fmcw_design — RANGEDOPPLER design op

• Data kinds: none → table (an op determined by its arguments alone — it takes no image or data input)

• Call: import fullseye as fs; fs.ledger.fmcw_design(n_samples=64, n_chirps=32, sample_rate_hz=10000000.0, slope_hz_per_s=20000000000000.0, chirp_period_s=5e-05, wavelength_m=0.0038934, n_antennas=1, element_spacing_m=None) (to call the implementation directly, import rangedoppler; rangedoppler.fmcw_design(n_samples=64, n_chirps=32, sample_rate_hz=10000000.0, slope_hz_per_s=20000000000000.0, chirp_period_s=5e-05, wavelength_m=0.0038934, n_antennas=1, element_spacing_m=None); from the registry, opsrangedoppler.get("fmcw_design"))

Usage

Bin widths, resolutions and aliasing limits of an FMCW configuration.

The paper answer to "will this waveform see what I care about?", with no data and no simulation — the stance visiondesign takes for optics. Every number is closed form:

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quantity formula

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swept bandwidth B = S * N_s / f_s

range bin / resolution dR = c / (2B) = c*f_s / (2*S*N_s)

max unambiguous range R_max = c*f_s / (2S) (= N_s * dR)

beat frequency per metre 2S/c

velocity bin / resolution dv = lambda / (2*N_c*T_c)

max unambiguous velocity v_max = lambda / (4*T_c) (= N_c*dv/2)

Doppler phase per (m/s) 4*pi*T_c / lambda rad per chirp

coherent processing interval N_c * T_c

max unambiguous angle asin(lambda / (2d))

angular resolution (boresight) 0.886 * lambda / (N_a * d) ============================== ============================================

The two "max" figures are hard aliasing limits, and they are the same

numbers fmcw_beat_simulate refuses to cross. The angular resolution is the 3 dB beamwidth of a uniform linear array at boresight (Van Trees 2002, §2.4); it widens as 1/cos(theta) off boresight, which this does not report because it is a function, not a number.

cube_elements and cube_mebibytes are included because "small input, huge allocation" is the failure mode of this family: the cube grows as N_a * N_c * N_s and complex128 is 16 bytes a sample.

Returns a dict. Raises ValueError on a non-positive or non-finite parameter, a wavelength over MAX_WAVELENGTH_M, or a count outside its cap.

>>> d = fmcw_design()

>>> round(d["range_bin_m"], 6), round(d["max_unambiguous_velocity_ms"], 6)

(1.171064, 19.467)

Detailed usage guide

• fmcw_range_doppler family guide

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.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• fmcw_range_doppler — py -3.11 examples/fmcw_range_doppler.py

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

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Same category (design)

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*Provenance: rangedoppler.py — RANGEDOPPLER 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.