Export to JHelioviewer

Qorona output drops into JHelioviewer for viewing and overlay on observed imagery, through two registered routes: WCS-registered FITS for the image products, and SunJSON geometry for field lines. Both need a timestamp (--timestamp, or a volume baked with one): it sets the observation time the file is registered at.

Route	Commands	JHelioviewer layer
FITS raster	render --export fits, wl --export fits	image layer, WCS-registered
SunJSON field lines	fieldlines --export sunjson, export-lines	Connection Layer, 3-D lines

FITS rasters

--export fits writes the quantitative frame beside the PNG: render stores the LOS-averaged log₁₀ Q⊥ (float32), wl the display frame plus the raw pB/total frames as extensions. Drop the file into JHelioviewer and it registers at the correct scale, orientation, position, and time; sunpy.map.Map reads the same registration for scripted analysis. The run's full provenance rides in the FITS header.

• --observer earth points the camera from the real Earth viewpoint at the timestamp, so the overlay matches Earth-based observations exactly (any named observer works the same way; see Camera).
• The disk: with the default eclipse occulter it stays NaN, transparent in JHelioviewer, so real disk imagery shows through; render --occult composite fills it with the near-side surface Q instead.

Field lines as SunJSON

SunJSON is the geometry format of JHelioviewer's Connection Layer: drop the .json onto a running JHelioviewer and the bundle appears in 3-D, at its timestamp on the timeline. Lines carry the polarity palette of the field-line view (open warm/cool by inner-foot B_r sign, closed neutral grey) and an open/closed topology tag.

• qorona fieldlines ... --export sunjson: exactly the drawn bundle beside the PNG, with the same seeding, selection (--show), and colours as the image, the eclipse look included.
• qorona export-lines: a self-contained full trace on a uniform longitude/latitude seed grid (--seeds N_THETA N_PHI, default 100x100; --seed-radius moves the seed sphere); no camera involved.

qorona export-lines data/coconut_corona.CFmesh.xz -o data/coconut_fieldlines.json \
    --timestamp 2025-10-09T18:19:52 --seeds 40 80

The solution frame

Both routes write positions in Carrington coordinates, which is what JHelioviewer expects, and both start from the solution's own frame: the FITS observer and the SunJSON longitudes are shifted by the declared frame's offset (--frame, see Camera), zero for a Carrington frame and L0 for a Stonyhurst one. The frame is therefore part of the registration: exported under the wrong one, a product lands up to 360 degrees off in longitude, and nothing in the file reveals it. Without a declaration Qorona falls back to Carrington and warns.