The satellite-aided M4000 (abbreviated as "M4000") is a fiber-optic strapdown inertial measurement unit. This M4000 can operate in two modes: integrated navigation (GPS integration, log integration) and undamped mode, outputting information such as attitude, position, velocity, and heave. ⚪  Scope of application: Marine surveying and mapping; Surface and underwater warships; ⚪  External sensors compatible with the product: GPS (single-ended or differential), with options for built-in GPS board or external GPS information input; DVL Doppler sensor.