Samsung Semi updated its last year's mobile products presentation talking about its recent CIS innovations and market shares:
Samsung CIS Slides
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Image Sensor Precautions
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Sony publishes a 2016 edition of its Quality and Reliability Handbook. Its section 5.1 talks about precautions when dealing with image sensors:
- Do not expose to ultraviolet rays, sunlight or other strong light for long periods. The transmittance and color characteristics of the on-chip lens and color filter may be affected.
- Avoid storing or using products at a high temperature or high humidity, as this may adversely affect the transmittance or color characteristics.
- The imaging characteristics may be affected by noise or other factors when strong electromagnetic waves or magnetic fields are approached during operation. Special care should be taken for CMOS image sensors as these are easily affected.
- Note that the image of CMOS image sensors may be affected by light leaking to the optical black when using an infrared cut filter that has transmittance in the near infrared range while shooting subjects with high luminance.
- Sony image sensor specifications do not assume use in environments with above-ordinary radiation levels.
- White pixels occur spontaneously in image sensors over time and due to cosmic radiation. White pixels that occur should be compensated using a white pixel compensation circuit.
Graphene Stretching Controls its Photoresponse
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Researchers from the University of Illinois at Urbana-Champaign have demonstrated a new approach to modifying the light absorption and stretchability of atomically thin two-dimensional (2D) materials by surface topographic engineering using only mechanical strain.
"We achieved more than an order-of-magnitude enhancement of the optical extinction via the buckled 3D structure, which led to an approximately 400% enhancement in photoresponsivity,” stated Pilgyu Kang, a postdoctoral research associate and first author of the paper, “Crumpled Graphene Photodetector with Enhanced, Strain-tunable and Wavelength-selective Photoresponsivity,” appearing in the journal, Advanced Materials. “The new strain-tunable photoresponsivity resulted in a 100% modulation in photoresponsivity with a 200% applied strain. By integrating colloidal photonic crystal—a strain-tunable optomechanical filter—with the stretchable graphene photodetector, we also demonstrated a unique strain-tunable wavelength selectivity.”
“This work demonstrates a robust approach for stretchable and flexible graphene photodetector devices,” SungWoo Nam, an assistant professor of mechanical science and engineering added. “We are the first to report a stretchable photodetector with stretching capability to 200% of its original length and no limit on detection wavelength. Furthermore, our approach to enhancing photoabsorption by crumpled structures can be applied not only to graphene, but also to other emerging 2D materials.”
"We achieved more than an order-of-magnitude enhancement of the optical extinction via the buckled 3D structure, which led to an approximately 400% enhancement in photoresponsivity,” stated Pilgyu Kang, a postdoctoral research associate and first author of the paper, “Crumpled Graphene Photodetector with Enhanced, Strain-tunable and Wavelength-selective Photoresponsivity,” appearing in the journal, Advanced Materials. “The new strain-tunable photoresponsivity resulted in a 100% modulation in photoresponsivity with a 200% applied strain. By integrating colloidal photonic crystal—a strain-tunable optomechanical filter—with the stretchable graphene photodetector, we also demonstrated a unique strain-tunable wavelength selectivity.”
“This work demonstrates a robust approach for stretchable and flexible graphene photodetector devices,” SungWoo Nam, an assistant professor of mechanical science and engineering added. “We are the first to report a stretchable photodetector with stretching capability to 200% of its original length and no limit on detection wavelength. Furthermore, our approach to enhancing photoabsorption by crumpled structures can be applied not only to graphene, but also to other emerging 2D materials.”
AR and VR Market Potential
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Statista quotes Goldman Sachs research predicting the industry reaching a value of $80 billion a year ($35 billion software and $45 billion hardware) by 2025, roughly the size of the desktop PC market today. The potential of AR/VR tech is extremely diverse:
Update: Re\code: AR startup Magic Leap publishes a patent on how AR will change a coffee drinking experience in the future.
Update: Re\code: AR startup Magic Leap publishes a patent on how AR will change a coffee drinking experience in the future.
