The Inertial Navigation System (INS) is based on dead reckoning by a double integration of aircraft accelerations that are measured by the accelerometers located on a gyro-stabilized platform. The fundamental property of the INS is the accumulation of coordinate measurement errors over time (platform alignment errors and accelerometer errors are also integrated twice). With the use of INS mathematical models, we have achieved a realistic error accumulation effect, as well as a physical alignment of the gyro-stabilized platform when the helicopter is started.
As a result, the INS-derived location can only be determined with limited accuracy. The error in the calculation of coordinates accumulates at the rate of several kilometers per hour and when starting the INS, it will be necessary that the helicopter remains stationary throughout the alignment procedure. Otherwise, a less accurate alignment will lead to an accelerated accumulation of errors. Three different alignment options will be available: “fast” allows you to take off rapidly but it provides low-accuracy during the flight; “normal” and “precise” provide better accuracy with greater alignment times.
When using INS for long flights, correction/fix taking points will be available. Prominent reference points on the ground with known coordinates make it possible to eliminate accumulated errors in two ways: by flying over the landmark, or by using “Shkval” tracking of the reference point located away from the route. Thus, navigation in Ka-50 will become more realistic with the simulation of INS errors that are present in real life.