sun_position — GEOCAM `sun` op

• Data kinds: signal → table

• Call: import fullseye as fs; fs.ledger.sun_position(lat_deg, lon_deg, unix_times) (to call the implementation directly, import geocam; geocam.sun_position(lat_deg, lon_deg, unix_times); from the registry, opsgeocam.get("sun_position"))

Usage

> This operator's description has not been translated yet. The original text follows as it is.

緯度・経度・時刻(UNIX 秒、UTC)→ 太陽の方位・仰角 [度] (NOAA の太陽位置アルゴリズム、Meeus 1998 の低精度式)。

公開された閉形式(NOAA Global Monitoring Laboratory の Solar Calculator と同じ式:

ユリウス世紀 → 平均黄経・平均近点角・中心差 → 視黄経 → 黄道傾斜 → 赤緯と均時差 →

時角 → 天頂角・方位角)。精度は 2000 年 ± 1 世紀で 0.01° 程度(NOAA の記述)、

大気屈折は仰角に足す(NOAA の区分式、水平近くで最大 0.57°)。時刻は UTC の UNIX 秒

(1-D、float でよい)。うるう秒・ΔT は無視する(0.01° に効かない)。

Args:

lat_deg, lon_deg: 観測点。経度は東が正。

unix_times: (N,) UNIX 秒(UTC)。スカラも可。

Returns:

table: `azimuth_deg (N,)(北 0°、時計回り)/ elevation_deg` (N,)(屈折込み)/

`elevation_true_deg (N,)(屈折なし)/ declination_deg / equation_of_time_min` /

`hour_angle_deg / n`。

真値で確かめてある性質(tests/test_geocam.py): 春分の正午に仰角 = 90 − |緯度|、

正午の方位は北半球で 180°(南)、方位は東 → 南 → 西と単調、日の出と日の入りの

仰角が対称、赤緯は ±23.44° に収まる。

Detailed usage guide

• geocam family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• poc_public_camera_heading — py -3.11 examples/poc_public_camera_heading.py

• poc_public_camera_heading_real — py -3.11 examples/poc_public_camera_heading_real.py

Ops the type connects to (they accept `table` as input)

render_skyline_view · camera_orientation_from_skyline

Same category (`sun`)

sun_pixel_position · camera_orientation_from_sun · sun_bloom_fit · camera_orientation_from_sun_candidates

*Provenance: geocam.py — GEOCAM operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

sun_position — GEOCAM sun op