Lytro Exits Consumer Camera Business
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Imaging Resource, DPReview: Lytro exits consumer light-field camera business, apparently due to the lack of the consumer interest. The company CEO Jason Rosenthal says in his blog post "While consumer Light Field cameras offered a number of true technological breakthroughs such as interactive 3D pictures, radical lens specs, and the ability to focus a picture after the fact we had a number of disadvantages as well including 4X larger file sizes and lower resolution in comparison to other similarly priced cameras. The cold hard fact was that we were competing in an established industry where the product requirements had been firmly cemented in the minds of consumers by much larger more established companies. This issue was compounded by the fact that the consumer camera market was declining by almost 35% per year driven by the surge in smartphone photography and changing consumer tastes."
The company's Vimeo video talks about its new focus on Immerge VR cinema production platform:
The company's Vimeo video talks about its new focus on Immerge VR cinema production platform:
Lytro Immerge from Lytro on Vimeo.
ON Semi, Omnivision Unveil Security Camera Sensors
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ON Semi presents AR0237, a 1/2.7-Inch 2.1MP 1080p60 sensor for security and surveillance applications. The sensor uses DR-Pix technology with Dual Conversion Gain pixel and supports line interleaved T1/T2 readout with HDR processing in ISP chip, among other features:
PRNewswire: OmniVision announces OV9755 CameraChip HD image sensor for mainstream security, smart home, and IP cameras. The power-efficient sensor is based on 3.75um OmniPixel3-HS pixel. The 3.75um pixel is said to enable best-in-class low-light performance at 43Ke-/lux-sec and less than 0.2 lux SNR1 (the luminance value for a signal to noise ratio of 1:1). The OV9755 is currently in volume production.
"According to a recent industry report, the global smart camera market for security and surveillance applications is expected to grow from $1.93 billion today to $3.06 billion by 2020, with CMOS sensor-based cameras leading the growth," said Chris Yiu, senior marketing manager at OmniVision.
Other Omnivision announcements are design wins in Tamron camera module with OIS for security and action cameras, featuring 1/3-inch 4MP OV4689, and HiSilicon IP camera reference design with 1/3-inch 1080p30 OV2718.
PRNewswire: OmniVision announces OV9755 CameraChip HD image sensor for mainstream security, smart home, and IP cameras. The power-efficient sensor is based on 3.75um OmniPixel3-HS pixel. The 3.75um pixel is said to enable best-in-class low-light performance at 43Ke-/lux-sec and less than 0.2 lux SNR1 (the luminance value for a signal to noise ratio of 1:1). The OV9755 is currently in volume production.
"According to a recent industry report, the global smart camera market for security and surveillance applications is expected to grow from $1.93 billion today to $3.06 billion by 2020, with CMOS sensor-based cameras leading the growth," said Chris Yiu, senior marketing manager at OmniVision.
Other Omnivision announcements are design wins in Tamron camera module with OIS for security and action cameras, featuring 1/3-inch 4MP OV4689, and HiSilicon IP camera reference design with 1/3-inch 1080p30 OV2718.
Unispectral Raises $7.5M
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Globes: Israeli startup Unispectral closed a $7.5M Series A funding round led by Jerusalem Venture Partners (JVP), Robert Bosch Venture Capital (RBVC), Samsung Catalyst Fund and The Tel Aviv University Technology Innovation Momentum Fund. This brings the money raised by the company to date to $8M.
The company is developing the next generation of digital cameras which will use hyper-spectral sensors for enhanced seeing and sensing capabilities.
The company says it aims to transform the four-decade standard of color sensing mechanisms in compact cameras. Its imaging technology is said to provide an unprecedented low light sensitivity and rich color, complemented by better resolution. Unispectral's hyper-spectral sensor will be applicable to a wide range of use cases such as wearables, digital health and medical imaging, Internet of Things, industrial and agriculture applications, and beyond. This breakthrough technology, backed by multiple patents, is said to be able to distinguish material properties in solids, liquids and gases.
