New camera may capture distant images without long lens

April 17, 2017

Houston, Apr 17: Scientists, including one of Indian origin, have developed a unique camera that can capture detailed images of distant objects without using a long lens, an advance that could lead to telescopes that are less bulky. The system known as SAVI – for “Synthetic Apertures for long-range, subdiffraction-limited Visible Imaging” – does not need a long lens to take a picture of a faraway object, researchers said.The prototype built by researchers reads a spot illuminated by a laser and captures the “speckle” pattern with a camera sensor.

cam

The prototype built by researchers reads a spot illuminated by a laser and captures the “speckle” pattern with a camera sensor.

Raw data from dozens of camera positions is fed to a computer programme that interprets it and constructs a high-resolution image.Researchers including those from Rice University in the US, built and tested the device that compares interference pat terns between multiple speckled images. Like the technique used to achieve the “Matrix” special effect, the images are taken from slightly different angles, but with one camera that is moved between shots instead of many fired in sequence. The prototype only works with coherent illumination sources such as lasers.

However, it is a step toward a SAVI camera array for use in visible light, researchers said. The speckles serve as reference beams and essentially replace one of the two beams used to create holograms, researchers said. When a laser illuminates a rough surface, the viewer sees grain-like speckles in the dot, as some of the returning light scattered from points on the surface has to go farther and throws the collective wave out of phase. The texture of a piece of paper – or even a fingerprint -is enough to cause the effect.

“Today, the technology can be applied only to coherent (laser) light,” said Ashok Veeraraghavan of Rice University.”That means you cannot apply these techniques to take pictures outdoors and improve resolution for sunlit images -as yet,” Veeraraghavan said.”With a traditional camera, the larger the physical size of the aperture, the better the resolution,” he said.

“If you want an aperture that is half a foot, you may need 30 glass surfaces to remove aberrations and create a focused spot.
This makes your lens very big and bulky,” he added. SAVI"s “synthetic aperture” sidesteps the problem by replacing a long lens with a computer programme the resolves the speckle data into an image, researchers said.

“You can capture interference patterns from a fair distance,” Veeraraghavan said. The research was published in the journal Science Advances.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
March 15,2020

Cybercriminals continue to exploit public fear of rising coronavirus cases through malware and phishing emails in the guise of content coming from the Centers for Disease Control and Prevention (CDC) in the US and World Health Organisation (WHO), says cybersecurity firm Kaspersky.

In the APAC region, Kaspersky has detected 93 coronavirus-related malware in Bangladesh, 53 in the Philippines, 40 in China, 23 in Vietnam, 22 in India and 20 in Malaysia. 

Single-digit detections were monitored in Singapore, Japan, Indonesia, Hong Kong, Myanmar, and Thailand. 

Along with the consistent increase of 2019 coronavirus cases comes the incessant techniques cybercriminals are using to prey on public panic amidst the global epidemic, the company said in a statement. 

Kaspersky also detected emails offering products such as masks, and then the topic became more commonly used in Nigerian spam emails. Researchers also found scam emails with phishing links and malicious attachments.

One of the latest spam campaigns mimics the World Health Organisation (WHO), showing how cybercriminals recognise and are capitalising on the important role WHO has in providing trustworthy information about the coronavirus.

"We would encourage companies to be particularly vigilant at this time, and ensure employees who are working at home exercise caution. 

"Businesses should communicate clearly with workers to ensure they are aware of the risks, and do everything they can to secure remote access for those self-isolating or working from home," commented David Emm, principal security researcher.

Some malicious files are spread via email. 

For example, an Excel file distributed via email under the guise of a list of coronavirus victims allegedly sent from the World Health Organisation (WHO) was, in fact, a Trojan-Downloader, which secretly downloads and installs another malicious file. 

This second file was a Trojan-Spy designed to gather various data, including passwords, from the infected device and send it to the attacker.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
February 25,2020

Tokyo, Feb 25: Japan's Chitetsu Watanabe, recognized at 112 years as the oldest man in the world, has passed away 11 days after he received the Guinness World Record certificate, his family said on Tuesday.

Watanabe died on Sunday night, Efe news reported.

He received the official certificate on February 12 at a nursing home in Joetsu in Niigata prefecture, where he resided.

Soon after being certified as the oldest man, he began to experience a lack of appetite and respiratory problems, the wife of his eldest son told public broadcaster NHK.

Born on March 5, 1907 in a family of farmers, Watanabe moved at the age of 20 to Taiwan, where he worked at a sugar refinery for 18 years before returning to Japan after the end of World War II.

A fan of calligraphy, custard and ice cream, Watanabe told the Guinness team that the key to his long life was laughter.

He was recognized as the oldest male in the world following the deaths in 2019 of German Gustav Gerneth (in October), aged 114 years, and Japan's Masazo Nonaka (in January), at the age of 113, three months older than the German.

It remains to be seen who will be recognized after the death of Watanabe, the only male on the list drawn up by the Gerontology Research Group of the 30 oldest people in the world.

Japan has among the highest life expectancy in the world and the number of centenarians in the country has crossed 71,000, according to the latest government figures.

Since 2000, the number of centenarians censored has quintupled, raising concern for the economic outlook and future workforce of the country - where the birthrate is on a downward trend.

Out of these, 88 per cent are women.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
January 4,2020

Washington D.C: One of the greatest spectacles of modern art is still thriving in the Australian outback as confirmed by satellite imagery of NASA. The Marree Man is a massive geoglyph depicting an aboriginal hunter, that spans over 2.6 miles in the Southern Australian region.

Discovered by a pilot in 1998, its origin still remains a mystery even to this date.

The Marree Man was given a new lease of life in 2016 when a group of people from the neighboring town of Marree plowed its lines to avert its fading due to erosion.

After NASA shared the image of the art-work that was taken in June, the efforts of the good samaritans turned out to be a total success, reported CNN Travel.

The restoration team believes that the refurbished Marree Man would last longer than its original version.

According to NASA, "They [the team] created wind grooves, designed to trap water and encourage the growth of vegetation. They hope that eventually, the man will turn green."

In a previous article, CNN reported that an entrepreneur by the name of Dick Smith took upon himself to unravel the geoglyph's mystery in 2016. His team combed through all the available evidence but couldn't find anything conclusive.

In 2018 he even offered a 5,000 Australian dollar reward for anyone who knows the identity of its creator.

Nobody turned up with an answer but it was speculated that unknown artist lives in Alice Springs or even might be an American.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.