---
title: "Mars Coordinate System: A Comprehensive Guide to China's Mapping Coordinates"
date: 2023-08-02T13:46:22.000Z
author: Z.SHINCHVEN
tags: [Mars Coordinate System, 火星坐标系]
canonical: https://atlassc.net/2023/08/03/mars-coord
---
China's map coordinate systems can be somewhat complex. Different map service providers use different coordinate standards, posing some challenges for developers. In this blog, we will delve into China's coordinate standards, explain the standards used by each mainstream map service, and introduce how to effortlessly convert coordinates using the [mars-coord](https://github.com/ShinChven/mars-coord) library.

## Complexity of China's Coordinate Standards

The complexity of China's coordinate systems primarily stems from different map service providers using different coordinate standards. For example, Baidu Maps uses the BD-09 standard, while Amap and Tencent Maps use the GCJ-02 standard. The international standard WGS84 has some offsets within mainland China.

## mars-coord: A One-Stop Coordinate Conversion Library

[mars-coord](https://github.com/ShinChven/mars-coord) is a library for converting Mars coordinate systems, written by me. Using this library, you can effortlessly transition between various coordinate standards.

Below is an overview table of the main coordinate standards and type keys in China:

| Type Key | Coordinate Standard | Applicable Map Services                                  |
| -------- | ------------------- | -------------------------------------------------------- |
| WGS84    | WGS84               | International Standard                                   |
| GCJ02    | GCJ-02              | Amap, Tencent Maps, Apple Maps(China), Google Maps(China) |
| AMAP     | GCJ-02              | Amap                                                     |
| QQ       | GCJ-02              | Tencent Maps                                             |
| BD09     | BD-09               | Baidu Maps                                               |
| BAIDU    | BD-09               | Baidu Maps                                               |
| CGCS2000 | CGCS2000            | China Geodetic                                           |

Installation is quite simple:

```bash
npm install mars-coord
```

Conversion example code:

```typescript
import { Coordinate, convertCoordinate } from 'mars-coord';
const myCoordinate: Coordinate = [110.030774, 36.815854];
const result = convertCoordinate(myCoordinate, 'WGS84');
```

## Conclusion

The Mars coordinate system is a complex yet vital subject in Chinese map development. The `mars-coord` library aims to simplify the process of coordinate conversion, helping developers focus on building excellent map applications.

Whether you are a map application developer or an enthusiast interested in coordinate studies, the `mars-coord` library is worth a try.