The company's PCT patent application WO2014207742 "A SYSTEM AND METHOD FOR COLOR IMAGE ACQUISITION" by David MENDLOVIC and Ariel RAZ reveals its technology:
The company is developing the next generation of digital cameras which will use hyper-spectral sensors for enhanced seeing and sensing capabilities.
The company says it aims to transform the four-decade standard of color sensing mechanisms in compact cameras. Its imaging technology is said to provide an unprecedented low light sensitivity and rich color, complemented by better resolution. Unispectral's hyper-spectral sensor will be applicable to a wide range of use cases such as wearables, digital health and medical imaging, Internet of Things, industrial and agriculture applications, and beyond. This breakthrough technology, backed by multiple patents, is said to be able to distinguish material properties in solids, liquids and gases.
The company's PCT patent application WO2014207742 "A SYSTEM AND METHOD FOR COLOR IMAGE ACQUISITION" by David MENDLOVIC and Ariel RAZ reveals its technology:
Huawei P9 Features Dual Camera
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The newly announced Huawei P9 flagship smartphone features a dual camera based on Sony 12MP IMX286 sensors with 1.25um pixel pitch:
Ambarella S5 IP Camera SoC Delivers 4K 10-bit H.265 Video
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BusinessWire: Ambarella introduces the S5 SoC for 4K and multi-imager IP camera designs. The S5 offers 4K multi-exposure HDR fusion, 360° de-warp and ultra-low light processing. Maximum performance is 4Kp120 or 8Kp30 of H.264/AVC and 4Kp60 frames of H.265/HEVC, while supporting multi-streaming, rate control and transcoding functions. The S5 supports the high-quality Main10 HEVC Profile (10-bit H.265) and Ambarella’s SmartHEVC technology to reduce 4Kp30 video bitrates to between 512 Kbps and 4 Mbps. The S5 image sensor interface and its advanced 1-Gigapixel/s ISP can be configured as up to four independent sensor inputs to allow high resolution multi-imager cameras.
“The S5 will play a critical role in the industry’s shift to 4K and H.265," said Fermi Wang, President and CEO of Ambarella. "With it, our partners gain a leading-edge image processor that delivers low power consumption, superior image quality, smart H.265 compression and a powerful quad-core CPU.”
Ambarella low-power architecture combined with 14nm FinFET process enables 4Kp30 encoding, including DDR, at less than 1.4 Watts
“The S5 will play a critical role in the industry’s shift to 4K and H.265," said Fermi Wang, President and CEO of Ambarella. "With it, our partners gain a leading-edge image processor that delivers low power consumption, superior image quality, smart H.265 compression and a powerful quad-core CPU.”
Ambarella low-power architecture combined with 14nm FinFET process enables 4Kp30 encoding, including DDR, at less than 1.4 Watts
Omnivision Announces 2nd Generation RGB-IR Sensors
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PRNewswire: OmniVision announces the OV4686 and OV9756, two 1/3-inch RGB-Ir sensors that support dual band color filters instead of traditional mechanical rotary IR filters. Leveraging an innovative color array pattern, the OV4686 and OV9756 can capture high quality infrared images and video, even from long ranges, and bring superior color aliasing performance compared to previous generation offerings.
"Maintaining high quality images and color accuracy as lighting conditions change throughout the day is an essential capability for image sensors geared towards the security marketplace," said Chris Yiu, senior marketing manager at OmniVision. "By utilizing our second-generation RGB-Ir dual color band filter, the OV4686 and OV9756 sensors deliver excellent color performance and infrared imaging in a compact form factor well-suited for commercial and consumer applications such as smart doorbells and other IoT camera systems."
Built on a 2um OmniBSI-2 pixel, the OV4686 captures 1080p120 and 720p180 video. The OV9756 is based on 3.75um OmniPixel3-HS pixel and delivers 720p60 video. It also features low-power mode with system wake-up trigger functionality.
The OV4686 and OV9756 sensors are currently available for sampling and are expected to enter volume production in Q2 2016.
