sksat

Express coordinate reference frames, time scales, and state representations in the type system, and test them with property-based tests — durable design guidance for orts/arika that holds whether you extend the current types or redesign them. Use when implementing, refactoring, or rethinking frame/scale code: adding a frame, scale, or transform; typing vectors, epochs, covariances, or rotations; deciding which time scale a transform takes; isolating EOP dependencies; choosing an interpolation space; or writing tests for rotation and scale-conversion invariants — and also when reviewing or verifying frame/scale code for type-safety. Companion to `coordinate-time-systems`, which covers the domain concerns (which frame/scale/representation, the traps).

Reason about coordinate reference frames and time scales correctly (any astrodynamics work) — which frame/scale/representation a value is actually in, the concerns to resolve before trusting it, and what to look up. Use when interpreting or choosing frames (ECI/ECEF, GCRS/ITRS/CIRS/TIRS, J2000/EME2000, TEME, ICRF, LVLH/RTN/RSW, body-fixed), time scales (TAI/UTC/UT1/TT/TDB/GPS), or state representations (Cartesian/Keplerian/equinoctial); or when reasoning about frame/scale conversions, covariance transforms, interpolation, leap seconds, ERA/GMST/GAST, EOP/ΔUT1, polar motion, frame bias, or realizations — and also when reviewing or verifying frame/time/coordinate work (use it as a checklist of the traps, even for code you could write unaided). The companion skill `coordinate-time-implementation` covers expressing and testing these in orts/arika code.

Run an external AI code review to get independent feedback on code changes. Use this skill when the user asks for a code review, says "コードレビューして", "レビュー", "変更を見て", "code review", or wants external feedback on their recent commits or uncommitted changes.

A knowledgeable neighbor who offers a fresh perspective on architecture, design decisions, and test strategy. Use proactively when a second opinion would improve quality, or when the user says "別の視点が欲しい", "設計を相談したい", "相談", "smart-friend に聞いて", or asks for feedback on their approach.

Reference for generating Orekit cross-validation fixtures. Covers orekit-jpype setup, force model matching, CSSI space weather, and fixture generation patterns.

Guidelines for E2E testing the orts viewer with Playwright. Covers DuckDB query-level data verification, canvas pixel analysis, and common pitfalls.

Check if package names are available on crates.io and npm. Use when naming a new library or crate.

Resume from a previous interrupted Claude Code session. Checks conversation logs, git status, and pending work to reconstruct context.

Full pipeline for analyzing a new SOLAR LINE episode — from subtitle extraction through orbital analysis to published report. Use when starting analysis of a new episode.

Review a SOLAR LINE episode or summary report for quality, accuracy, and readability. Checks data integrity, Japanese text quality, and orbital mechanics correctness.

Extract and process subtitles from a SOLAR LINE episode video. Supports YouTube VTT download, Whisper STT, video OCR, and dialogue line extraction.

Consult OpenAI Codex as a trusted friend for design review, architecture feedback, or technical advice. Use when the user asks to consult Codex or wants a second opinion.

Analyze Claude Code session costs using ccusage. Shows token distribution, per-model breakdown, cache efficiency, and optimization recommendations.

Record a smooth per-layer timelapse of a Bambu A1 mini print — the "object grows, nozzle parked out of the way" look — using the printer's NATIVE Smooth timelapse (firmware-safe park + Z-lift), captured by `bambu serve`'s in-process grabber from one or more EXTERNAL cameras (the A1's built-in camera is dead on this unit). Use this whenever the user wants a timelapse, a "smooth"/"park-synced" timelapse, the head to step aside for the camera each layer, a multi-camera/multi-angle capture, or asks why a timelapse print detached / looks scraped / came out as a flat plate. Covers slicing for timelapse, arming it at print start, the serve capture API, and assembling the video. Do NOT use it for plain slicing with no timelapse (use bambu-slice), a one-off camera snapshot, or live print control (pause/resume/stop).

