Friday, July 19, 2013

Applied sciences exclusive: Analyzing Pakistan's need for effective stealth countermeasures

by Faran Awais Butt via Terminalx. Shared under CC BY-NC-ND license 3.0.




Before I begin, I would like to familiarize the readers with two acronyms which I would use throughout this article: Electronic Counter Measure (ECM) and Electronic Counter Counter Measure (ECCM).

ECM is something that intends to disturb the normal working of a radar and ECCM refers to the efforts to overcome ECM. Jamming of the radar by noise or deception were the most notable amongst the ECMs but today, the radars of the world are under the threat of an even more sinister technology which is in possession of a very few countries; this technology, known as 'stealth', makes the target invisible to the radar. Stealth technology has brought up a revolution in the field of ECMs and has exposed the ineffectiveness of thousands of radars all across the world. The stealth aircrafts diffract and/or scatter very low power electromagnetic radiations owning to its special geometry and highly absorbent material. It is essential for the ground-based radars to have the capabilities of ECCM against stealth technology.

ECMs can be both seen and unseen. After World War II, there has been a significant research work on radar technology but as it progressed, its countermeasures also started to develop. The purpose of ECM is to make the radar less capable of detecting targets, deceiving the system and hence making it dysfunctional. It prevents the enemy radar from detecting the object. In reaction to ECM, there developed another form of electronic warfare which was developed as a reaction to ECM, known as ECCM i.e. electronic counter counter-measures of radar systems.

Electronic warfare is something in which every nation is trying to gain superiority at. There has been a rapid increase in sophistication of weapons in order to tackle the hostility of threats. ECCM is purely reactionary, that is, it has been developed in response to observed threats. If the ECM effects are observed in a specific system, a solution must be developed especially for a country like Pakistan which is under immense threat of this technology both from the western border (US, NATO forces) and India on the east.

Although stealth aircraft are in use and possess many qualities which make them superior to other fighter jets, however there still exist limitations to this technology. Many such aircraft are unstable and require a high-integrity sophisticated flight control and a fly-by-wire control system. The Radar Cross Section (RCS) of the aircraft is a parameter which dictates the detectability of the target. The greater the RCS, the easier it would be for the radar to detect it. Below 900 MHz, the target cross section increases exponentially. However, there is increased return from undesirable clutters. Shaping requirements have negative effect on the aerodynamics of the aircraft and hence they cannot be flown without a fly-by-wire control system. Hence, radar designers can exploit these vulnerabilities better than a mono-static radar since the bi-static RCS can be quite different depending upon target scattering characteristics.

The dramatic incident that took place on 2nd May 2011 at Abbottabad caused a humiliating disgrace to Pakistan when the United States' “modified” Blackhawk helicopters did a violation by covertly doing an operation at a strategically important location in Pakistan.

The report states that the latest stealth technology was used by the choppers employed in the raid. Helicopters with such technology are undetectable by ordinary radars.

The reports revealed that all of Pakistan Air Force's radar systems and technical monitoring assets were fully functional on 2nd May and no lapses of vigilance occurred that night on the part of the institution. This implies that there was lack of technology which resulted in the radars being unable to identify the incoming targets. It is evident thus, that radars are of no use if they cannot detect a target owing to ECM, which once again brings us to the conclusion that there needs to be an effective introduction of ECCMs into the system.

There is a global trend of using monostatic radars i.e. radars which have the same antenna which acts both as a transmitter/receiver and a duplexer which separates the signal. On the other hand, a bistatic radar is one in which there is a separate transmitter/receiver and the distance of the receiver should be considerable to the distance between radar and target. This trend needs to be changed for all the possible stealth-affected countries like Pakistan.

Stealth-oriented structures usually do not reflect the incoming wave in the same direction, rather they are absorbed and also scattered in different directions away from the radar.

These locations can be covered by use of multiple receivers at various locations. Pakistan should look for bistatic or a multi-static radar systems which have separated transmitters and receivers and whose receivers are located at a location comparable to the target’s distance.

Russia’s Sukhoi and Hindustan Aeronautics limited (HAL) are working on a project, 'Perspective Multi-role Fighter' (PMF), whose objective is to make Fifth Generation Fighter Aircraft (FGFA); these planes are expected to be in operation by 2015. India too, is working on autonomous unmanned combat air vehicles developed by the Defence Research & Development Organization (DRDO) for the Air Force.

Having already unveiled the J-20 Chengdu stealth fighter in January 2011, China is the only country which is developing two separate stealth fighters. The US is developing the F-35 Joint Strike Fighter in three versions; Russia is working on a single design, the 'PAK-FA', on which India is also collaborating. Separately, Japan is developing the ATD-X demonstrator.