"Maintaining high quality images and color accuracy as lighting conditions change throughout the day is an essential capability for image sensors geared towards the security marketplace," said Chris Yiu, senior marketing manager at OmniVision. "By utilizing our second-generation RGB-Ir dual color band filter, the OV4686 and OV9756 sensors deliver excellent color performance and infrared imaging in a compact form factor well-suited for commercial and consumer applications such as smart doorbells and other IoT camera systems."
Built on a 2um OmniBSI-2 pixel, the OV4686 captures 1080p120 and 720p180 video. The OV9756 is based on 3.75um OmniPixel3-HS pixel and delivers 720p60 video. It also features low-power mode with system wake-up trigger functionality.
The OV4686 and OV9756 sensors are currently available for sampling and are expected to enter volume production in Q2 2016.
IHS: iPhone SE Cameras Cost $13.30
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BusinessWire: IHS iPhone SE teardown report estimates both front and rear camera module cost $13.30, out of $156.20 total BOM, or about 8.5% - about the same proportion as iPhone 4s cameras:
Record Arctic Warming
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On April 3rd, 2016, Arctic sea ice extent was at a record low for the time of the year, reports the National Snow and Ice Data Center (NSIDC).
The image below, created with an image from the JAXA site, gives an update on sea ice extent.
Besides sea ice extent, sea ice area is important. For more on what constitutes "ice-covered" and what is sea ice extent (versus sea ice area), see this NSIDC FAQ page.
Another measure is sea ice area. On April 2nd, 2016, Northern Hemisphere sea ice area was at a record low for the time of the year, reports the Cryosphere Today.
In 2015, there still was more sea ice area than there is now when it was half a month later (15 days) into the year. In 2012, there still was more sea ice when it was 25 days later in the year. In other words, sea ice area decline is almost one month ahead compared with the situation in 2012.
NSIDC scientist Andrew Slater has created the chart below of freezing degree days in 2016 compared to other years at Latitude 80°N. See Andrew's website and this page for more on this.
The Arctic has warmed more than elsewhere on Earth. Surface temperatures over the past 365 days were more than 2.5°C or 4.5°F higher than they were in 1981-2010.
The image below compares sea ice thickness on April 3rd for the years 2012, 2015 and 2016 (respectively the left, center and right panel).
The high temperatures that have hit the Arctic Ocean over the past 365 days make that the outlook for the sea ice in the Arctic this year is not good.
As illustrated by the image on the right, the current El Niño is still going strong, with temperatures above 100°F recorded in three continents.
The year 2016 is already shaping up as the warmest year on record by far.
Temperatures look set to soar over the coming months, over the Northern Hemisphere at large and over the Arctic in particular.
The image below shows that over a 90-day period from January 13, 2016, to April 11, 2016, most of the Arctic Ocean was more than 6°C (10.8°F) warmer than 1981-2011.
The DMI image below shows recent melting in Greenland up to April 11, 2016. Maps in the left panel show areas where melting has taken place on April 10 and April 11, 2016. The chart in the right panel shows 2016 melting (blue line), against the 1990-2013 average (the vertical axis reflects the percentage of the total area of the ice where the melting occurred).
As a recent study confirms, ice sheets can contain huge amounts of methane in the form of hydrates and free gas. Much methane can escape due to melting and fracturing during wild weather swings.
Rapid melting on Greenland looks set to continue. The forecast for April 12, 2016 (0000 UTC), on the right shows temperature anomalies at the top end of the scale (20°C or 36°F) over most of Greenland and Baffin Bay, while the Arctic as a whole is hit by a temperature anomaly of over 5°C (over 9°F), compared to 1979-2000.
Furthermore, ocean temperatures are currently very high. These high temperatures, together with the poor condition of the sea ice, make that chances are that the sea ice will be largely gone by September 2016.
The image on the bottom right shows sea surface temperature anomalies above Latitude 60°N on April 4, 2016.
The image below shows that, on April 7, 2016, sea surface in the Barents Sea was as warm as 10.1°C or 50.2°F, an anomaly of 9.4°C or 16.9°F from 1981-2011 (at the location marked by the top right green circle), while there were anomalies as high as 11.3°C or 20.3°F off the coast of North America (green circle bottom left).
