22 deg halo
The common ring around the sun and the scale reference for the atlas.
circle(sun, R22)
rendered-corescale-lock
Vocabulary ledger, not the atlas
Halo Vocabulary Legend
A public dictionary for the optical phenomena and site terms around the Sundog atlas. The atlas is the visual geometry page; the h-of-x math page walks through the first promoted inverse equation. This legend keeps the broader vocabulary honest by separating rendered primitives, optional labels, named-only literature, and not-modeled halo families. Comparator terms such as posterior, misspecification, and substrate-conditional evidence belong on the alignment primer.
Rendered Atlas Vocabulary
These are the primitives shown or named in the current atlas. Only the parhelion-offset route is promoted as an inverse measurement handle.
46 deg halo
A larger halo used as context for CZA, supralateral, and infralateral vocabulary.
circle(sun, R46)
rendered-coreforward vocabulary
Sundog / parhelion
Bright flanking spots on the parhelic circle. The offset recovers sun altitude when the anchors are eligible.
offset = R22 / cos(h)
rendered-corepromoted inverse
Parhelic circle
The horizontal belt through the sun and parhelia. It is rendered, but not promoted as a hidden-state handle.
circle through sun and parhelia
rendered-coreprimitive QA
Circumzenithal arc
The high smile-shaped arc. The current route is visibility-gated; pre-A1b anchors need rechecking before proof use.
visible when h < 32.196 deg
rendered-corecoverage-gated inverse
Supralateral arc
High arc near the 46 deg halo/CZA region. The inverse route failed coverage and structural-discrimination gates.
46 deg family context
rendered-optionalnot promoted
Upper tangent arc
Column-crystal tangent vocabulary above the 22 deg halo. It remains useful for logo language, not inverse proof.
tangent-family candidate
rendered-optionalC5/C6/C7 tension
Suncave Parry arc
A Parry-family cap near the upper tangent arc. It is optional vocabulary with weak photo support.
Parry-oriented family
rendered-optionalweak evidence
Lower tangent arc
The lower counterpart of the upper tangent family, tied to low-altitude/observer geometry.
22 deg lower tangent family
rendered-optionalpose-bound
Parry supralateral arc
Parry-family shoulders near the 46 deg top region. Coverage and weak evidence blocked promotion.
Parry + 46 deg family
rendered-optionalnot promoted
Infralateral arcs
Lower-side 46 deg family vocabulary. Present as periphery language, not a calibrated inverse route.
46 deg lower-side family
rendered-optionalphoto-partial
Sun pillar
A vertical light column from plate-crystal reflection. The atlas renders it as stylized visual vocabulary.
plate-crystal reflection
rendered-corestylized generator
Named, Not Yet Modeled
These rows keep the vocabulary visible without pretending the atlas already accounts for every halo family.
Parry-family arcs
Includes suncave, sunvex, and Parry supralateral members. Some are optional labels today; the family still needs subrows and HaloSim receipts.
named-onlypartial optional render
Pyramidal / odd-radius halos
Faint odd-radius rings from pyramidal ice crystals. HaloSim reproduces the family, but the atlas does not model it and the quantitative ring-isolation route topped out below promotion.
not-modeledP2 simulated candidatenot atlas-modeled
Lowitz arcs
Arcs from rotating plate orientations, historically contested and now photographically observed. Not modeled here yet.
named-onlyHaloSim candidate
Antisolar features
Anthelion, anthelic arcs, paranthelia, and 120 deg parhelia live opposite or far around from the sun.
not-modelednamed-only
Sub-horizon halos
Subsun and subparhelia require aircraft, mountain, or below-horizon observer geometry.
named-onlyobserver extension
Circumhorizon arc
A high-sun plate-crystal arc sometimes called a fire rainbow. It is outside the current sundog-facing regime.
not-modelednamed-only
Sundog Method Terms
These are the project terms that used to be repeated on the homepage. The short version lives here; the math version lives on h-of-x, and the lab posture lives on About.
Trace
The indirect signal left in the world: parhelion offset, detector intensity, shadow, pressure field, deformation, local acceleration, or behavior wake.
method termindirect signal
Transformation
The rule that makes the trace usable. Sometimes it is closed form, like R22 / cos(h); sometimes it is a bounded controller or measured operating envelope.
method termroute to action
Boundary
The point where the trace stops being enough. A credible indirect route names the boundary where it should fail instead of smoothing that failure into a story.
method termfailure visible
This legend is a map of current project status, not a claim that Sundog has solved every halo. Phase 14 fills the accounting matrix; Phase 15 is reserved for speculative or unphotographed halos that need math, brute-force ray tracing, atlas comparison, and HaloSim receipts before promotion.