China made 0.06 High Accuracy FOG north finder

1.1 Product Usage

Fiber optic gyroscope (FOG) north finder is mainly used to determine the true north direction rapidly and independently. It uses the two basic characteristics of gyroscope, i.e. precession and axis-fixing, to realize the autonomous North finder. The angular rate of the earth's rotation is obtained by high precision FOG tracking. The angular rate signal of the earth's rotation is calculated, and the angle between the main axis of the gyro and the true north direction of the earth is calculated to provide azimuth information for the carrier.

1.4 Key features
a) North finding time:≤3min;
b) North finding accuracy(1σ):≤0.06°(FNF701) ;≤0.1°(FNF702); ≤0.5°(FNF703)
c) Horizontal accuracy:≤0.1°
d) Weight:≤4.5kg
e) Power supply :24±4V;
f) Power consumption:25W(Peak value);
g) Interface:RS422;
h) Power-on preparation time 6 minutes;
i) Working mode: Self-check is started after power-up, and after self-check is completed, it is controlled by the upper computer to find the north. After the north-search is completed, the result of north-search is sent to the upper computer.

1.5 Environmental Requirements
1) Working temperature:-40℃~+65℃;
2) Storage temperature:-45℃~+70℃.
3)Sand and Dust: Under the condition of sand and dust stipulated in 2 conditions of GJB150.12, the gyro north finder shall not appear the following situations:
a. Institutions are too tight, stuck or malfunctioning;
b. Short circuit or abnormal operation of electrical components;
c. Dust in internal optical and mechanical parts.

4)Salt fog

The gyro north finder should meet the salt fog condition of GJB150.11.
5)Hot and humid environment Conditions
Relative humidity: 95%; temperature: 30±2C; storage time 72 hours.
Insulation resistance should be no less than 2 MΩ_, metal surface should not be rusted, coating should not appear foaming, spalling and other phenomena, and can work normally.
6)vibration environment
Sinusoidal Scanning Vibration Environment Requirements
Frequency range: 5Hz ~ 5.5Hz, vibration displacement (dual amplitude) 25.4mm
Frequency range :5.5Hz~200Hz,vibration acceleration 1.5g;
Scan time :12min;
Vibration direction:3 axises (X axis ,Y axis, Z axis );
Each axis:2h;
7)Impact Environmental Conditions
Shock Waveform: Semi-sinusoidal Pulse
Peak acceleration: 20g, pulse width 11ms,
Shocks times per axis (X axis , Y axis , Z axis ) is 3.
8)Collision Environment Conditions
Peak acceleration: 10g
Pulse width: 16ms
Collision Rate: Vertical Axis 80 times/min
Collisions times: 1000±10
Collision Direction: Vertical Installation Plane