A Much Needed RADAR System



RADAR (Radio Detecting and Ranging), as the name mentions, it is a detection and ranging device which primarily uses Radio waves for the detection of objects and ranging of the distance, angle, and velocity of that object. The system emits radio waves and calculates the distance, angle, and velocity by studying the nature of the reflected waves. Talking about its origin, this kind of system was developed by different countries before and during World-War II.

The Radar system has been used to track movements of airplanes in an airport from the time it was invented. Nepal’s international airport, Tribhuvan International Airport (TIA) currently uses one RADAR system which is more than 18 years old.

However, TIA is currently in the process of installing 2 new radars. MSSR (Mode S Monopulse Secondary Surveillance Radar) on the TIA itself and a SSR (Secondary Surveillance Radar) in Bhattedanda. The work started in early 2013 and the project aims to finish the installation by late March 2016. But the finishing date is not so promising due to the recent earthquake.


The current radar in TIA works as both primary and secondary radar system; while functioning as a secondary radar system, it cannot detect an aircraft’s position when it is flying below 5,000 feet due to hills and mountains. The plane crashes of 1992, Thai Airways on July and Pakistani airways on September highlighted the irregularities in the performance of the radar and the whole of the air traffic system.

During the peak season from September-November, TIA handles more than 70 international aircraft movements and 230 domestic flight movement per day. And the Civil Aviation Authority of Nepal (CAAN) expects the number of domestic and international air travelers to grow more than two folds by 2028 to 9.31 million compared to the numbers from 2011.

The expected increase in air traffic really underscores the necessity and importance of the new Radar systems that the TIA is currently installing. The TIA officials have informed about the necessary studies being conducted by the Japan International Cooperation Agency (JICA) under a team of 5 members lead by Hiroyuki Ueda, a senior advisor on transportation at JICA. The study is scheduled to finish on August 23rd, 2016.

The new radar system, once installed, will monitor both international and domestic flight movements. The combined system will work for en-route surveillance for up to 250 nautical miles. It can cover the entire country on the east, north, and south and up to Nepalgunj on the west side of the county.

Once the system is up and running it will have complete information on flight movement right from landing and taking off. It will also be able to track and share weather conditions, aircraft identity, and altitude among aircrafts. The use of the secondary radar in Bhattedanda which is at the higher altitude will ensure high performance to improve reliability and safety of the whole system.

It will provide accurate traffic data which updates in real time and doesn’t degrade with distance and terrain. The much-needed access to weather services, terrain maps, and flight information will be easily available to the pilots.

The radar would also assist a number of international routes like Trans-Himalaya 1 (Bangkok-Kolkata-Nepalgunj-Indek in Pakistan) and Himalaya 2 (Kathmandu-Bagdogra-Guwahati-Silchar-Imphal-Kunming).

The maintenance cost of presently operating Radar which is a whopping Rs.42.5 million. It is primarily because the parts used in ‘the more than 18 years old radar is hard to find and manufacture. The cost of maintenance will be reduced with the use of state-of-the-art MSSR and SSR as its parts are readily available.

Credit: Salin Maharjan

IOE, Thapathali campus
Bachelors in Mechanical, 4th year

Image Credit: BBC.UK
                          Kathmandu Post


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