286 lines
12 KiB
Python
286 lines
12 KiB
Python
|
#!/usr/bin/env python
|
||
|
|
"""Fit the differential-rotation profile the archive actually shows.
|
||
|
|
|
||
|
|
fit_rotation.py # all six bands, built-in date spread
|
||
|
|
fit_rotation.py --bands 195 304 # a subset, e.g. corona vs chromosphere
|
||
|
|
fit_rotation.py --out fit.json # also record the numbers
|
||
|
|
|
||
|
|
The warp in :mod:`suvi.fillers` / :mod:`suvi.align` uses the Snodgrass & Ulrich
|
||
|
|
(1990) *photospheric plasma* profile. SUVI observes the EUV corona, which is known
|
||
|
|
to rotate more rigidly than the plasma below it, so this script measures what the
|
||
|
|
archive itself prefers: for real frame pairs 12 h and 24 h apart it scans
|
||
|
|
|
||
|
|
omega_sidereal(lat) = A + s * (B0 sin^2 lat + C0 sin^4 lat) [deg/day]
|
||
|
|
|
||
|
|
over (A, s) -- with B0, C0 the Snodgrass latitude terms -- warps the earlier frame
|
||
|
|
forward with each candidate profile, and scores it against the later frame on the
|
||
|
|
inner disc. s = 1 recovers Snodgrass & Ulrich exactly; s = 0 is rigid rotation.
|
||
|
|
|
||
|
|
Frames are vetted with the production judgment (`detectors.judge_file`) so a bad
|
||
|
|
frame cannot masquerade as solar evolution. Dates alternate into a held-out set
|
||
|
|
that never touches the fit; the fitted profile has to beat both s = 0 and s = 1 on
|
||
|
|
those dates before the numbers are worth baking into `suvi.align`.
|
||
|
|
"""
|
||
|
|
|
||
|
|
import argparse
|
||
|
|
import datetime
|
||
|
|
import glob
|
||
|
|
import json
|
||
|
|
import math
|
||
|
|
import os
|
||
|
|
import sys
|
||
|
|
|
||
|
|
import numpy as np
|
||
|
|
|
||
|
|
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
|
||
|
|
|
||
|
|
from suvi import detectors, fillers, fitsio, paths
|
||
|
|
|
||
|
|
#: Snodgrass & Ulrich (1990) latitude terms, deg/day; the shape being rescaled.
|
||
|
|
B0_TERM = -2.396
|
||
|
|
C0_TERM = -1.787
|
||
|
|
|
||
|
|
#: Candidate equatorial sidereal rates, deg/day. Snodgrass & Ulrich's 14.713 sits
|
||
|
|
#: mid-range; the ends are implausible enough to flag a broken measurement.
|
||
|
|
A_GRID = np.arange(13.75, 16.0, 0.25)
|
||
|
|
#: Candidate scales on the latitude terms. 1 = full plasma differential, 0 = rigid.
|
||
|
|
S_GRID = np.arange(0.0, 1.5, 0.25)
|
||
|
|
|
||
|
|
#: Gap lengths to measure across, seconds.
|
||
|
|
GAPS = (12 * 3600, 24 * 3600)
|
||
|
|
|
||
|
|
#: Inner-disc mask: far enough from the limb that foreshortening and the corona's
|
||
|
|
#: non-co-rotating off-disc glow do not dominate the score.
|
||
|
|
INNER_RHO2 = 0.81
|
||
|
|
|
||
|
|
#: How far past the nominal start time to keep looking for a usable frame.
|
||
|
|
SEARCH_SLOTS = 30
|
||
|
|
|
||
|
|
|
||
|
|
def build_date_list(first="2019-12-15", last="2025-03-15", every_months=3):
|
||
|
|
"""Mid-month dates every `every_months` months, hitting the B0 extremes.
|
||
|
|
|
||
|
|
March and September (B0 = -/+7.25 deg) are in the cycle, so a B0-sign or
|
||
|
|
tilt-handling defect cannot hide behind a mid-latitude-free sample.
|
||
|
|
"""
|
||
|
|
start = datetime.date.fromisoformat(first)
|
||
|
|
stop = datetime.date.fromisoformat(last)
|
||
|
|
dates, month = [], start
|
||
|
|
while month <= stop:
|
||
|
|
dates.append(month.isoformat())
|
||
|
|
year, next_month = month.year, month.month + every_months
|
||
|
|
while next_month > 12:
|
||
|
|
year, next_month = year + 1, next_month - 12
|
||
|
|
month = datetime.date(year, next_month, 15)
|
||
|
|
return dates
|
||
|
|
|
||
|
|
|
||
|
|
def split_holdout(dates, every=3):
|
||
|
|
"""(fit_dates, holdout_dates): every `every`-th date is held out."""
