`srb ephemeris` — Real Sun/Planet Geometry (Optional Feature)

Usage

srb ephemeris <action> [options]

Install srb[spice] for live queries. Help and completion need neither the extra nor Isaac Sim; download/info load spiceypy and numpy; import needs no spiceypy (details).

Actions

Action	Purpose
`download`	Fetches ~43 MB of pinned kernels (bundle).
`info`	Prints body azimuth, elevation, distance, angular diameter, and irradiance scale.
`import`	Imports illumination as an `srb_illum/2` sidecar (Lunarlab/PGDA details).

`info` Options

Option	Required	Description
`--body {moon,mars,earth}`	Yes	Observer.
`--lat LAT`	Yes	Latitude, `[-90, 90]`°.
`--lon LON`	Yes	Longitude, °.
`--alt ALT`	No (default `0.0`)	Height above mean radius, m.
`--utc UTC`	Yes	ISO-8601 epoch; `de440s`: 1850–2149.
`--bodies BODIES`	No (default `sun,earth`)	Choices: `sun,earth,moon,mars,venus`; Sun included; no duplicates/unknowns.

`import` Options

Option	Required	Description
`--source {lunarlab-zarr,lunarlab-npz,pgda-lpsr}`	Yes	Format.
`--input PATH`	Yes	Source.
`--baked-dir PATH`	No	Target baked patch.
`--out PATH`	Yes*	Output.
`--crs CRS`	Yes*	Target CRS.
`--center-xy CX,CY`	Yes*	Center.
`--size-m SIZE`	Yes*	Patch size.
`--lat LAT` / `--lon LON`	Yes*	Site coordinates.
`--gsd-m GSD`	Yes*	Grid spacing.
`--epoch-range T0,T1`	No	UTC range.
`--epoch-stride N`	No (default `1`)	Epoch sampling interval.
`--body {moon,mars,earth}`	No (default `moon`)	Terrain body; PGDA-LPSR supports Moon only.

Without --baked-dir, starred options are required. Baked metadata supplies CRS, patch size, site, and default output. Grid spacing uses source resolution unless --gsd-m overrides it; --out overrides the output path. Do not pass --lat/--lon with it (status 2). See importer rules.

Examples

srb ephemeris download

Shackleton:

srb ephemeris info --body moon --lat -89.66 --lon 0.0 \
  --utc 2026-11-01T12:00:00 --bodies sun,earth

sun: az=279.043° el=1.512° dist=149685302 km diam=0.559°
earth: az=64.201° el=2.551° dist=384412 km diam=1.916°
irradiance_scale=1.0021

Apollo 17:

srb ephemeris info --body moon --lat 20.19 --lon 30.77 \
  --utc 1972-12-11T19:54:57 --bodies sun

Jezero:

srb ephemeris info --body mars --lat 18.44 --lon 77.45 \
  --utc 2021-02-18T20:55:00 --bodies sun

Lunarlab:

srb ephemeris import --source lunarlab-zarr \
  --input /data/lunarlab/<product>/epochs.zarr \
  --baked-dir <terrain-cache>/moon/<site>/<patch-key>

PGDA-69 LPSR:

srb ephemeris import --source pgda-lpsr \
  --input /data/pgda/lpsr_shackleton.tif \
  --crs "IAU_2015:30135" --center-xy 0.0,10309.969398639505 \
  --size-m 4000 --gsd-m 5.0 --lat -89.66 --lon 0.0 \
  --out /tmp/shackleton_illumination.npz

Disabling Auto-Fetch

Queries fetch missing kernels by default. Disable fetch to require pre-fetch:

export SRB_EPHEMERIS_AUTO_FETCH=0
srb ephemeris download   # run once, ahead of time, with network access

Missing kernels then raise KernelsMissingError naming srb ephemeris download.

Space Robotics Bench