Remote imaging, processing pipeline, and observing plans. Merged from itelescope + astro-pipeline.
laurence
015bff47fc
First stage of the generic pipeline. The existing scripts parse filenames, expecting calibrated-T32-...-Luminance-BIN2-W-300-001.fit, which works for exactly one telescope, one binning and one exposure length. Three of the four archived sessions have no luminance channel at all, so that approach cannot process them. session.py opens each frame and reads FILTER, EXPTIME, XBINNING, OBJECT and DATE-OBS instead. It groups frames by filter, works out which colour scheme the session supports (LRGB, RGB, SHO, HOO or mono), and writes a manifest. Filter aliases are mapped, so a header saying H-alpha, Halpha or HA all resolve to Ha. Three real defects were found by running it against the archive rather than by reasoning about it: Frame counts came out doubled. iTelescope ships every frame twice, as 'calibrated-*' with bias, dark and flat applied and 'raw-*' without, and extracting both put two copies of each frame into the stack. Only the calibrated archives are extracted now, with CALSTAT used as a header level safety net for sessions that were already extracted the old way. NGC 5128 now scans as 12/4/4/4, exactly matching the session processed by hand, which makes it a usable regression test. A re-mirror over the organised tree produced duplicates and mirror damage. An interrupted segmented download leaves DIRECTORIES named after the file being fetched - a directory called something.fit - plus .cyberducksegment parts. Anything that trusts a file extension will try to open a directory as a frame. Those are now skipped explicitly at discovery, ingest and scan, and byte-identical copies that a re-mirror puts back are removed as they are refiled. Two T20 archives are corrupt and cannot be extracted. That is real data loss, not a bug: the session has 14 of its 16 frames and the warning is printed rather than swallowed. Not yet done: NGC 6744 mixes bin1 luminance at 4096x4096 with bin2 colour at 2048x2048, so registration will need to resample onto a common grid rather than assuming every frame shares a shape. |
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|---|---|---|
| docs | ||
| itelescope | ||
| observing/eclipse-2026-menorca | ||
| pipeline | ||
| state | ||
| .gitignore | ||
| CLAUDE.md | ||
| README.md | ||
astrophotography
Everything to do with taking, processing and understanding astronomical images: the remote telescopes, the code that turns their frames into pictures and measurements, and the plans for observing in person.
Formed by merging the itelescope and astro-pipeline repositories, with the
history of both preserved.
Layout
| Directory | What it is |
|---|---|
| itelescope/ | The iTelescope.net remote telescope network: a review of every scope, a southern-target guide, the observing plans, and the points drain campaign |
| pipeline/ | The processing and analysis code. Calibration, stacking, plate solving, rendering and the science analyses |
| observing/ | Plans for observing in person. Currently the total solar eclipse of 12 August 2026 from Menorca |
| state/ | Project state under the Default Workflow: objective, current work, decisions, working notes |
| docs/ | The Default Workflow itself: branching, commits, documentation policy, cost control |
Start here
- Planning or reviewing a remote imaging run: itelescope/CAMPAIGN.md and itelescope/TELESCOPES.md
- Processing a session's data: pipeline/README.md
- What is happening right now: state/TODO.md
- Why something was done a particular way: state/DECISIONS.md
Where the image data lives
Not in this repository. A single calibrated frame is 61 MB and a session
runs to several gigabytes, so sessions stay on disk and the code finds them
through the ASTRO_SESSION environment variable:
set ASTRO_SESSION=...\NGC5128\20260721
python pipeline/stack.py
Each session directory carries its own METHODS.md describing what was done to
that data and what was found, written for a reader who was not there. The code
lives here; the pixels and the account of them live with the data.
Things learned the hard way
Recorded because each cost real time or real money, and because each is a requirement for anything built next rather than a curiosity:
- Measure whether a core is saturated before buying time to fix it. A foreground star 69 arcsec from Centaurus A's nucleus was mistaken for the galaxy, and a telescope booking was made to solve a problem that did not exist. Filter the stars out of the measurement first.
- Vet moving-object candidates in detector coordinates. Registration holds the sky still, so it drags sensor defects across the frame on perfectly straight, constant-rate tracks. Hot pixels are better-behaved asteroids than real asteroids. One cut took 141 confident spurious detections to zero.
- Never compare an aperture magnitude against a point-source catalogue without checking the source is a point. A resolved object looks exactly like a 2.8 magnitude outburst.
- Never fit a sky background to a field the target fills. A plane fitted around a large galaxy eats its halo, measured at -17.9 ADU/px. Fit the background and a source model together.
- A photographic ND filter is not a solar filter. It passes the infrared that carries the heat.