|
||
|
|
fit = [d for i, d in enumerate(dates) if i % every != every - 1]
|
||
|
|
held = [d for i, d in enumerate(dates) if i % every == every - 1]
|
||
|
|
return fit, held
|
||
|
|
|
||
|
|
|
||
|
|
def profile_rate(a, s, latitude_rad, synodic=True):
|
||
|
|
"""The candidate profile, same convention as :func:`suvi.fillers.rotation_rate`."""
|
||
|
|
sin2 = np.sin(latitude_rad) ** 2
|
||
|
|
rate = a + s * (B0_TERM * sin2 + C0_TERM * sin2**2)
|
||
|
|
return rate - fillers.EARTH_ORBIT_DEG_PER_DAY if synodic else rate
|
||
|
|
|
||
|
|
|
||
|
|
def refine_minimum(grid, errors):
|
||
|
|
"""Parabolic refinement of a 1-D sampled minimum; clamped to the grid ends."""
|
||
|
|
k = int(np.argmin(errors))
|
||
|
|
if k == 0 or k == len(grid) - 1:
|
||
|
|
return float(grid[k])
|
||
|
|
a, b, c = errors[k - 1], errors[k], errors[k + 1]
|
||
|
|
denominator = a - 2 * b + c
|
||
|
|
if denominator <= 0:
|
||
|
|
return float(grid[k])
|
||
|
|
step = grid[1] - grid[0]
|
||
|
|
return float(grid[k] + 0.5 * (a - c) / denominator * step)
|
||
|
|
|
||
|
|
|
||
|
|
def find_frame(satellite, wavelength, t_start):
|
||
|
|
"""First usable frame at or after `t_start`, or (None, ...) if none nearby.
|
||
|
|
|
||
|
|
Walks forward slot by slot so a routine per-slot outage does not discard the
|
||
|
|
whole date, and vets with the production judgment so a dark or corrupt frame
|
||
|
|
cannot enter the fit as fake solar evolution.
|
||
|
|
"""
|
||
|
|
root = paths.data_root()
|
||
|
|
for step in range(SEARCH_SLOTS):
|
||
|
|
t = t_start + step * paths.CADENCE
|
||
|
|
day = datetime.datetime.fromtimestamp(t, datetime.timezone.utc)
|
||
|
|
stamp = day.strftime("%Y%m%dT%H%M%S")
|
||
|
|
pattern = os.path.join(
|
||
|
|
root, f"goes{satellite:d}", "l2", "data", f"suvi-l2-ci{wavelength:03d}",
|
||
|
|
f"{day.year:04d}", f"{day.month:02d}", f"{day.day:02d}",
|
||
|
|
f"dr_suvi-l2-ci{wavelength:03d}_g{satellite:d}_s{stamp}Z_*.fits",
|
||
|
|
)
|
||
|
|
for path in sorted(glob.glob(pattern)):
|
||
|
|
slot = (satellite, wavelength, t)
|
||
|
|
if detectors.judge_file(slot, path).verdict == detectors.BAD:
|
||
|
|
continue
|
||
|
|
image, error = fitsio.read_image(path)
|
||
|
|
if image is None or image.shape != (1280, 1280):
|
||
|
|
continue
|
||
|
|
values, _ = fitsio.scan_header(path)
|
||
|
|
return fillers._finite(image), values, t
|
||
|
|
return None, None, None
|
||
|
|
|
||
|
|
|
||
|
|
def pair_surface(source, target, header, delta_seconds):
|
||
|
|
"""Relative error surface over (A_GRID, S_GRID) for one frame pair.
|
||
|
|
|
||
|
|
Scores are inner-disc MSE in asinh-stretched units, normalised by the pair's
|
||
|
|
own best so dates with different activity levels weigh equally, and the pair's
|
||
|
|
time gap is taken from the frames' actual observation times.
