tb_beamform_delay_sum — 2D typed op

データ種: beatcubesignal

呼び出し: fullseye.apply(img, "tb_beamform_delay_sum", a=0.5, b=0.5) (2-D は 1 画像 + 2 スカラつまみ a,b∈[0,1] のモデル)

tb_beamform_delay_sum: input → output

*図は合成の入力 128×128 で実際に走らせた出力。左が入力、右が出力。点群は上から見た散布(明るさ = z)、1-D 列は折れ線、体積は z 方向の最大値投影、動画は中央フレーム、複素画像は振幅、絵にならない返り値は値そのもの。*

つまみ a を振る(0.1 / 0.5 / 0.9、もう一方は既定):

tb_beamform_delay_sum: knob a sweep (docs site)

*つまみ b は出力を変えない(実測: 0.1 / 0.5 / 0.9 で同一)。*

段階(前置きの op → この op。左から順):

tb_beamform_delay_sum: stages (docs site)

別の画像でも(合成シーン / 写真 / 硬貨。上段が入力、下段がその出力。つまみは既定):

tb_beamform_delay_sum: other inputs (docs site)

使い方

1つのレンジ・ドップラーセルに対する、遅延加算(delay-and-sum、Bartlett法)角度スペクトル。

> 以下の詳細説明は原文のままです —— 要約と見出しは訳出済み。

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.

参考(サンプルデータ・文献)

• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。

• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。

Studio で試す

下のプログラムは実際に走ることを確かめてある(図と同じ入力)。Studio のヘルプではこのブロックがボタンになり、その場で読み込んで実行できる。

img_to_beatcube 0.50 0.50
tb_beamform_delay_sum 0.50 0.50

▸ Load this pipeline  ·  Load & run

実行できる例(この op を実際に呼ぶ検証済みサンプル)

次の例は元の台帳 op beamform_delay_sum を呼ぶもの。この橋渡し op は同じ実装を fn(v, a, b) 規約に合わせただけなので、挙動はそのまま当てはまる(呼び出し形だけ違う)。

fmcw_range_dopplerpy -3.11 examples/fmcw_range_doppler.py

poc_multibeam_bathymetrypy -3.11 examples/poc_multibeam_bathymetry.py

型が繋がる次の op(signal を入力に取れる)

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

同カテゴリ(typed)

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


*Provenance: ops.py — 2D operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*

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