Estimation of Range and Bearing Angle -

1. Bearing-angle estimation

A passive detection system consists of two acoustic receivers. The separation between the receivers is 2.5 meters. The acoustic propagation speed in air is 343.6 m/s. The acoustic data tracks detected by the receivers are given. The sampling rate of the A/D conversion is 48 MHz. Estimate the bearing angle of the acoustic source.

2. Range estimation

The purpose of this exercise is to perform step-frequency radar imaging using FFT for range estimation.

The data set was taken over a section of the walkway pavement in front of the Broida Hall. The ground-penetrating radar imaging unit scanned along a linear path and took data at 200 spatial positions. The spatial spacing between the data-collection positions is 0.0213 m (2.13 cm).

At each data-collection position, the system illuminates the subsurface region of the walkway area with microwaves in the step-frequency mode, stepping through 128 frequencies with a constant increment, from 0.976 GHz to 2.00 GHz. The relative permittivity εr is approximately 6.0.

The data set is in the form of a (200 x 128) array, corresponding to 128 complex-amplitude values (for the 128 frequencies) at 200 receiving positions.

Your assignment is to perform the image reconstruction of the subsurface profile. Your result should be a two-dimensional image plot (magnitude-only).

Please note:

(a) The propagation speed needs to be adjusted by the relative permittivity.

(b) The depth profile needs to be scaled by a factor of two for the round-trip propagation.

(c) The spatial scale of your image profile should be approximately the same, in both directions for effective visualization.

Your report should include (a) a detailed description of your approach and signal processing procedures, (b) resultant image, (c) code, and (d) a summary.