China is building 119 intercontinental ballistic missile silos in a desert in the northwestern section of the nation, according to photos collected by commercial satellites and examined by arms control experts early this year.
That discovery attracted the interest of imaging analyst James Lewis, who works as a solution engineer lead at the L3Harris firm, who wanted to delve deeper after reading about it in a Washington Post piece on June 30. Lewis found that the Chinese are also building a big wind turbine farm, probably to fuel the missile silos, plus roads to link the silos with the power plants, using a commercial imagery processing tool and open-source radar imagery from the commercial satellites.
Lewis claimed he acquired the knowledge utilizing radar imagery from the Sentinel-1, which is a European Space Agency (ESA) constellation of 2 polar-orbiting satellites that conduct C-band SAR (synthetic aperture radar) imaging, which sees beyond bad weather and clouds, during a presentation on October 7 at the 2021 GEOINT Symposium.
Lewis did change detection analysis with the help of an L3Harris device called ENVI SARscape. He looked at SAR imagery from a year before the silo pictures got published, and investigated that area for the full year to determine if any changes had occurred. Unlike optical images, SAR sensors create a picture by constantly illuminating the ground instead of relying on sunlight. SAR imagery does not resemble an optical image, which the human eye is better familiar with.
According to Lewis, the SAR images of the desert where missile silos were discovered revealed the presence of man-made things. According to him, a Google Earth search showed that they were wind turbines. “There isn’t much of a population there.” So, why are all such wind farms being built there?… They’re clearly attempting to power a very huge object.”
“We could see the shift over time,” Lewis said, referring to a year’s worth of images. “You can progressively start noticing dark lines, and are all the interconnecting roads between silos and also where they were constructing out those wind turbines.”
“You can see they’ve been really busy bees from July 2020 to July 2021,” he remarked. Lewis said he’s quite convinced there were more than 119 missile silos installed during that year, but he wouldn’t tell how many. While SAR imaging can help detect operations, it is not a replacement for optical photos like the ones which led to the identification of the Chinese silos, according to Lewis. “What we wanted to investigate was how much more movement we could tell using SAR,” he explained.