SPICEBodies.jl

Interact with SPICE kernels without learning the SPICE interface in-full!

Installation

Choose one of the following!

pkg> add SPICEBodies

import Pkg
Pkg.add("SPICEBodies")

Usage

This package requires SPICE.jl; SPICEKernels.jl. Once you load your desired SPICE kernels, you could interact with each kernel object (satellite, planet, barycenter, lagrange point, etc.) using the SPICE interface. In fact, if you want to do anything more complicated than retrieve some physical parameters, and request Cartesian-state ephemeris data, you probably should use the SPICE toolkit! If, however, your desired usage falls within the narrow limitations mentioned above, SPICEBodies.jl could help you to concisely retrieve solar system ephemeris data.

First, load your desired SPICE kernels using SPICE.jl. SPICEKernels.jl provides an easy Julian interface for downloading (and caching) NASA's publicly available Generic Kernels. All generic kernels are available as callable structs within SPICEKernels.jl. If you'd like to know what each kernel does, check the Extended Help in each kernel's docstring.

julia> using SPICE: furnsh

julia> using SPICEKernels

julia> furnsh(
           de440(),                    # position and velocity data for major solar system bodies
           latest_leapseconds_lsk(),   # timekeeping
           gm_de440(),                 # mass parameters for major solar system bodies
           pck00011(),                 # physical properties of major solar system bodies
       )

Now you're ready to use SPICEBodies.jl. To retrieve position and velocity data, you must construct a KernelBody instance, or implement the AbstractKernelBody interface yourself! To retrieve physical characteristics, or NAIF ID codes, you can provide AbstractKernelBody instances, or the body's name.

julia> using AstroTime, SPICEBodies

julia> earth = KernelBody("earth")
KernelBody(399)

julia> moon = KernelBody("moon")
KernelBody(301)

julia> x, y, z, ẋ, ẏ, ż = earth(AstroTime.J2000_EPOCH, wrt=moon)
6-element Vector{Float64}:
 291608.38463343546
 266716.83339423337
  76102.48709990202
     -0.6435313877190327
      0.6660876840916304
      0.30132570498227307

julia> μ = gm("earth")
398600.4355070226

julia> R = radii(moon)
3-element Vector{Float64}:
 1737.4
 1737.4
 1737.4