Pakistan has a very fine air defence system against jamming techniques but there is a need to make efforts to overcome the threats of stealth. India has been working on stealth in collaboration with Russia where as Pakistan did not make any efforts to bring stealth technology to their system. Pakistan should seriously consider collaboration with China in the manufacturing of the'Mighty Dragon' J-20.

Efforts should be made by Pakistan to bring affordable stealth capabilities to their system. Although it must be acknowledged that this can take a lot of time. Pakistan should instead make efforts to build or design the counter to stealth system. The best radar that Pakistan has is the American TPS-77 which is a phased array radar. Phased array radars have many transmit/receive modules and such radars are very good in countering different types of noise jamming and to some extent, deception jamming. It also has a great deal of graceful degradation and room for modification according to situation.

Active phased array radars should be deployed since in such systems, there is a separate transmit/receive module which can be modified to have varied polarization, bandwidth and even operating frequency. Pakistan should look to work on active phased array systems in the radar factories at Kamra. Pakistan should also look to utilize radars operating on the lower side of L band of radar on the borders. Since building a multi-static radar approach could be very costly, we can either use modified radar warning receivers on a temporary basis or build a low cost multi-static radar system indigenously.

Microscopic sunburn


What a sun burn looks like under a microscope.

Thursday, June 20, 2013

In for the free ride

Remoras get free rides using sucking discs derived from dorsal fins by attaching to other marine animals or ship hulls. For those who know how inventing based on natural engineering has helped form optimal machines; apache helicopter based on dragon fly for example, can get significant inspiration for applied sciences.


Saturday, June 15, 2013

Artistic Engineering



Artistic Engineering: Glowstone mixed in with the cement or concrete to make this glow in the dark driveway.

Friday, June 7, 2013

First woman in space ready for ‘one-way flight to Mars'

Shared via Rianovosti.

 


STAR CITY, MOSCOW REGION, June 7 (RIA Novosti) – Valentina Tereshkova, the first woman in space, said Friday that she disapproved of space tourists and would be prepared to leave retirement to undertake a one-way trip to Mars, her favorite planet.

Tereshkova, 76, was speaking ahead of the 50th anniversary of her June 16, 1963, blastoff, which propelled her into the record books and made her one of the Soviet Union’s most feted astronauts.

“Of course, it’s a dream to go to Mars and find out whether there was life there or not,” Tereshkova said. “If there was, then why did it die out? What sort of catastrophe happened?”

While she said that she thought the first manned flight to Mars would be a suicide trip, she volunteered to take part. “I am ready,” she said.

Tereshkova spent three days orbiting the Earth in 1963 and is one of only three female Russian astronauts to have taken part in a space mission, compared with over 50 of their counterparts in the United States.

Not all aspects of modern space flight are to Tereshkova’s taste. She said the privilege of going into space should be reserved for scientists and professional astronauts, and not be available to the highest bidder.

There have been eight space tourists since 2001, with each cosmic jaunt costing upward of $20 million.

“Only specialists should be making space flights because, while there have been a lot of flights and more than 50 astronauts, there is still a lot that hasn’t been studied,” Tereshkova said. “But if they [the people going into space] are specialists, if they can bring some use working aboard a spaceship, then be my guest.”

Tereshkova was part of a small team of women assembled by the Soviet authorities as potential astronauts in the wake of the first manned space flight by Yury Gagarin in 1961, but she was the only one who actually went into space. The next Russian woman to do so, Svetlana Savitskaya, blasted off 19 years later, in 1982.

Tereshkova, whose call sign was "Seagull," also revealed a secret about her pioneering space flight: that a technical error almost precipitated disaster when she was about to re-enter the Earth's atmosphere.

On landing, Tereshkova said she was approached by Sergei Korolyov, the father of the Soviet space program, who addressed her as "my little seagull" and begged her not to reveal the mistake.

"So I kept the secret for exactly 30 years," Tereshkova said.

Sunday, June 2, 2013

Exclusive: Pakistan expresses interest in non-nuclear EMP weapons technology

by Zaki Khalid via Terminalx.



Well-informed sources say that Pakistani security officials have expressed interest in the research and development of non-nuclear EMP (electromagnetic pulse) weapons.

Sources privy to the development had earlier shared that a panel of Chinese and Russian experts had met in Moscow to discuss means of collaborating for a giant Asian EMP-shield ('umbrella') that would protect regional airspace, particularly that of Russia and China, from intruding systems.

In this context, Pakistani officials expressed their interest. It is expected that as previously, Pakistan will approach its counterparts in China to map a possible joint R & D venture.