Standards Development

Scope

This document specifies the Lunar Planar Coordinate System, which defines a two-dimensional, conformally projected grid onto a plane, for the purposes of mapping and positioning of the control point on the lunar surface.Standardization to ensure safe, accurate, and efficient operations on the lunar surface

Purpose

In the 2020s, human activities related to the development of the Moon have intensified, and the development of the LunaNet standard by space agencies is underway. While complying with the LunaNet standard, downstream industrial users further require a lunar planar coordinate system based on World Trade Organization (WTO) agreements, such as ISO standards, for applications including terrestrial navigation, construction, and surveying. To address this issue, this document describes fundamental information on lunar planar coordinate systems and the rules for their specification. This standardization will be carried out in coordination and cooperation with the United Nations ICG Working Group L for Lunar PNT and Joint ICG-IOAG Multilateral Cislunar PNT Workshop.

For downstream space services and space-based applications on the lunar surface, a lunar planar coordinate system is indispensable. Without a defined coordinate system, activities such as positioning and navigation cannot be initiated. In order to advance standardization related to the Moon, it is necessary to begin by specifying a lunar planar coordinate system.

The Geocentric Coordinate System and Latitude and Longitude coordinate system has already been determined, but It is difficult to say that a common planar coordinate system for the Moon is widely established. The Geocentric Coordinate System is difficult to use. This is because the axis of rotation of the moon is the Z axis, which is different from the vertical direction on site and is difficult to understand intuitively. And the latitude and longitude coordinate system is difficult to use. Because its units are angles. It is more efficient to carry out building and facility layout and infrastructure maintenance on the moon in metric. therefore, construction is required in metric.

Problems when projecting the spherical surface onto the plane.

The Moon may be regarded as an ellipsoid in a broad sense and, therefore. The lunar surface is curving surface. When a figure on a spherical surface is projected onto the plane, the angles, the distances, the area cannot be projected correctly. Because Euclidean geometry does not hold.

The need for a planar coordinate system

When developing infrastructure on the moon, it is planned and designed on a flat surface using CAD. In cases such as complex plant construction, high accurate layout shall be required. Construction is difficult in latitude and longitude. In other word, the coordinate system based on metric system is required. Therefore, a lunar plane coordinate system should be established.

Some are cautious about creating such a standard. But there is an urgency to establish correct positions on a plane coordinate system. When experts work to survey, survey on the moon, build facilities and develop infrastructure on the Moon, they need a plane coordinate system to ensure construction accuracy, safety and security. This document has been carefully crafted to respect the future work of expertized lunar researcher.