The white line shows the approximate path of the cold exit current, while the red line shows the approximate path of the warm entry current.
The high temperatures in the Barents Sea give an indication of the ocean heat traveling toward the Arctic Ocean, while the high temperature anomalies off the east coast of North America give an indication of the heat that is building up there. Much of this heat will make its way to the Arctic Ocean over the coming months
In the Pacific, sea surface temperature anomalies from 1981-2011 were as high as 11.6°C or 20.8°F near Japan on April 11, 2016 (see image right), giving a further indication of the huge amount of additional heat that there now is in oceans on the Northern Hemisphere. The prospect is that temperatures will rise over the next few months to levels even higher than they were last year (see earlier post on temperatures in June 2015).
Sea ice acts as a buffer, absorbing heat and keeping the temperature of the water at freezing point. Without such a buffer, further heat will instead make that the temperature of the water will rise rapidly. Furthermore, less sea ice means that less sunlight gets reflected back into space and more sunlight instead gets absorbed by the Arctic Ocean.
These are just some of the many feedbacks that accelerate warming in the Arctic. Warm water reaching the seafloor of the Arctic Ocean can penetrate sediments that can contain huge amounts of methane in the form of hydrates and free gas, triggering abrupt release of methane in gigantic quantities, escalating into runaway warming, and subsequent destruction and extinction at massive scale.
On a 10-year timescale, the current global release of methane from all anthropogenic sources already exceeds all anthropogenic carbon dioxide emissions as agents of global warming; that is, methane emissions are more important than carbon dioxide emissions for driving the current rate of global warming.
Besides sea ice extent, sea ice area is important. For more on what constitutes "ice-covered" and what is sea ice extent (versus sea ice area), see this NSIDC FAQ page.
Another measure is sea ice area. On April 2nd, 2016, Northern Hemisphere sea ice area was at a record low for the time of the year, reports the Cryosphere Today.
In 2015, there still was more sea ice area than there is now when it was half a month later (15 days) into the year. In 2012, there still was more sea ice when it was 25 days later in the year. In other words, sea ice area decline is almost one month ahead compared with the situation in 2012.
NSIDC scientist Andrew Slater has created the chart below of freezing degree days in 2016 compared to other years at Latitude 80°N. See Andrew's website and this page for more on this.
The Arctic has warmed more than elsewhere on Earth. Surface temperatures over the past 365 days were more than 2.5°C or 4.5°F higher than they were in 1981-2010.
The image below compares sea ice thickness on April 3rd for the years 2012, 2015 and 2016 (respectively the left, center and right panel).
Sea ice thickness has fallen dramatically over the years, as illustrated by the image on the right, from NSIDC, showing Arctic sea ice age for the week from March 4 to 10, from 1985 to 2016.
The high temperatures that have hit the Arctic Ocean over the past 365 days make that the outlook for the sea ice in the Arctic this year is not good.As illustrated by the image on the right, the current El Niño is still going strong, with temperatures above 100°F recorded in three continents.
The year 2016 is already shaping up as the warmest year on record by far.
Temperatures look set to soar over the coming months, over the Northern Hemisphere at large and over the Arctic in particular.
The image below shows that over a 90-day period from January 13, 2016, to April 11, 2016, most of the Arctic Ocean was more than 6°C (10.8°F) warmer than 1981-2011.
As a recent study confirms, ice sheets can contain huge amounts of methane in the form of hydrates and free gas. Much methane can escape due to melting and fracturing during wild weather swings.
Rapid melting on Greenland looks set to continue. The forecast for April 12, 2016 (0000 UTC), on the right shows temperature anomalies at the top end of the scale (20°C or 36°F) over most of Greenland and Baffin Bay, while the Arctic as a whole is hit by a temperature anomaly of over 5°C (over 9°F), compared to 1979-2000.