|
||
|
|
"""
|
||
|
|
height, width = target.shape
|
||
|
|
radius = fillers._disc_radius_pixels(header, target.shape)
|
||
|
|
crpix1 = float(header.get("crpix1", (width + 1) / 2.0)) - 1.0
|
||
|
|
crpix2 = float(header.get("crpix2", (height + 1) / 2.0)) - 1.0
|
||
|
|
grid_x, grid_y = np.meshgrid(np.arange(width), np.arange(height))
|
||
|
|
rho2 = ((grid_x - crpix1) ** 2 + (grid_y - crpix2) ** 2) / radius**2
|
||
|
|
inner = rho2 < INNER_RHO2
|
||
|
|
|
||
|
|
scale = 0.1 * max(float(np.median(target[inner])), 1e-6)
|
||
|
|
stretched_target = np.arcsinh(target / scale)
|
||
|
|
|
||
|
|
surface = np.zeros((len(A_GRID), len(S_GRID)))
|
||
|
|
original = fillers.rotation_rate
|
||
|
|
try:
|
||
|
|
for i, a in enumerate(A_GRID):
|
||
|
|
for j, s in enumerate(S_GRID):
|
||
|
|
fillers.rotation_rate = (
|
||
|
|
lambda lat, synodic=True, a=a, s=s: profile_rate(a, s, lat, synodic)
|
||
|
|
)
|
||
|
|
warped, visible = fillers._warp(source, header, delta_seconds, True)
|
||
|
|
mask = inner & visible
|
||
|
|
difference = np.arcsinh(warped / scale) - stretched_target
|
||
|
|
surface[i, j] = float(np.mean(difference[mask] ** 2))
|
||
|
|
finally:
|
||
|
|
fillers.rotation_rate = original
|
||
|
|
minimum = surface.min()
|
||
|
|
return surface / minimum if minimum > 0 else surface
|
||
|
|
|
||
|
|
|
||
|
|
def measure_band(satellite, wavelength, dates, verbose=True):
|
||
|
|
"""Per-pair relative surfaces for one band: {date: {gap_seconds: surface}}."""
|
||
|
|
surfaces = {}
|
||
|
|
for date in dates:
|
||
|
|
t0 = int(datetime.datetime.fromisoformat(date + "T00:00:00+00:00").timestamp())
|
||
|
|
source, _, t_source = find_frame(satellite, wavelength, t0)
|
||
|
|
if source is None:
|
||
|
|
continue
|
||
|
|
for gap in GAPS:
|
||
|
|
target, header, t_target = find_frame(satellite, wavelength, t_source + gap)
|
||
|
|
if target is None:
|
||
|
|
continue
|
||
|
|
surface = pair_surface(source, target, header, float(t_target - t_source))
|
||
|
|
surfaces.setdefault(date, {})[gap] = surface
|
||
|
|
if verbose:
|
||
|
|
k = np.unravel_index(np.argmin(surface), surface.shape)
|
||
|
|
print(f" ci{wavelength:03d} {date} +{gap // 3600:2d}h: "
|
||
|
|
f"pair argmin A={A_GRID[k[0]]:.2f} s={S_GRID[k[1]]:.2f}",
|
||
|
|
flush=True)
|
||
|
|
return surfaces
|
||
|
|
|
||
|
|
|
||
|
|
def fit_from_surfaces(surfaces):
|
||
|
|
"""Aggregate relative surfaces and refine the (A, s) minimum."""
|
||
|
|
total = np.mean([s for by_gap in surfaces.values() for s in by_gap.values()], axis=0)
|
||
|
|
i, j = np.unravel_index(np.argmin(total), total.shape)
|
||
|
|
a = refine_minimum(A_GRID, total[:, j])
|
||
|
|
s = max(0.0, refine_minimum(S_GRID, total[i, :]))
|
||
|
|
return a, s, total
|
||
|
|
|
||
|
|
|
||
|
|
def holdout_score(surfaces, a, s):
|
||
|
|
"""Mean relative error of a profile on held-out surfaces, via interpolation."""
