Remote imaging, processing pipeline, and observing plans. Merged from itelescope + astro-pipeline.
laurence
2f268c7ca9
The seeded solver starts from the header's pointing, scale and roll angle and matches against Gaia. That works whenever the image and the catalogue hold recognisably the same stars, and fails when they do not: a single 60 second narrowband frame over a four degree field records a sparse, shallow population that overlaps poorly with any magnitude slice of Gaia, and no amount of window sliding fixes a population mismatch. A blind solver does not care about any of that. It builds geometric hashes from the image's own stars and looks them up in pre-built indexes, so it needs no pointing, no scale and no orientation - only pixels. blind.py drives nova.astrometry.net through astroquery, passing the plate scale as a hint where one is known, which turns a search over every possible scale into a search over one. Two properties worth stating plainly. It needs a free API key, and without one it says so clearly and the pipeline continues unsolved rather than failing. And it uploads the image to a third-party service, which is fine for these targets but is a fact worth knowing before pointing it at something unpublished. The result is verified rather than trusted. Whatever the service returns is matched back against Gaia locally and put through the same gate as the seeded solver - 40 stars and 1.5 px - so a solution has to be good, not merely returned. A wrong WCS remains worse than no WCS whoever produced it. |
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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.