Furthermore, ocean temperatures are currently very high. These high temperatures, together with the poor condition of the sea ice, make that chances are that the sea ice will be largely gone by September 2016.
 |
| [ click on images to enlarge them ] |
The image below shows that, on April 7, 2016, sea surface in the Barents Sea was as warm as 10.1°C or 50.2°F, an anomaly of 9.4°C or 16.9°F from 1981-2011 (at the location marked by the top right green circle), while there were anomalies as high as 11.3°C or 20.3°F off the coast of North America (green circle bottom left).
The white line shows the approximate path of the cold exit current, while the red line shows the approximate path of the warm entry current.
The high temperatures in the Barents Sea give an indication of the ocean heat traveling toward the Arctic Ocean, while the high temperature anomalies off the east coast of North America give an indication of the heat that is building up there. Much of this heat will make its way to the Arctic Ocean over the coming months
 |
| April 11, 2016: SST anomalies as high as 11.6°C or 20.8°F |
Sea ice acts as a buffer, absorbing heat and keeping the temperature of the water at freezing point. Without such a buffer, further heat will instead make that the temperature of the water will rise rapidly. Furthermore, less sea ice means that less sunlight gets reflected back into space and more sunlight instead gets absorbed by the Arctic Ocean.
These are just some of the many feedbacks that accelerate warming in the Arctic. Warm water reaching the seafloor of the Arctic Ocean can penetrate sediments that can contain huge amounts of methane in the form of hydrates and free gas, triggering abrupt release of methane in gigantic quantities, escalating into runaway warming, and subsequent destruction and extinction at massive scale.
On a 10-year timescale, the current global release of methane from all anthropogenic sources already exceeds all anthropogenic carbon dioxide emissions as agents of global warming; that is, methane emissions are more important than carbon dioxide emissions for driving the current rate of global warming.
Above image shows that growth in methane levels has been accelerating recently; a trendline points at a doubling of methane levels by the year 2040. Unlike carbon dioxide, methane's GWP does rise as more of it is released. Methane's lifetime can be extended to decades, in particular due to depletion of hydroxyl in the atmosphere.
The situation is dire and calls for comprehensive and effective action as described at the Climate Plan.
Albert Kallio comments:
More could have been added from the last National Snow and Ice Data Center (NSIDC) Arctic sea ice report for March, the general outlook for massive sea ice loss because the near-all-time record low marine snow and ice cover is coinciding with near-all-time record low terrestrial snow cover. NSIDC forecast that due to dark surfaces being so high, this easily leads to loss of sea ice. In fact, 2016 situation is even worse that it was previous record loss 2012 when snow cover was much larger. Same in 2007 when the sea ice area was slighly smaller, there was much larger terrestrial snow cover. Furthermore, neither 2007 nor 2012 occurred during strong El Nino like 1998. El Nino 2015-2016 is the strongest ever, also accompanied by the very warm Indian Ocean, Atlantic Ocean, and Southern Ocean around Antarctica. At times Antarctic sea water temperatures were also high leading to second smallest Austral summer sea ice at one point. Sea ice area also around Antarctica has been smaller than average most of time, despite increased melt water and reduced salinity - due to high temperatures. All these additional factors should be added into your conclusions without forgetting to mention that the added heat in the earth system is ripping the Polar Vortex apart as the jet streams have started to blend into other irregular atmospheric wind patters. Note also the increased flow of sea ice through the Fram Strait due to lowered spatial viscosity of sea ice that also results from larger wave action, vertical mixing of ocean by wind, thinner sea ice breaking easier apart and collapsing into pack ice, as well as being mostly seasonal ice (containing trace amounts of salts that make the chemical bounds in ice crystals weaker and fragile and melting easier), May be you can update and rejoice on NSIDC's March 2016 report noting all the points therein..
The situation is dire and calls for comprehensive and effective action as described at the Climate Plan.
