A new instrument for investigating Cherenkov-Vavilov radiation on the basis of a camera Obscura, called for short the Cherenkov differential detector (CDD), was introduced at the Yakutsk Extensive Air Shower Array in 2003.
The Cherenkov differential detectors are located around the center of the current Yakutsk EAS array. This location allows the detectors to operate as part of the larger array and use its data: trigger signal, shower arrival angles, axis coordinates in the installation plane, etc. The CDD photomosaic consists of a photomultiplier array, each of the photomultipliers observing a certain height of the celestial sphere through a narrow slit of the camera. An important advantage of CDD is the ability to determine the spatio-temporal pattern of the development of the Cherenkov component of the EAS in the atmosphere.