The highest pixel photo ever born! How are 3.2 billion pixel digital photos taken?

In the U.S. Department of energy’s Stanford linac National Accelerator Laboratory, staff aimed an array of imaging sensors at a Roman cauliflower and took this black-and-white picture. This seemingly commonplace picture is not only an improvement in imaging capabilities, but also an important milestone in astronomy. < / P > < p > the reason why this photo is so special is that it is the first time that SLAC staff have taken a digital photo of 3.2 billion pixels, and it is also the highest pixel photo obtained by a single imaging. The size of these photos requires 378 4K UHD TV screens to fully display one of them; they are so clear that you can see a golf ball about 24 kilometers away. The imaging sensor array that took this image will be the core component of the Willa Cooper Rubin Observatory camera. The observatory in Chile is named after Willa Rubin, an astrophysicist who died four years ago, to commemorate her important contribution to the field of dark matter research. < / P > < p > next, the sensor array will be incorporated into the world’s largest digital camera still under construction by SLAC. After the Rubin Observatory is set up, the camera will be able to take a panoramic view of the entire southern sky – every few nights; and so on, for ten years. Every night, the Rubin Observatory processes and stores more than 20 terabytes of data. < / P > < p > these data will be transferred from the camera to the Rubin Observatory’s spatiotemporal heritage survey project database, which contains more galaxies than the earth’s population and the motion information of countless celestial bodies. Using the LSST camera, the Rubin Observatory is able to make the largest astronomical film ever made and uncover many important mysteries of the universe. Among them are the mysteries of dark matter and dark energy: the data produced by LSST will be used in the dark energy science collaboration project to help us further understand the mysterious energy that accelerates the expansion of the universe. < / P > < p > “this is an important milestone for us,” said Vincent riott, director of the LSST camera program and at Lawrence Livermore National Laboratory of the U.S. Department of energy. “The focal plane is the right and sensitive eye of Rubin observatory to provide images for LSST.” < / P > < p > Steven Kahn, director of Rubin Observatory and from SLAC, said: “this is one of the most important achievements of the entire Rubin Observatory project. The construction and successful test of focal plane of LSST camera is a great success for the camera team. This success will enable the Rubin observatory to open up the next generation of astronomical research. ” < / P > < p > in a sense, the focal plane is like an imaging sensor in a consumer digital camera: it captures the light emitted or reflected by an object and converts it into an electrical signal to generate an image. But the focal plane of the LSST camera is much more complicated. In fact, it contains 189 independent sensors, also known as charge coupled devices. Each CCD can output 16 million pixels – about the same amount as most modern digital camera imaging sensors do. < p > < p > the focal plane diameter of the LSST camera is at least 61 cm, including 189 independent sensors, and can output 3.2 billion pixel images. < / P > < p > the installation of the so-called “scientific Raft” was completed at the Brookhaven National Laboratory of the U.S. Department of energy: a “scientific Raft” contains nine CCD devices and their auxiliary components. After installation, the “scientific Raft” is transported to SLAC. At SLAC, the camera team inserts 21 “science rafts” and four special rafts that are not used for imaging into a fixed grid. < / P > < p > the single imaging sensor and auxiliary components of the focal plane of the LSST camera are packaged into units called “rafts”. There are two different units: 21 square rafts, each containing nine sensors, output images for the Rubin Observatory science project; in addition, there are four special rafts, each containing three sensors, for camera focusing and for synchronizing the telescope with the earth’s rotation. < / P > < p > focal plane has many special properties. It not only contains 3.2 billion pixels, but also these pixels are very small. The whole focal plane is very flat, and the bump is no more than one tenth of the width of human hair. This ensures that the camera can output clear and high resolution images. The diameter of the focal plane is about 61 cm, which can only be described as “huge” compared with a full frame consumer camera of about 3.5 cm. With such a large focal plane, the sky is about 40 full moons in size. What’s more, the design of the telescope is so sensitive that it can detect objects 100 million times darker than visible to the naked eye – like seeing a burning candle thousands of kilometers away. < / P > < p > “these parameters are horrendously large,” says Steven Leeds, a LSST camera project scientist at the University of California, Santa Cruz. “These unique properties will drive the Rubin Observatory’s ambitious scientific research.” < / P > < p > over the next 10 years, the camera will collect images of about 20 billion galaxies. “These data can help us understand the evolution of galaxies, and test our dark matter and dark energy models more deeply and accurately,” Leeds said. “Whether it’s for detailed studies of the solar system, or for objects on the edge of the observable universe – this Observatory will be an excellent facility for many scientific fields.” A large focal area of < 40 months is enough for the camera to capture the full focal plane of LSP >. Its resolution is so high that you can see a golf ball from about 24 kilometers away. The focal plane was assembled earlier this year. Over the course of six months, the SLAC crew nervously inserted 25 science rafts into narrow slots in the grid. In order to maximize the imaging area, the gap between sensors on the adjacent raft is less than 5 hairs wide. The imaging sensors are easy to crack when they contact each other, so the whole operation process is very difficult. Hannah polek, SLAC Mechanical Engineer in charge of sensor integration, said: “this project is not only high-risk, but also has strict tolerance, which is very challenging. But with such an all-round team, we can say that we have accomplished quite well The focal plane has been placed inside the cryostat, where the sensors are cooled to – 101 ℃, which is the temperature required for their normal operation. Because of the epidemic, members of the camera team were unable to enter the laboratory for months. They eventually returned to limited work in May and were required to follow strict social distance requirements. At present, they are conducting large-scale tests to ensure that the focal plane can meet the technical requirements of the Rubin Observatory science project. < / P > < p > one of the tests was the first 3.2 billion pixel image of various objects, including Roman cauliflower. To do this before the camera has been assembled, the SLAC team used 150 micron pinholes to project images onto the focal plane. < / P > < p > in the next few months, they will insert a cryostat and focal plane into the camera body and add camera lenses, including the world’s largest optical lens, shutter and filter replacement system for studying different color night sky. By mid-2021, the camera, the size of an SUV, will be ready for final testing, which will then be shipped to Chile. Joanne Hewitt, chief research officer and deputy director of the basic physics laboratory at SLAC, said: “it’s very exciting that the camera is just around the corner. We are proud to have played such an important role in this crucial part of the establishment of the Rubin observatory. It’s a milestone, and it’s a big step towards exploring the fundamental problems of the universe in an unprecedented way. ” ASMC, a lithography maker, was one of TSMC’s 14 top suppliers last year