Albert Kallio comments:
More could have been added from the last National Snow and Ice Data Center (NSIDC) Arctic sea ice report for March, the general outlook for massive sea ice loss because the near-all-time record low marine snow and ice cover is coinciding with near-all-time record low terrestrial snow cover. NSIDC forecast that due to dark surfaces being so high, this easily leads to loss of sea ice. In fact, 2016 situation is even worse that it was previous record loss 2012 when snow cover was much larger. Same in 2007 when the sea ice area was slighly smaller, there was much larger terrestrial snow cover. Furthermore, neither 2007 nor 2012 occurred during strong El Nino like 1998. El Nino 2015-2016 is the strongest ever, also accompanied by the very warm Indian Ocean, Atlantic Ocean, and Southern Ocean around Antarctica. At times Antarctic sea water temperatures were also high leading to second smallest Austral summer sea ice at one point. Sea ice area also around Antarctica has been smaller than average most of time, despite increased melt water and reduced salinity - due to high temperatures. All these additional factors should be added into your conclusions without forgetting to mention that the added heat in the earth system is ripping the Polar Vortex apart as the jet streams have started to blend into other irregular atmospheric wind patters. Note also the increased flow of sea ice through the Fram Strait due to lowered spatial viscosity of sea ice that also results from larger wave action, vertical mixing of ocean by wind, thinner sea ice breaking easier apart and collapsing into pack ice, as well as being mostly seasonal ice (containing trace amounts of salts that make the chemical bounds in ice crystals weaker and fragile and melting easier), May be you can update and rejoice on NSIDC's March 2016 report noting all the points therein..
On April 3rd, 2016, Arctic sea ice extent was at a record low for the time of the year, further confirming that the...
Posted by Sam Carana on Tuesday, April 5, 2016
Learning from the Kolkata Overpass Collapse
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On Thursday Mar. 31, around noon, the busy Rabindra Sarani-KK Tagore Street crossing in the city of Kolkata, India (population 4.5 million) was crowded with shoppers and people having lunch in open-air eateries. Crowds that a Westerner would consider to be a mob scene are routine in the Indian subcontinent, and the density of street-level shops makes many thoroughfares almost impassible by automobile. To alleviate this congestion, in 2008 the Hyderabad-based construction conglomerate IVRCL won a bid to construct an overpass that would carry vehicular traffic above the existing street. Construction began in 2009 and was due for completion in 2012. But the firm ran into financial and land-acquisition difficulties, with consequent project delays, and so last week one of the last parts of the projected 2+ kilometer-long overpass was still under construction above the street.
By Wednesday, Mar. 30, a long straight section of the overpass was complete, and concrete was poured that night for a section next to a turn at the crossing, where steel girders already were suspended above the road. At about 12:25 PM Thursday, some 300 feet (100 meters) of the overpass collapsed onto the street below. As of Apr. 2, the death toll stood at 27, but more were missing and over 100 people were injured.
While the cause of the collapse is under investigation, the IVRCL firm has been charged with culpable homicide and three members of the firm have been arrested. This is after one firm representative termed the collapse "an act of God."
The construction phase of any large civil-engineering project is fraught with hazards that only good planning and expert supervision at all times can avoid. As a civil-engineering professor interviewed about the tragedy pointed out, right after a poured-concrete structure is set in place, the weight of the newly poured material must be supported by temporary scaffolding before the concrete sets. In contrast to the finished product, which office-based engineers can design at their leisure to withstand known stresses, temporary scaffolding is erected onsite in an ad-hoc way, and may have hidden defects that would require more engineering knowledge to avoid than the onsite construction workers and supervisors have. It was apparently one such defect that led to the disaster in Kolkata last week.
From videos shot during the collapse, it appears that few if any pedestrian or vehicle barriers were in place to keep people away from the construction site. Admittedly, this would have been difficult, like temporarily shutting down Times Square in New York City for construction. And businesses on the street undoubtedly would have complained if large sections of the surface street had been blocked off, impairing access to some shops. But events have proved that the tradeoff would have been worth it, if excluding traffic from under the most hazardous parts of the overpass during construction would have saved lives.
