Documentation coverage¶

Every user-visible feature of Helia should have three things:

1. a tutorial: step by step, on a real capture, with screenshots, the exact settings, what to expect and what to do when it goes wrong;
2. a complete reference: every command line flag, API field and app control, with ranges and defaults;
3. a changelog entry that says how: the method, the references it follows and the measured effect, with a link to the tutorial.

This page records, feature by feature, where Helia stands against that rule. It is kept honest on purpose: a feature is Done only when all three columns are, and a gap is named so that it can be closed. The status is judged by a person, but two things are checked by cargo xtask docs --check (and cargo xtask coverage): every subcommand and long flag in the command line reference is mentioned in the guide (User guide, Step by step or How-to recipes), and every page linked from the table below exists.

The command line and API references are generated from the code, so they are complete by construction; the Reference column is only Partial where an app control (a slider range, a chip) is described in prose and not in a table.

How to read the cells: a link is the page that does the job. Partial says what is missing. Owner is the person or agent working on the gap: H-A is this documentation pass, H-B is the pass that is writing the tutorials listed against it, and an issue number means the feature itself is still being changed there.

The science outputs¶

The graphs and tables a stack can write. Each has a tutorial that reads it on a real capture and is listed with its files on Science outputs. Every one is a PNG with its data as CSV and JSON, drawn by helia stack --report DIR (or helia timelapse --report DIR), redrawn by helia plot KIND DIR, served by the API as GET /jobs/{id}/report/{file} and shown in the Science panel of the app. The kind in brackets is the argument of helia plot.

Frame quality (tutorial):

• the quality graph sorted, with the keep threshold (quality-sorted)
• the quality graph in capture order, kept and rejected, with the trend (quality-order)
• the histogram of the quality scores (quality-histogram)
• the global shift (x, y) of each frame, the drift and the path (shift-drift)
• the differential image motion, the seeing, over the capture (seeing-time)

Alignment points (tutorial):

• the point grid on the reference frame (ap-grid)
• the heatmap of the sharpness each point stacks (ap-quality)
• the heatmap of how much each point moves (ap-shift)
• the vector plot of the mean displacement of each point (ap-field)
• the vector plot of the residual against the finished stack, with --ap-residual (ap-residual)

Image science (tutorial):

• the power spectrum of stack, best frame and sharpened image, with the noise floors and the granulation and diffraction cut-offs (power-spectrum)
• the MTF-like transfer curves between them (mtf)
• the limb-darkening profile against the fitted law, with residuals (limb-profile)
• the limb edge, the fitted blur and the point spread function it implies (limb-psf)
• the histograms per channel with the clipping marked (histogram)
• the noise and the signal to noise (noise-snr)

Solar specifics (tutorial):

• the Stonyhurst heliographic grid with P, B0, L0 and solar north and east (grid-stonyhurst)
• the Carrington heliographic grid (grid-carrington)
• the sunspot overlay and group table, with --sunspots (sunspots.png; the method is in counting sunspots)
• the registration, brightness and derotation diagnostics of a time-lapse (timelapse-registration, timelapse-brightness, timelapse-derotation)