Since noise voltages are spread more or less uniformly across an extremely wide frequency band, less of the noise is amplified by a receiver that is designed for a wide pulse than for a narrow one.
The band is narrower the wider the pulse is made. To reproduce a pulse, the receiver must amplify not simply a single frequency but a whole band of frequencies. The effect of increasing the pulse duration is made greater if the receiver is modified to accommodate the longer pulse duration. For this reason, many new radars are being designed so that they may send out long pulses when long-range detection is desired. It is apparent, however, that greater range can be obtained with a long pulse than with a short one.
#RANGE RESOLUTION CALCULATOR FULL#
The full effect of pulse duration on maximum range is not thoroughly understood. However, it must be remembered that doubling the peak power of a set does not double the maximum range obtainable on a particular target it increases the range only 20 per cent. If the peak power transmitted by a radar is great, the power available for reflection back to the radar at any target that the pulse can reach will be greater than if a low-power pulse is sent out. Among these are the skill and experience of the operator, the size, composition, and altitude of the target, the effect of reflection from the water, and the condition of the weather. Other factors external to the set at times exert a strong influence on the performance of the set.
Thus, the peak power transmitted by the radar, the duration of the transmitted pulse, the pulse repetition rate used, the efficiency of the lines that carry the pulse to the antenna, the height of the antenna above the water, the width of the lobe radiated from the antenna, the sensitivity of the radar receiver, and the type of indicator used in the set are a few of the most obvious characteristics of the equipment that affect range performance. The maximum range at which targets can be detected by radar is affected not only by many characteristics of the equipment itself, but also by the operator and several other factors external to the set.
Matériel factors: Training of maintenance personnel preventive maintenance: reliability of equipment performance reports echo box. Determination of altitude by radar: Altitude accuracy resolution in altitude reliability of altitude determination.ĭ. Determination of bearing by radar: Bearing accuracy: bearing resolution reliability of radar bearings.Ĭ. Determination of range by radar: Maximum range minimum range range accuracy range resolution reliability of radar ranges.ī. HyperWar: The Capabilities and Limitations of Shipborne Radar C HAPTER VĪ.
0 kommentar(er)
