"""Stage 6: write the session's own METHODS.md. Every session directory gets an account of what was done to it and what came out, written for someone who was not there and has no access to the chat that produced it. That is the whole point of generating it rather than writing it by hand: a hand-written note is written once and then rots, while this is rebuilt from the actual results every time the pipeline runs. It records what was measured, not what was intended - including the things that did not work, because a session where the plate solve failed is more useful with that stated than with it omitted. """ import os from datetime import datetime, timezone import numpy as np import layout def _fmt_exposure(seconds): return f"{seconds / 60:.0f} min" if seconds >= 60 else f"{seconds:.0f} s" def write(session, results, verbose=True): """Compose METHODS.md from whatever the stages actually returned.""" stats = results.get("stats") or {} solve = results.get("solve") reference = results.get("reference") palette = session.palette now = datetime.now(timezone.utc).strftime("%Y-%m-%d %H:%M UTC") lines = [] add = lines.append add(f"# {session.target} - {session.telescope}") add("") add(f"Processed {now} by the pipeline in the " "[astrophotography](https://git.discworld.casa/laurence/astrophotography) " "repository (`pipeline/`). This file is generated: re-running the " "pipeline rewrites it from the actual results.") add("") # ---------------------------------------------------------- what is here add("## What was captured") add("") add("| Filter | Frames | Exposure | Binning | Total |") add("|---|---|---|---|---|") total = 0.0 for filt in session.filters: frames = session.by_filter(filt) exps = sorted({f.exptime for f in frames}) bins = sorted({f.binning for f in frames}) secs = sum(f.exptime for f in frames) total += secs add(f"| {filt} | {len(frames)} | " f"{'/'.join(f'{e:.0f} s' for e in exps)} | " f"{'/'.join(f'bin{b}' for b in bins)} | {_fmt_exposure(secs)} |") add(f"| **Total** | **{len(session.frames)}** | | | " f"**{_fmt_exposure(total)}** |") add("") add(f"Colour scheme: **{palette}**" + {"SHO": " - the Hubble palette, SII to red, Ha to green, OIII to blue", "HOO": " - Ha to red, OIII to green and blue", "LRGB": " - colour from R/G/B, detail from the deeper luminance", "RGB": " - no luminance channel, so brightness is synthesised from " "the colour channels", "MONO": " - a single filter, rendered as greyscale"}.get(palette, "")) add("") # -------------------------------------------------------- frame quality if stats: add("## Frame quality") add("") add("| Filter | Sky (ADU) | Noise (ADU) | Seeing (px) |") add("|---|---|---|---|") for filt in session.filters: vals = [stats[f.name] for f in session.by_filter(filt) if f.name in stats] if not vals: continue sky = np.median([v["sky"] for v in vals]) rms = np.median([v["rms"] for v in vals]) fwhm = np.median([v["fwhm"] for v in vals]) add(f"| {filt} | {sky:.1f} | {rms:.2f} | {fwhm:.2f} |") add("") # ---------------------------------------------------------- what was done add("## What was done") add("") add("1. **Ingest.** Archives uncompressed into `calibrated/`. Only the " "`calibrated-` set is extracted; the `raw-` archives stay zipped in " "`raw/` as untouched originals, because extracting both would put two " "copies of every frame into the stack.") add("2. **Measure.** Sky, noise and star sharpness per frame, with each " "frame's star list cached for the stages that follow.") if reference: add(f"3. **Register and stack.** Every frame aligned by matching star " f"patterns onto one reference - `{reference.name}` " f"({reference.filter}, the sharpest frame of the deepest filter) - " f"so all masters share a pixel grid and the colour image needs no " f"further alignment. Combined with a " f"{'sigma-clipped ' if len(session.frames) >= 3 else ''}" f"noise-weighted mean.") else: add("3. **Register and stack.**") if solve: add(f"4. **Plate solve.** Matched against Gaia DR3: " f"**{solve['nstars']} stars, {solve['residual_arcsec']:.2f} arcsec " f"residual**. The WCS is written into every master, so any position " f"measured from these images is quotable.") else: add("4. **Plate solve. FAILED for this session** - the star pattern " "match did not converge against Gaia. The images are unaffected, " "but nothing here carries sky coordinates, so positions cannot be " "measured from them.") add(f"5. **Colour.** Assembled as {palette}, with the sky background " "levelled by a plane fitted outside the target and the three channels' " "backgrounds forced neutral.") add("") # ------------------------------------------------------------ astrometry if solve: add("## Astrometry") add("") add(f"- Field centre: **{solve['centre']}**") add(f"- Plate scale: **{solve['scale']:.4f} arcsec/pixel**") add(f"- Field of view: {solve['fov_arcmin'][0]:.1f}' x " f"{solve['fov_arcmin'][1]:.1f}'") add(f"- Position angle: {solve['position_angle']:.2f} deg") add(f"- Residual: {solve['residual_px']:.2f} px " f"({solve['residual_arcsec']:.2f} arcsec) on {solve['nstars']} stars") add("") # ----------------------------------------------------------- honest limits add("## What limits this data") add("") shortest = min((sum(f.exptime for f in session.by_filter(x)) for x in session.filters), default=0) if len(session.frames) < 6: add(f"- **Very few frames ({len(session.frames)} in total).** With so " "few there is no meaningful outlier rejection, so satellite " "trails and cosmic rays survive into the masters.") if shortest < 600: add(f"- **Short integration** - the thinnest channel has only " f"{_fmt_exposure(shortest)}. No processing recovers signal that " "was never collected.") if palette == "RGB": add("- **No luminance channel**, so brightness is synthesised from the " "colour data and the result is noisier than an LRGB set of the " "same total exposure would be.") if palette == "MONO": add("- **A single filter**, so there is no colour information at all.") if not solve: add("- **No astrometric solution**, so nothing here can be used for " "positions or cross-matched against a catalogue.") fwhms = [v["fwhm"] for v in stats.values() if np.isfinite(v.get("fwhm", np.nan))] if fwhms and solve: seeing = float(np.median(fwhms)) * solve["scale"] add(f"- **Seeing of about {seeing:.1f} arcsec**, which sets the finest " "detail present regardless of how the data is processed.") add("") # ------------------------------------------------------------- directories add("## Where things are") add("") add("| Directory | Contents |") add("|---|---|") add("| `raw/` | exactly what the telescope delivered; untouched |") add("| `calibrated/` | the uncompressed calibrated frames |") add("| `stacks/masters/` | one registered, combined master per filter |") add("| `final/` | the finished image |") add("| `intermediates/` | caches; deletable, regenerated by a re-run |") add("") add("Re-run any stage by pointing the pipeline at this directory:") add("") add("```") add(f"set ASTRO_SESSION={session.root}") add("python pipeline/run.py") add("```") add("") path = os.path.join(session.root, "METHODS.md") with open(path, "w", encoding="utf-8") as fh: fh.write("\n".join(lines)) if verbose: print(f" -> METHODS.md") return path