Start a print on the Bambu Lab A1 mini SAFELY — the part that goes wrong is the filament SOURCE. Use whenever the user wants to start/run a print from an already-sliced .gcode.3mf (upload + `job start`, via the `bambu` CLI or `bambu serve`), or when a print fails/pauses with "no source" / 0x03008015 / 0x0500C010, keeps stopping at layer 0, "isn't pulling filament", or they ask which AMS slot / use_ams / ams_map to print with. It maps the print to the source that actually holds the filament the slice needs (an AMS slot or the external spool), because the

Slice a 3D model (STL/STEP/3MF) into a print-ready .gcode.3mf for the Bambu Lab A1 mini, and optionally upload + start the print. ALWAYS use this for any A1-mini slicing — driving OrcaSlicer's CLI directly silently produces WRONG output (it ignores Bambu's profile inheritance and reverts layer height/speeds/temps to defaults), and this skill flattens the profiles and verifies the result. Triggers on natural asks like "slice this for my A1", "get this STL ready to print", "make cube.stl printable on the a1", "print the benchy at 0.12mm on my a1 mini", or "I exported this from Fusion, need it on the bambu a1 mini in matte PLA" — including a freshly downloaded/exported STL or STEP, and choosing a layer height (0.08–0.28mm), nozzle, or filament; no slicer need be named. Do NOT use it when nothing needs slicing: controlling a live print (pause/resume/stop), calibration/bed-leveling, jogging axes, dashboard previews/thumbnails, or sending an already-sliced .gcode.3mf to the printer.

Apply Color Universal Design (CUD) so colors work for everyone, including color-vision deficiency (~1 in 20 men; red-green is by far the most common). ALWAYS use this when choosing, designing, or reviewing colors in any UI, dashboard, chart, map, or visualization — especially where color carries meaning (status / error / success / warning, categories, severity, on/off). It gives a colorblind-safe palette (with hex), the WCAG contrast rules, and an audit checklist. Triggers on asks like "is this colorblind-safe?", "pick an accessible color palette", "review these status colors", "make this chart readable", "color universal design / CUD / カラーユニバーサルデザイン", "色覚", or picking accent/status colors even when accessibility isn't named. Do NOT use for non-color styling alone (layout, spacing, typography) or when no color conveys meaning.

Run an external AI code review to get independent feedback on code changes. Use this skill when the user asks for a code review, says "コードレビューして", "レビュー", "変更を見て", "code review", or wants external feedback on their recent commits or uncommitted changes.

A knowledgeable neighbor who offers a fresh perspective on architecture, design decisions, and test strategy. Use proactively when a second opinion would improve quality, or when the user says "別の視点が欲しい", "設計を相談したい", "相談", "smart-friend に聞いて", or asks for feedback on their approach.

オシロスコープで2つの信号のあいだのエッジ時間差(位相/オフセット/スキュー/遅延)を測る、その時間差の ジッタやドリフトを見る、1PPS どうしの整合を測る、Rigol を SCPI(LAN)でスクリプト計測する、波形を吸い 出してエッジ時刻の差を出す、ときは必ずこの skill を参照する。「CH1 と CH2 のエッジ差」「2つのパルスが どれだけずれてる」「PPS の位相/整合」「立ち上がりの時間差/遅延/スキュー」「規律出力 vs 基準のずれを ベンチで実測」「オシロ計測の python」「(2信号の時間差計測で)トリガがかからない/プローブが原因か」 「オシロで測った時間差は本物か」の文脈なら、明示的に "oscilloscope" と言わなくても発火する。自力で 答えられそうでも参照すること: 素の知識では誤りやすいハード固有の罠(内蔵 delay/RDELay は幅の広いパルスで エッジをペアにできず失敗、×1/×10 プローブのスキューが固定オフセット、単発値はドリフトの1点)と実証済み ヘルパ scripts/rigol_scpi.py を含むため。発火しない(対象外。いずれも「2信号のエッジ時間差」ではない): 単一信号の周波数・デューティ・電圧・波形をオシロで見るだけ、ロジックアナライザやプロトコル(SPI 等)の デコード、ファンクションジェネレータでの波形出力、スペアナ、TDC/周波数カウンタ、アイダイアグラム、 phase noise や Allan 偏差などの周波数安定度解析、回路シミュレーション。

Git worktree workflow for parallel development. Start new features or bug fixes in isolated worktrees, enabling multiple Claude sessions to run simultaneously. Use when: starting new feature development, needing parallel work, or managing worktree creation/listing/completion.

Consult OpenAI Codex as a trusted friend for design review, architecture feedback, or technical advice. Use when the user asks to consult Codex or wants a second opinion.