geographic_info: geodesy | geographic_msgs

Package Summary

ROS messages for Geographic Information Systems.

• Author: Jack O'Quin
• License: BSD
• Repository: geographic_info
• Source: git https://kforge.ros.org/geographicinfo/geographic_info

Geographic information messages.

ROS Message and Service Types

Unique Identifiers

Map points, features and segments all have universally unique identifier names (UUID), using geographic_msgs/UniqueID messages.

Each UUID is stored as a human-readable string of hexadecimal digits and dashes in "01234567-89ab-cdef-0123-456789abcdef" format. UUID generation is up to the programmer, but the intent is for matching features within a domain such as Open Street Map to yield the same UUID. The recommended method is RFC 4122 variant 5, computing the SHA-1 hash of a URL encoded using the map source.

For example, the Open Street Map URL scheme is:

• http://openstreetmap.org/node/999999

• http://openstreetmap.org/way/999999

• http://openstreetmap.org/relation/999999

Here, 999999 is the decimal representation of the integer OSM node, way, or relation ID without leading zeros.

Other map sources should use similar conventions.

Cartography

The geographic_msgs/GetGeographicMap service takes a map URL and optional geographic_msgs/BoundingBox, returning a geographic_msgs/GeographicMap,

The map contains a geographic_msgs/WayPoint vector and a geographic_msgs/MapFeature vector. Each point or feature is identified by a geographic_msgs/UniqueID, and optional geographic_msgs/KeyValue properties describing their roles.

Features represent any interesting collection of map points: hiking trails, bicycle paths, streets, highways, tunnels, bridges, rivers, buildings, property boundaries, etc. They contain a sequence of component unique identifiers, which may name points or other features. A feature may not directly or indirectly contain itself, so its subordinate points and features must form a tree structure. But, a feature may belong to more than one higher-level feature.

Route Network

Not all way points in a map are drivable by any particular vehicle. Some delimit buildings, rivers, or property boundaries. The geographic_msgs/RouteNetwork message represents drivable paths as a directed graph using a geographic_msgs/WayPoint vector and a geographic_msgs/RouteSegment vector. Each segment represents an edge from one point to another. Unless the path is one-way, another segment will point in the opposite direction.