tb_range_doppler_map — 2D typed op

Data kinds: beatcubeimage

Call: fullseye.apply(img, "tb_range_doppler_map", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

Usage

The 2-D FFT of a beat cube -> a `(n_doppler, n_range)` magnitude map.

Fast time transforms to range (last axis, not shifted: bin `j` is

`j * c*f_s/(2*S*N_s)` metres, and a physical range is always positive so

the whole `[0, f_s)` band is used). Slow time transforms to velocity

(middle axis, `fftshift`ed so the map is centred on zero velocity: bin

`i is (i - N_c//2) * lambda/(2*N_c*T_c)` metres per second, positive =

receding).

The antenna axis is collapsed by *combine*: `"incoherent"` (default) is the

mean of the magnitudes, which is angle independent and therefore the

right default for detection; `"coherent"` is the magnitude of the mean,

i.e. a beam pointed at boresight, which attenuates an off-boresight target on

purpose. `antenna=k uses element k` alone. For a single-element cube

all three agree exactly.

`normalize=True divides by N_c * N_s`, so a bin-centred target of

amplitude `a peaks at exactly a` (measured: 1.0 for a unit target,

absolute error 0.0). The default `False` keeps the raw FFT magnitude.

No window is applied — compose :func:fmcw_window_apply first if you want

one. The output is a plain 2-D float64 array, so every 2-D operator in

Fullseye (threshold, morphology, labelling, blob measurement — the pieces a

CFAR detector is made of) applies to it directly.

Raises `ValueError`: a real-valued cube (it would put a mirror ghost of

every target at a fabricated range), fewer than 2 chirps or 2 samples, an

out-of-range *antenna* index, an unknown *combine*, a cube over the element

cap, an FFT that overflows to NaN, or NaN/Inf on the way in.

Typed bridge of the rangedoppler op `range_doppler_map into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. This op has no tunable parameter; a and b` are unused.

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

Runnable examples (verified samples that actually call this op)

• (none yet)

Ops the type connects to (they accept image as input)

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

Same category (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 operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

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