tb_beamform_delay_sum — 2D typed op

데이터 종류: beatcubesignal

호출: fullseye.apply(img, "tb_beamform_delay_sum", a=0.5, b=0.5)(2-D 는 이미지 1 장 + 스칼라 노브 2 개 a,b∈[0,1] 모델)

사용법

하나의 range-Doppler 셀에 대한 지연-합(delay-and-sum, Bartlett) 각도 스펙트럼.

> 아래 상세 설명은 원문입니다 —— 요약과 제목은 번역되어 있습니다.

Takes the per-antenna complex value at a single range-Doppler cell — by

default the strongest one — and for each steering angle removes the expected

inter-element phase and sums:

`P(theta) = |sum_k conj(exp(1j*2*pi*d*k*sin(theta)/lambda)) * x_k|^2`

which peaks at the true arrival angle with value `(N_a * |a|)^2`: the

aperture gives `N_a in amplitude, N_a^2` in power. That is the exact

ground truth the tests pin. Measured with 8 elements: the peak power is

bit-exactly `(N_a*N_c*N_s)^2 = 268435456` (relative error 0.0), and

sweeping the true angle from -80 to +80 degrees in 5-degree steps (33 cases)

the reported angle matches the truth with a maximum error of 0.0 degrees.

The steering grid defaults to `arange(-90, 90.5, 1.0). normalize=True`

divides by `N_a^2 * N_c^2 * N_s^2` so that a unit-amplitude bin-centred

target peaks at 1.0.

Returns a 1-D float64 array of powers, one per grid angle — a plain signal,

so :mod:dsp's `find_peaks and :mod:funct1d`'s smoothing apply to it.

Use :func:beamform_doa if you want the angles themselves.

*range_bin* is a plain `0..N_s-1` index; *doppler_bin* is the signed

velocity bin, the same convention :func:range_doppler_peaks reports, so a

detection can be handed straight back in. Both or neither — half a cell

address raises rather than quietly beamforming the strongest cell instead.

Raises `ValueError`: no aperture — either a single element, or many

elements packed into under ~0.28 wavelengths. In both cases the spectrum is

flat to within float noise and `argmax` returns the first grid angle, i.e.

a confident report of -90 degrees that is pure tie-breaking (measured: 8

elements at 1e-12 m spacing gave a peak-to-trough spread of exactly 0.0 and

reported -90.0). Also: an all-zero cube or an all-zero selected cell; only

one of *range_bin* / *doppler_bin*; an out-of-bounds bin index; an angle grid

outside `[-90, 90]`; an FFT that overflows to NaN; plus the usual cube and

scalar refusals.

Typed bridge of the rangedoppler op `beamform_delay_sum into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. a drives wavelength_m (default 0.0038934); b` is unused.

참고(샘플 데이터·문헌)

• 샘플 데이터 카탈로그(DL URL / 라이선스) —— 2-D 는 skimage.data(BSD/public)+ 합성, 3-D 는 실데이터 소스(Stanford/PDS 등)의 DL URL.

• 연산자의 내력·참고문헌 —— 이 연산자 족의 바탕이 된 연구/기법의 출처.

실행 가능한 예제(이 연산자를 실제로 호출하는 검증된 샘플)

• (아직 없음)

타입이 이어지는 다음 연산자(signal 를 입력으로 받는 것)

identity · tb_create_funct_1d_array · tb_smooth_funct_1d_gauss · tb_smooth_funct_1d_mean · tb_derivate_funct_1d · tb_integrate_funct_1d · tb_zero_crossings_funct_1d · tb_abs_funct_1d

같은 카테고리(typed)

tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_angle_3points · tb_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal


*Provenance: ops.py — 2D 연산자 레지스트리. 이 op 노트는 tools/opdocs.py md 가 자동 생성합니다(직접 편집하지 마세요).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.