Planner finding charts

Create printable finding charts from the already completed final Planner ephemeris without recomputing comet positions.

Documented finding-chart workflow: Generate maps is single-comet. It reuses final Planner rows, performs deferred authoritative N-body refinement for the physical track, and renders one overview/index page followed by A4 landscape detail sheets.

Prerequisites

Run Generate ephemeris first and use a fresh final Planner result. Only comets present in that final ephemeris can be selected for map preparation.

When the local TYC2 catalogue is not yet validated, the Generate maps workflow can perform the required setup/validation on demand. GSC 1.1 data are retrieved and validated through the supported catalogue path as required by the prepared sheets.

Current workflow

Generate a fresh Planner ephemeris.
Choose Generate maps.
Select exactly one map-eligible comet.
If a required local catalogue is missing or damaged, choose Download local, Use online, or Cancel.
KOPR freezes one immutable single-target document and performs deferred physical-track refinement.
Inspect the overview/index and detail pages in Preview.
Choose Save PDF... and atomically export the same prepared document.

Coordinates and catalogues

Final Planner N-body rows are reused; missing track epochs are computed only after explicit Generate maps.
Local catalogue roots are fixed: ./koprtyc2 and ./koprybsc5. Arbitrary TYC directory selection is retired.
Detail-star fusion uses deterministic priority Yale > TYC2 > GSC1.1.
The overview independently acquires TYC2+Yale stars to 8.0 mag; GSC is not used for that completeness claim. Online VizieR acquisition applies server-side VTmag filtering so catalogue row truncation does not silently reduce the requested depth.
Yale B−V is provenance only. Finding charts are permanently monochrome.

Bounded physical-track refinement

Each drawable segment is checked with authoritative topocentric N-body probes at 1/4, 1/2 and 3/4 of the time interval. If projected page-space error exceeds 0.25 mm, the worst probe becomes an unannotated geometry vertex and the affected segment is measured again.

Hard bounds are depth 8, 4096 N-body epochs per operation and chunks of 32. Fallback two-body geometry is rejected. This is a bounded physical-probe contract, not an analytical proof of continuum error between probe positions.

Physical chronology is strictly increasing epoch_utc; requested_date is annotation/calendar provenance only.

Detail sheets and overview/index

All detail pages use A4 landscape canonical footprints. The first physical page is an overview/index with the complete track, direction of time, bright-star/constellation context and numbered footprints D1, D2, …; detail pages carry the matching Dn identity.

Sheet partitioning first minimizes the required number of detail sheets and then balances temporal/annotation load where the geometry allows it. This avoids unnecessarily lopsided splits while leaving the physical trajectory and catalogue science unchanged.

Adaptive packing can produce a final/remainder detail sheet containing only dense physical-track vertices. Such a sheet is valid: it inherits the already validated parent photometric star limit. Unannotated geometry placeholder values are never interpreted as a request for deeper star-catalogue data.

Date-label placement is geometry-aware. Normal full-mode labels use one coherent side of the local track normal; when the projected track is too dense/short for readable text, the chart can show endpoint-only date text while retaining the full physical track and all markers. Substantially displaced labels use thin leader lines.

The overview is one square TAN projection: 30° by default, expanding in 1° steps only when needed to include the complete track and all detail footprints, with a hard maximum of 60°. A wider requirement fails closed and asks for a shorter interval.

Immutable Preview identity

Preparation freezes the exact scene content and a SHA-256 identity. After Preview, export performs no catalogue queries, ephemeris recomputation, track re-segmentation, orientation recomputation or label-placement recomputation.

Preview therefore represents the scene that will be written to PDF, rather than a loosely related pre-render.

Monochrome print rendering

Finding charts are black-and-white. Constellation figures are thin black lines beneath stars and the comet track. Overview constellation lines, D-footprint outlines, the comet track and time arrow are clipped to the overview rectangle.

On the overview, 8.0 mag is the current faint catalogue limit. The magnitude legend uses the same symbol-size resolver as rendered overview stars, and brighter stars increase monotonically in size. D labels are placed outside every footprint while remaining inside the overview frame.

Save PDF… remembers the last valid directory selected during the current Planner session. The next finding-chart save starts there; this is a session convenience, not a persistent setting across application restarts.

Catalogue, cache and cancellation hardening

TYC2 cancellation stops promptly and must not publish a partial validation cache.
VizieR cancellation stops the server-fallback sequence promptly.
The validated TYC2 cache uses schema v2 and SHA-256 binding; same-size/same-mtime source mutation invalidates the cache and active catalogue.
A complete local TYC2 installation contains all 36 expected catalogue tiles.
GSC cached data are revalidated for checksum, spherical footprint, magnitude bounds and Class = 0 provenance.
Weak cache schemas are rejected rather than silently trusted.

Related chapters

Observation Planner · Comet element source roles · Troubleshooting · Performance