|
||
|
|
scores = []
|
||
|
|
for by_gap in surfaces.values():
|
||
|
|
for surface in by_gap.values():
|
||
|
|
ai = np.clip(np.interp(a, A_GRID, np.arange(len(A_GRID))), 0, len(A_GRID) - 1)
|
||
|
|
sj = np.clip(np.interp(s, S_GRID, np.arange(len(S_GRID))), 0, len(S_GRID) - 1)
|
||
|
|
i0, j0 = int(ai), int(sj)
|
||
|
|
i1, j1 = min(i0 + 1, len(A_GRID) - 1), min(j0 + 1, len(S_GRID) - 1)
|
||
|
|
fa, fs = ai - i0, sj - j0
|
||
|
|
value = (surface[i0, j0] * (1 - fa) * (1 - fs)
|
||
|
|
+ surface[i1, j0] * fa * (1 - fs)
|
||
|
|
+ surface[i0, j1] * (1 - fa) * fs
|
||
|
|
+ surface[i1, j1] * fa * fs)
|
||
|
|
scores.append(value)
|
||
|
|
return float(np.mean(scores)) if scores else math.nan
|
||
|
|
|
||
|
|
|
||
|
|
def main(argv=None):
|
||
|
|
parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
|
||
|
|
parser.add_argument("--satellite", type=int, default=16)
|
||
|
|
parser.add_argument("--bands", type=int, nargs="*", default=list(paths.WAVELENGTHS))
|
||
|
|
parser.add_argument("--first", default="2019-12-15")
|
||
|
|
parser.add_argument("--last", default="2025-03-15")
|
||
|
|
parser.add_argument("--holdout-every", type=int, default=3)
|
||
|
|
parser.add_argument("--out", help="Write the fitted numbers to this JSON file")
|
||
|
|
args = parser.parse_args(argv)
|
||
|
|
|
||
|
|
dates = build_date_list(args.first, args.last)
|
||
|
|
fit_dates, held_dates = split_holdout(dates, args.holdout_every)
|
||
|
|
print(f"{len(fit_dates)} fit dates, {len(held_dates)} held out, "
|
||
|
|
f"gaps {[g // 3600 for g in GAPS]} h, satellite G{args.satellite}")
|
||
|
|
|
||
|
|
report = {"satellite": args.satellite, "fit_dates": fit_dates,
|
||
|
|
"holdout_dates": held_dates, "bands": {}}
|
||
|
|
pooled_fit, pooled_held = [], []
|
||
|
|
for wavelength in args.bands:
|
||
|
|
fit_surfaces = measure_band(args.satellite, wavelength, fit_dates)
|
||
|
|
held_surfaces = measure_band(args.satellite, wavelength, held_dates)
|
||
|
|
if not fit_surfaces:
|
||
|
|
print(f"ci{wavelength:03d}: no usable pairs, skipped")
|
||
|
|
continue
|
||
|
|
a, s, _ = fit_from_surfaces(fit_surfaces)
|
||
|
|
entry = {
|
||
|
|
"A_sidereal": round(a, 3), "s": round(s, 3),
|
||
|
|
"pairs_fit": sum(len(v) for v in fit_surfaces.values()),
|
||
|
|
"pairs_holdout": sum(len(v) for v in held_surfaces.values()),
|
||
|
|
"holdout_fitted": holdout_score(held_surfaces, a, s),
|
||
|
|
"holdout_snodgrass": holdout_score(held_surfaces, 14.713, 1.0),
|
||
|
|
"holdout_rigid": holdout_score(held_surfaces, 14.713, 0.0),
|
||
|
|
}
|
||
|
|
report["bands"][wavelength] = entry
|
||
|
|
pooled_fit.append(fit_surfaces)
|
||
|
|
pooled_held.append(held_surfaces)
|
||
|
|
print(f"ci{wavelength:03d}: A={a:.3f} s={s:.3f} "
|
||
|
|
f"holdout fitted/snodgrass/rigid = "
|
||
|
|
f"{entry['holdout_fitted']:.4f}/{entry['holdout_snodgrass']:.4f}"
|
||
|
|
f"/{entry['holdout_rigid']:.4f} ({entry['pairs_fit']} pairs)")
|
||
|
|
|
||
|
|
if pooled_fit:
|
||
|
|
merged_fit = {f"{k}#{i}": v for i, s in enumerate(pooled_fit) for k, v in s.items()}
|
||
|
|
merged_held = {f"{k}#{i}": v for i, s in enumerate(pooled_held) for k, v in s.items()}
|
||
|
|
a, s, _ = fit_from_surfaces(merged_fit)
|
||
|
|
report["shared"] = {
|
||
|
|
"A_sidereal": round(a, 3), "s": round(s, 3),
|
||
|
|
"holdout_fitted": holdout_score(merged_held, a, s),
|
||
|
|
"holdout_snodgrass": holdout_score(merged_held, 14.713, 1.0),
|
||
|
|
"holdout_rigid": holdout_score(merged_held, 14.713, 0.0),
|
||
|
|
}
|
||
|
|
print(f"\nshared profile: A={a:.3f} s={s:.3f} "
|
||
|
|
f"holdout fitted/snodgrass/rigid = "
|
||
|
|
f"{report['shared']['holdout_fitted']:.4f}"
|
||
|
|
f"/{report['shared']['holdout_snodgrass']:.4f}"
|
||
|
|
f"/{report['shared']['holdout_rigid']:.4f}")
|
||
|
|
b, c = round(s * B0_TERM, 3), round(s * C0_TERM, 3)
|
||
|
|
print(f"constants for suvi.align: A={round(a, 3)} B={b} C={c}")
|
||
|
|
|
||
|
|
if args.out:
|
||
|
|
with open(args.out, "w") as handle:
|
||
|
|
json.dump(report, handle, indent=2)
|
||
|
|
print(f"wrote {args.out}")
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
main()
|