BL-904 (Type 704) Chinese Artillery Location and Fire Correction Radar

The BL-904 (Type 704) Chinese Artillery Location and Fire Correction Radar is an X-band (NATO I-/J-band) (8–12 GHz) 3D artillery locating and fire correction radar for installation in a truck-mounted configuration. The BL-904 was developed by the Xi'an Electronics Engineering Research Institute, founded in 1967, also known as Institute No 206 of China Arms Industry Group Corporation. It was initially named Type 704, followed by an improved performance version called Type 704M. The system is similar to the United States' AN/TPQ-36 in both appearance and performance (as claimed by the manufacturer). The system can also be used to track friendly artillery fire. It calculates the impact error of friendly artillery rounds and provides automatic correction parameters for increased accuracy. The X-band BL-904 artillery locating and fire correction radar is carried on two trucks, one with the radar, and the other possibly providing the C2 facility. The command cabin contains the operation and control panel, data processing equipment, computer monitors/displays, and so on. The radar has a claimed establishment time of less than 10 minutes, a removal time of under five minutes, and a claimed reaction time of approximately five seconds. It has an autonomous positioning and orienting system using GPS, and the communications facilities include radio and line. The system is manned by a four-man crew. The latest version reportedly utilises the more advanced lens arrangement for its planar passive phased-array antenna, instead of the simple horn arrangements used in the earlier versions. The BL-904 is no longer in production, and has been replaced by the RA3 artillery locating and fire correction radar (also known as the BL904A) by the contractor. However, the system remains in service with the existing users.