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A dead zone network drives the velocity motor in steps which are smoothed to provide the integrated acceleration (= velocity) signal. The velocity integrators operate in a similar manner to the acceleration integrators, except that the output signal is not smoothed because the so-called M-transmitters are step-function devices.
The blind velocity for a specific pulse repetition frequency (PRF) is an integer multiple of the following, which causes the signal to have zero doppler. B l i n d V e l o c i t y = ( C × P R F 2 × T r a n s m i t F r e q u e n c y ) {\displaystyle Blind\ Velocity=\left({\frac {C\times PRF}{2\times Transmit\ Frequency}}\right)}
Doppler systems involve velocity measurements similar to the kind of measurements made using a strobe light. For example, a strobe light can be used as a tachometer to measure rotational velocity for rotating machinery. Strobe light measurements can be inaccurate because the light may be flashing 2 or 3 times faster than shaft rotation speed.
By storing the phase signal, instead of the original analog signal, or video, and comparing the stored and current signal for changes in phase, the moving targets are revealed. This technique is far more resistant to noise, and can easily be tuned to select different velocity thresholds to filter out different types of motion. [1]
The unambiguous velocity of an L-Band radar using a PRF of 10 kHz would be 1,500 m/s (3,300 mile/hour) (10,000 x C / (2 x 10^9)). True velocity can be found for objects moving under 45,000 m/s if the band pass filter admits the signal (1,500/0.033). Medium PRF has unique radar scalloping issues that require redundant detection schemes.
A pilot uses the VDA, and ground speed, to compute a rate of descent (from a table found in the U.S. Terminal Procedures Publication), which is flown using the Vertical velocity indicator. [1]: 4–22, 4–23 Aircraft approved for LNAV/VNAV minimums include the Boeing 737NG, 767, 777, the Airbus A300 and some ATRs. [1]: 4–26 [2]
The airspeed indicator (ASI) or airspeed gauge is a flight instrument indicating the airspeed of an aircraft in kilometres per hour (km/h), knots (kn or kt), miles per hour (MPH) and/or metres per second (m/s). The recommendation by ICAO is to use km/h, however knots (kt) is currently the most used unit.
When a launch is commanded, a complete retesting of the G&C system is made prior to entering the flight program. During flight, the computer uses missile attitude, change of attitude rate, and velocity signal inputs to solve a series of guidance, steering, and control equations.