Range ambiguity in synthetic aperture radar (SAR) occurs when the distance to a target or feature in the radar scene exceeds the range resolution capability of the SAR system. SAR systems use the delay time of radar pulses to measure the distance to objects on the ground. If this distance is greater than half the radar pulse repetition interval (PRI), ambiguity arises because the system cannot distinguish whether the received signal is the actual range or a multiple of that. -this.
Range ambiguity in SAR can lead to errors in image formation and target localization if not properly handled via PRI selection or other techniques.
In ultrasound imaging, range ambiguity refers to a situation where the ultrasound system cannot accurately determine the distance to an object or tissue structure due to insufficient temporal resolution. Ultrasound systems emit pulses and measure the time it takes for the echoes to return from the tissues inside the body.
If the ultrasound pulse repetition frequency (PRF) is too high or the pulse duration is too long relative to the distance of interest, echoes from deeper structures may arrive before the system has completed treatment earlier echoes, leading to ambiguity in range measurement.
Continuous wave (CW) radar can overcome range ambiguity using techniques such as frequency modulation or varying the phase of the transmitted signal. These methods allow the CW radar to encode range information into the frequency or phase of the transmitted signal.
By analyzing the frequency or phase shift of the received signal, the CW radar can accurately determine the range to a target without being limited by the PRI as in pulse radar systems. This approach is particularly useful for measuring distances to targets that exceed the range resolution of pulse radar systems.
Radar ambiguities refer to uncertainties or errors in the interpretation of radar signals that can arise from various factors such as range, speed and angle measurements.
Range ambiguities occur when radar systems cannot accurately determine the distance to a target due to limitations in pulse repetition frequency (PRF), pulse duration, or processing capabilities. Velocity ambiguities arise when radar systems cannot distinguish the different speeds of moving targets within their measurement capabilities. Angle ambiguities occur when radar systems cannot accurately determine the direction or angle from which a signal is arriving, usually due to antenna resolution or beamwidth limitations.
Ambiguity management and mitigation are crucial in radar systems to ensure accurate target detection, tracking and situational awareness