jgdtrans for TypeScript/JavaScript

Unofficial coordinate transformer by Gridded Correction Parameter which Geospatial Information Authority of Japan (GIAJ, formerly GSIJ) distributing for TypeScript/JavaScript.

国土地理院が公開しているパラメータファイル（par ファイル）による座標変換（順逆変換）の非公式な実装です。

Features:

• Supports offline transformation (no web API)
  • オフライン変換（web API 不使用）
• Supports both original forward and backward transformation
  • 順変換と逆変換の両方をサポート
• Supports verified backward transformation
  • 精度を保証した逆変換のサポート
• Supports all TKY2JGD, PatchJGD, PatchJGD(H), HyokoRev, SemiDynaEXE and POS2JGD (geonetF3 and ITRF2014)
  • For example, Tokyo Datum to JGD2000 (EPSG:4301 to EPSG:4612) and JGD2000 to JGD2011 (EPSG:4612 to EPSG:6668)
  • 上記の全てをサポート
• Clean implementation
  • 保守が容易な実装

Usage

This package does not contain parameter files, download it from GIAJ.

このパッケージはパラメータファイルを提供しません。公式サイトよりダウンロードしてください。

It supports ESM and non-ESM loading:

<!-- ESM -->
<script type="module" type="text/javascript">
  import jgdtrans from 'https://cdn.jsdelivr.net/npm/@paqira/[email protected]/dist/jgdtrans.js';
  ...
</script>
<!-- non-ESM -->
<script
  nomodule
  defer
  src="https://cdn.jsdelivr.net/npm/@paqira/[email protected]/dist/jgdtrans.nomodule.min.js"
  integrity="sha256-StpZg/zmEw183fm6Dcx9ifllTnf8bwdeJWAqz+heTtU="
  crossorigin="anonymous"
></script>

Sample code:

// Comment out following `import ...;` when loading jgdtrans.nomodule{.min}.js
import jgdtrans from "https://cdn.jsdelivr.net/npm/@paqira/[email protected]/dist/jgdtrans.js";

// Contents of SemiDyna2023.par
const contents = "...";
const tf = jgdtrans.Transformer.fromString(contents, "SemiDynaEXE");

// Geospatial Information Authority of Japan
const origin = new jgdtrans.Point(36.10377479, 140.087855041, 2.34);

// forward transformation
const result = tf.forward(origin);
// prints Point(latitude=36.103773017086695, longitude=140.08785924333452, altitude=2.4363138578103)
console.log(result.toString());

// backward transformation
const p = tf.backward(result);
// prints Point(latitude=36.10377479, longitude=140.087855041, altitude=2.34)
console.log(p.toString());

// backward transformation compatible to GIAJ web app/APIs
const q = tf.backwardCompat(result);
// prints Point(latitude=36.10377479000002, longitude=140.087855041, altitude=2.339999999578243)
console.log(q.toString());

Licence

MIT

Reference

1. Geospatial Information Authority of Japan (GIAJ, 国土地理院): https://www.gsi.go.jp/, (English) https://www.gsi.go.jp/ENGLISH/.
2. TKY2JGD for Windows Ver.1.3.79 (reference implementation): https://www.gsi.go.jp/sokuchikijun/tky2jgd_download.html released under 国土地理院コンテンツ利用規約 which compatible to CC BY 4.0.
3. Other implementation: Rust https://github.com/paqira/jgdtrans-rs, Python https://github.com/paqira/jgdtrans-py, Java https://github.com/paqira/jgdtrans-java.