japan-geoid

A library for calculating geoid heights in Japan using GSI's geoid model. It is implemented in Rust and additionally supports Python and JavaScript.

日本のジオイド高を計算するためライブラリです。Rust で実装されており、Python と JavaScript (Wasm) でも利用できます。国土地理院のジオイドモデルを用いて、国土地理院による C++ のサンプルコードに準拠した補間計算を行います。

Supported Models

測量法に基づく国土地理院長承認（使用）R 5JHs 560

License: MIT

本ライブラリは、国土地理院が提供するものではありません。

Python

Installation

pip install japan-geoid -U

Usage

from japan_geoid import (
    load_embedded_gsigeo2011,
    load_embedded_jpgeo2024,
    load_embedded_jpgeo2024_hrefconv2024,
)

# Load the embedded geoid model.
geoid = load_embedded_jpgeo2024_hrefconv2024()

# Calculate the geoid height.
(lng, lat) = (138.2839817085188, 37.12378643088312)
height = geoid.get_height(lng, lat)
print(f"{lng=} {lat=} {height=}")

# Returns NaN if the input is outside the domain.
geoid.get_height(10.0, 10.0) # => nan

# The library also works with Numpy.
import numpy as np
geoid.get_heights(
    np.array([138.2839817085188, 141.36199967724426]),
    np.array([37.12378643088312, 43.06539278249951]),
)

Rust

Installation

cargo add japan-geoid -F jpgeo2024_hrefconv2024

Usage

use japan_geoid::gsi::load_embedded_jpgeo2024_hrefconv2024;
use japan_geoid::Geoid;

fn main() {
    // Load the embedded geoid model.
    let geoid = load_embedded_jpgeo2024_hrefconv2024();

    // Calculate the geoid height.
    let (lng, lat) = (138.2839817085188, 37.12378643088312);
    let height = geoid.get_height(lng, lat);
    println!("Input: (lng: {lng}, lat: {lat}) -> Geoid height: {height}");

    // Returns NaN if the input is outside the domain.
    assert!(f64::is_nan(geoid.get_height(10.0, 10.0)))
}

JavaScript (Wasm) - Experimental

Installation

npm install japan-geoid

Usage

import init, {
  loadEmbeddedGSIGEO2011,
  loadEmbeddedJPGEO2024,
  loadEmbeddedJPGEO2024Hrefconv2024,
} from "japan-geoid";

await init(); // load .wasm

const geoid = loadEmbeddedJPGEO2024Hrefconv2024();

console.log(
  geoid.getHeight(138.2839817085188, 37.12378643088312)
); // => 39.56593692999162

console.log(
  geoid.getHeights(
    new Float64Array([138.2839817085188, 141.36199967724426]),
    new Float64Array([37.12378643088312, 43.06539278249951])
  )
); // => Float64Array(2) [ 39.56593692999162, 31.98825817633539 ]

Build

wasm-pack build -t web

License

MIT License

Authors

• Taku Fukada (@ciscorn) - 測量法に基づく国土地理院長承認（使用）R 5JHs 560
• @rot1204
• and all contributors!