process op• 資料種類:beatcube → beatcube
• 呼叫:import rangedoppler; rangedoppler.fmcw_window_apply(cube, window='hann', axis='range')(或 opsrangedoppler.get("fmcw_window_apply"))
沿拍頻立方體的距離軸和/或都卜勒軸施加週期窗。
> 以下的詳細說明為原文 —— 摘要與標題已翻譯。
The sidelobes of a rectangular (unwindowed) transform are -13.3 dB, so a
strong target buries a weak one 20 dB down at a completely different range.
Windowing trades main-lobe width for sidelobe level; the published figures
(Harris 1978, Table 1) and the levels measured in this repository on a
single bin-centred target are:
========== ============== ============== ==================
window published PSL measured PSL measured -3 dB lobe
========== ============== ============== ==================
rect -13.3 dB -13.25 dB 0.885 bin
hann -31.5 dB -31.47 dB 1.438 bin
hamming -42.7 dB -42.45 dB 1.301 bin
blackman -58.1 dB -58.11 dB 1.641 bin
========== ============== ============== ==================
Measured by transforming each window on its own with 2^18-point zero padding
and taking the highest lobe past the first null — that *is* the definition of
peak sidelobe level, so these are the module's own numbers, not copied ones.
Hamming lands 0.25 dB off the published figure because the published one is
for the optimal 0.53836/0.46164 pair; the 0.54/0.46 coefficients written here
are the textbook ones and this is what they actually give.
What it buys, measured end to end: a target 45 dB below a strong one, seven
range bins away, is undetectable unwindowed (its cell sits 24.6 dB down
in the leakage skirt and is not even a local maximum) and becomes a clean
local maximum at -43.6 dB with `hann`. That comparison is step 4 of
`examples/fmcw_range_doppler.py`.
*axis* is named by role — `"range"` (fast time, the last axis),
`"doppler" (slow time, the middle axis) or "both"` — never by number,
because a transposed cube is the mistake this naming is defending against.
The window is *not* folded into :func:range_doppler_map: keeping it a
separate op is what lets the sidelobe table above be measured as a
difference, and keeps the transform op a pure 2-D FFT.
Returns a new complex cube of the same shape. Raises `ValueError` on a
real-valued or malformed cube, or an unknown *window* / *axis*.
• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。
• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。
• 演算法的正典(作者・年份)與用途見上面的族使用指南。
• fmcw_range_doppler — py -3.11 examples/fmcw_range_doppler.py
beatcube 作為輸入)range_doppler_map · fmcw_range_profile · beamform_delay_sum · beamform_doa
process)range_doppler_map · range_doppler_peaks · fmcw_range_profile
*Provenance: rangedoppler.py — RANGEDOPPLER 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.