#TACTICAL AIR NAVIGATION SYSTEM CODE#

CONSTANT TRANSPONDER DUTY-CYCLE Figure 2-1.-TACAN aircraft indication. A TACAN pulse pair generated by airborne or ground equipment is shown in figure 2-3. After the receiver decodes an interrogation, the encoder generates the necessary pulse pair required for the transponder’s reply. The purpose of this twin-pulse technique is to increase the average power radiated and to reduce the possibility of false signal interference. TACAN PULSE PAIRS TACAN transponders use twin-pulse decoders to pass only those pulse pairs with the proper spacing.

The frequency and identification code provide the geographic location of the transmitting beacon. The airborne DME then converts the roundtrip time to distance from the TACAN facility. After a 50-µsec delay, the transponder responds with a reply.

The airborne equipment generates timed interrogation pulse pairs that the surface TACAN system receives and decodes. However, TACAN beacon-transponders generate artificial replies instead of depending on natural reflection. The return signal (echo) of the radiated energy depends on the natural reflection of the radio waves. Radar-ranging determines distance by measuring the round-trip travel time of pulsed rf energy. TACAN PRINCIPLES The distance measuring concept used in TACAN equipment is an outgrowth of radar-ranging techniques. He or she can then either: (1) fly directly to that particular location, or (2) use the bearing and distance from a specific beacon to fix his or her geographic location. By using the TACAN equipment installed in the aircraft and TACAN ground equipment installed aboard a particular surface ship or shore station, a pilot can obtain bearing to and distance from that location. The other meter indicates the direction of flight, in degrees-of-bearing, to the geographic location of the surface beacon. One meter indicates, in nautical miles, the distance of the aircraft from the surface beacon. This information, as shown in figure 2- 1, is usually provided by two meters. TACAN is a polar-coordinate type radio airnavigation system that provides an aircrew with distance information, from distance measuring equipment (DME), and bearing (azimuth) information. We surveyed the Tactical Air Navigation System (TACAN) companies, and industry experts on this industry, involving the revenue, demand, product type, recent developments and plans, industry trends, drivers, challenges, obstacles, and potential risks. In electronics, it is usually used for plotting antenna directional patterns. The polar-coordinate system is a geometric system used to locate points on a plane. Depending on the installation, Air-to-Air mode may provide range, closure (relative velocity of the other unit), and bearing, though an air-to-air bearing is noticeably less precise than a ground-to-air bearing.CHAPTER 2 TACTICAL AIR NAVIGATION (TACAN) INTRODUCTION Before we begin discussing TACAN, you need to recall the definition of the polar-coordinate system. Capability was later upgraded to include an Air-to-Air mode (A/A) where two airborne users can get relative slant-range information. The typical TACAN onboard user panel has control switches for setting the channel (corresponding to the desired surface station's assigned frequency), the operation mode for either Transmit/Receive (T/R, to get both bearing and range) or Receive Only (REC, to get bearing but not range). The space shuttle is one such vehicle that was designed to use TACAN navigation (although it has since been upgraded with GPS as a replacement). Aircraft equipped with TACAN avionics can use this system for enroute navigation as well as non-precision approaches to landing fields. The DME portion of the TACAN system is available for civil use at VORTAC facilities where a VOR is combined with a TACAN, civil aircraft can receive VOR/DME readings. It is a more accurate version of the VOR/DME system that provides bearing and range information for civil aviation.

It provides the user with bearing and distance (slant-range) to a ground or ship-borne station. A tactical air navigation system, commonly referred to by the acronym TACAN, is a navigation system used by military aircraft.

#TACTICAL AIR NAVIGATION SYSTEM CODE#

Tactical air navigation system