HTC and Samsung both include the standard array of environmental sensors, including accelerometer, proximity, ambient light and gyroscopic movement. Both also include one for reading barometric pressure. In addition, both have GPS, GLONASS and digital compass location capabilities. Samsung also has an additional sensor for navigating via Beidou, the Chinese GPS system, plus sensors for humidity sensor and heart rate. Galaxy devices also include gesture sensors that track eye movement, and can control apps and magnify the screen without touching it.