What is

Navigation & Surveillance systems
They are systems that determine the position, orientation, and velocity of objects.

we do:

We specialize in installation, configuration, and maintenance of the following systems:

Navigation & surveillance systems

1- ILS (instrument landing system)

ILS stands for Instrument Landing System and is a standard International Civil Aviation Organization (ICAO) precision landing aid that is used to provide accurate azimuth and descent guidance signals for guidance to aircraft for landing on the runway under normal or adverse weather conditions.

The ILS consists

The Localizer Receiver on the aircraft measures the Difference in the Depth of Modulation (DDM) of the 90 Hz and 150 Hz signals. for the localizer, the depth of modulation for each of the modulating frequencies is 20 percent.
The difference between the two signals varies depending on the position of the approaching aircraft from the centerline.

A Glideslope or Glidepath (GP) antenna array is sited to one side of the runway touchdown zone. The GP signal is transmitted on a carrier frequency between 329.15 and 335 MHz using a technique like that of the localizer.
The centerline of the glideslope signal is arranged to define a glideslope of approximately 3° above horizontal (ground level). The beam is 1.4° deep; 0.7° below the glideslope centerline and 0.7° above the glideslope centerline.

The connection between the aircraft’s position and these signals is displayed on the aircraft’s instrumentation, often as additional indicators in the heading indicator. The pilot attempts to maneuver the aircraft to keep these indicators centered as it approaches the runway.

The receiver in front of the array will receive both signals mixed. Using simple electronic filters, the original carrier and the two sidebands can be separated and resampled to extract the original amplitude modulated signals at 90 and 150 Hz. The instrument landing system (ILS) may also include high-intensity lighting at the end of the runways.

2- DVOR (Doppler VHF Omni Directional Range)

A DVOR (Doppler VHF Omni Directional Range) is a short/medium-range radio navigation system used to aid aircraft in determining their flight position and direction in relation to their destination using VHF (Very High Frequency) signals between 108.00 to 117.95 MHz sent from a radio beacon.

DVOR are an International Civil Aviation Organization (ICAO) standard navigational aid that assists aircraft in their approach by sending omnidirectional signals from ground radio beacons located at airports and runways. These signals are sent from transmitters located in a network of VOR stations.

These stations hold arrays (transmitters) that spin horizontally, sending out very high frequency (VHF) signals ranging from 108.00 to 117.95 MHz, when the receiving unit collects these radio signals (up to 200 miles from the transmitter), they can pinpoint their position and enable the aircraft to remain on course.

3- Distance Measuring Equipment (DME)

DME is radio navigation technology that measures the slant range (distance) between an aircraft and a ground station by timing the propagation delay of radio signals in the frequency band between 960 and 1215 megahertz (MHz), Line-of-visibility between the aircraft and ground station is required.

DME systems are used worldwide, using standards set by the International Civil Aviation Organization (ICAO), the European Union Aviation Safety Agency (EASA) and other bodies.

Some countries require that aircraft operating under instrument flight rules (IFR) be equipped with a DME interrogator.

While stand-alone DME transponders are permitted, DME transponders are usually paired with an azimuth guidance system to provide aircraft with a two-dimensional navigation capability.

A common combination is a DME collocated with a VHF omnidirectional range (VOR) transmitter in a single ground station.

When this occurs, the frequencies of the VOR and DME equipment are paired, such a configuration enables an aircraft to determine its azimuth angle and distance from the station.


A navigation system used by military aircraft. It provides the user with bearing and distance (slant-range or hypotenuse) to a ground or ship-borne station. This system can achieve a range of up to 740 km air-to-air and 600 km ground-to-air.


A system used by both civil and government aircraft.

It is an aeronautical radio navigation system that operates in a frequency range of 960-1215MHz.

It is a system that is functionally equivalent to the standard ICAO distance-measuring equipment (DME) but provides more functionality than the DME, namely the acquisition of almanac information.

The Tactical Air Navigation System (TACAN) also includes shipboard and air-to-air applications.

Besides range measurements, tactical air navigation also provides azimuth information.
For identification purposes, the Tactical Air Navigation Beacon (TACAN) transmits a Morse ID code, the identity tone is used on airborne responders to check if the correct beacon is providing range readings.


Is a short-range navigational aid. VORTAC provides both direction and distance information to the aircraft. Instead of having two separate ground stations VOR and TACAN, VORTAC combines both systems referred to as VORTAC.

The Rx and Tx ground station operate as follows:

The VOR operates in the VHF band from 108 - 118MHz.

It operates in the frequency band 960-1215 MHz.

Civil aircraft use the VOR as the Rx system while the DME interrogator is used as the Rx and Tx system.

Military aircraft use TACAN as the Rx and TX system.

The VORTAC system benefits from the VOR and TACAN systems by integrating both systems and benefiting from reduced maintenance and operational costs.


A radiolocation system that uses radio waves to determine the distance (ranging), angle (azimuth), and radial velocity of objects relative to the site.
It is used to detect and track aircraft, ships, spacecraft, guided missiles, and motor vehicles, and map weather formations, and terrain.

Radar consists of four main components:

A transmitter, which creates the energy pulse.

A transmit/receive switch that tells the antenna
when to transmit and when to receive the pulses.

An antenna to send these pulses out into the
atmosphere and receive the reflected pulse back.

A receiver, which detects, amplifies, and transforms the received signals into video format.

There are two types of radar systems:

1. Primary Radar:

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, it is specific to the field of air traffic control.

2. Secondary Radar:

It is a radar that works through transmitters of pulses from a ground station, and receivers attached to the aircraft to receive a series of wave pulses and decode them, and send these pulses as a response through one of the systems integrated on the aircraft, where these pulses are sent at different frequencies but are adjacent and the ground radar receives the response signal It determines the range and direction of the aircraft in a similar way to the primary radar.

7- Automatic Dependent Surveillance–Broadcast (ADS-B)

ADS-B is a performance-based monitoring technology that is more accurate than radar and consists of two different services:
(ADS – B Out) & (ADS – B In)

ADS-B is an advanced monitoring technology that combines an aircraft positioning source, avionics, and ground infrastructure to create a precise control interface between aircraft and the ATC control tower.