README.MD

lks base knowledge for Sweden
=============================

This repository contains base knowledge data, covering Sweden, intended to be used as base knowledge for kDB. It can be installed as a ROS package, for use with ros_kdb, or without ROS.

Data
====

* `data/dems` digital elevation maps covering the south of Sweden, from NASA SRTM downloaded using [https://dwtkns.com/srtm30m/](dwtkns). The following tiles are included:

![Selected area in dwtkns](doc/dwtkns_area.png)

ROS
===

Add this package to your ROS workspace:

```bash
git clone https://gitlab.liu.se/lks/base_knowledge/lks_base_knowledge_sweden.git
```

It is recommended that you use `--symlink-install` with `colcon` to avoid duplicating the data between source and install.

You can access the data in the install prefix, for instance, with:

```bash
cd `ros2 pkg prefix lks_base_knowledge_sweden`
```

ros_kdb
=======

The following service call can be used to load the data in a `ros_kdb` server:

```bash
# Start kDB Server:

ros2 run ros_kdb

# Load the data

ros2 service call /kdb_server/sqm_query ros_kdb_interfaces/srv/QueryDatabase "queries: [{query: 'REGISTER BASE KNOWLEDGE directory: \"`ros2 pkg prefix lks_base_knowledge_sweden`/share/lks_base_knowledge_sweden/data/dems/\"'}]"
```

Example of queries:

```bash
ros2 service call /kdb_server/get_altitude ros_kdb_interfaces/srv/GetAltitude "{latitude: 58.393166, longitude: 15.571833, srid: 4326}"
```

License
=======

The data contained in this repository is either in the public domain or can be distributed without restrictions.

Further information can be found:
* [https://www.usgs.gov/centers/eros/data-citation](U.S. Geographical Survey): for the SRTM DEM