A Model for the Effect of Time Delay Errors on the Polar Response of a Linear Array of Sensors.
Abstract
In conventional time domain beamforming the receiver outputs are delayed such that the outputs due to a signal arriving from a selected direction are added in phase. If the receiver outputs are sampled time series then all time delays must be integer multiples of the sampling interval. In general the required delays are not exact multiples of the sampling interval and an appropriate choice for the approximating delays is to choose the nearest integer multiple of the sampling interval. This approximation of the required time delays modifies the polar response of the array. In this paper a model describing the degradation in the polar response of a linear array of equispaced sensors at selected angles due to the time delay errors is proposed. At these angles the perturbed polar response is characterized by a number of isolated high sidelobes. These are teamed quantization lobes and their position and approximate height are described by the model. Unfortunately the model is limited by its sensitivity to small perturbations in the steered direction. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1978
- Accession Number
- ADA082117
Entities
People
- D. A. Gray