While some commenters on Indian news sites complained that such things are never allowed to happen in the so-called First World, only a year ago I reported in this space about a similar but smaller-scale accident involving overpass construction, right here in Texas. While a prefabricated-concrete-beam overpass was being built over the busy I-35 freeway near Salado, Texas, a truck carrying an overheight load struck one of the beams before it had been firmly fixed in place. It shifted and knocked down several other beams, one of which killed the driver of a pickup truck. Again, this accident could have been prevented by diverting traffic from underneath the overpass, but the result would have been permanent miles-long backups on I-35 that might have provoked angry citizens to mount a protest march at the Texas Department of Transportation.
Any complex engineering project is a series of compromises with safety, expenses, schedules, personnel, and other resources all in the mix. In the West, a relative abundance of resources has led engineering organizations to err on the side of more money traded for more safety. In India, as the comparatively poor track record of fatal building and construction collapses attests, getting the project done cheaply sometimes takes priority over getting it done safely. India is a democracy, and it may be that the current level of construction safety reflects an increased urgency to solve the nation's civil-engineering needs faster and with fewer resources than Western-style engineering would allow. It is bad enough when a privately-owned building collapses. But a public-works project such as an overpass inherently affects more people, and carries more potential for harm. This is why most public-works project specifications require licensed professional engineers to supervise the design phase. But the best designers in the world will be unable to prevent onsite accidents if the people who actually do the construction are not capable of understanding the hazards and engineering challenges involved.
At least three members of the IVCRF firm have been arrested in connection with the tragedy and charged with culpable homicide. The degree to which they are responsible is now going to be determined by the legal process, which may take months or years. Regardless of the fate of the engineers and managers involved in this accident, to prevent future tragedies like this a sea change will have to take place in the entire construction industry in India.
I have mentioned before a simple safety code that was once emblazoned on bronze plaques in Bell System telephone exchanges throughout the U. S.: "No job is so important and no service is so urgent—that we cannot take time to perform our work safely." That was back when the Bell System was a monolithic nation-like organization, and it could afford hundreds of bronze safety plaques. But everyone working in a business that creates potential hazards for its own employees, and especially for innocent bystanders, can afford to make the Bell System safety creed their own. And something like this could go a long way toward making Indian construction sites and buildings safer places to be.
Sources: I referred to reports on the Kolkata overpass collapse carried on the National Public Radio website at http://www.npr.org/sections/thetwo-way/2016/04/02/472797620/after-overpass-collapse-in-kolkata-firm-charged-with-culpable-homicide, ABC News at http://www.abc.net.au/news/2016-04-02/indian-authorities-arrest-three-more-over-bridge-collapse/7294848,
the Times of India at http://timesofindia.indiatimes.com/city/kolkata/Kolkata-flyover-collapse-Its-an-act-of-god-says-builder/articleshow/51634766.cms, The Week at http://www.theweek.in/news/india/what-caused-kolkata-flyover-collapse-experts-speak.html, and The Wire at http://thewire.in/2016/03/31/photo-gallery-after-the-kolkata-flyover-collapse-26961/and http://thewire.in/2016/04/01/kolkata-flyover-collapse-18-dead-over-60-injured-26907/. My blog article http://engineeringethicsblog.blogspot.com/2015/03/a-bridge-too-close.html,
"A Bridge Too Close," about the I-35 accident appeared on Mar. 29, 2015.
iPhone SE Features Sony and Omnivision Sensors
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Chipworks reverse engineering reveals that Apple iPhone SE FaceTime front-facing camera uses Omnivision 1.2MP sensor with pixel pitch of 1.75 µm. The die, which features OV2E0BNN die markings, has a size of 4.3 mm x 4.1 mm (17.6 mm2):
The rear camera contains a Sony stacked (Exmor RS) sensor with a 6.02 mm x 4.83 mm (29.1 mm2) die size. The pixel pitch is 1.22 µm, as was used for the iPhone 6s/6s Plus. The decapsulated die photos from the SE and 6s Plus rear image sensors appear to be the same chip:
The rear camera contains a Sony stacked (Exmor RS) sensor with a 6.02 mm x 4.83 mm (29.1 mm2) die size. The pixel pitch is 1.22 µm, as was used for the iPhone 6s/6s Plus. The decapsulated die photos from the SE and 6s Plus rear image sensors appear to be the same chip:
