrant direction can be accurately detected in a portable, all-in-one
cockpit
device.
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To explain how the system works, consider the following:
Step One
To start the cycle, an interrogation is sent out from ground-based RADAR stations and/or TCAS or other actively interrogating systems in your area. This signal is sent on 1030 MHz. For TCAS, this interrogation range can have a radius of 40 miles from the interrogation source. The Ground RADAR range can be 200 miles or more
Step Two
The transponder on any aircraft within range of the interrogation replies on 1090 MHz with their squawk code (known as Mode A) and altitude code (or Mode C). The altitude information is sent in an encoded format.
Mode S transponders also reply on this frequency, and encoded within the Mode S transmission is the Mode A (squawk) and Mode C (altitude) information.
Military aircraft also respond on this frequency but use a different transmission protocol (see Step 3).
Your aircraft’s transponder should also reply. However, the XRX unit watches for this signal and will not report it as a threat aircraft. The unit may use this information to establish base altitude for use in step 4.
Step Three
Any aircraft reply within the XRX detection window (maximum 6 miles) will be received. The range is computed, the altitude code is decoded, and the signal angle-of-arrival is determined. XRX will recognize interrogations from TCAS, Skywatch, and any other “active” system, military protocols, and Mode S transmissions.
Step Four
The altitude of the aircraft (in the example, 2500 ft.) is compared to your local altitude (i.e., 1500 ft.) and the relative altitude is calculated (i.e., 1000 ft. above you). With relative direction, altitude and range determined, XRX displays this information and stores it in memory.
Step Five
If additional aircraft are within detection range, the above process is repeated for each aircraft. The top threat is displayed on the left of the traffic screen, and on Screen A, the second and third threats are displayed on the right.
The greatest threat is determined by looking at aircraft within the detection
window you set up and comparing primarily the vertical separation (+/- relative
altitude), and secondarily the range to the aircraft currently being displayed.
XRX uses patent-pending SmartLogic algorithms to determine which of two or
more aircraft is a greater threat.