Elevation data is a fundamental data theme that has been provided by Natural Resources Canada (NRCan) to Canadians as essential geographic information.  The renewal and enhancement of national elevation data coverage has recently been identified as a priority for Canada’s SDI.  LiDAR data provide new opportunities for enhancing elevation information, products and services.  The elevation project team at CCMEO (Canada Center for Mapping and Earth Observation), Natural Resources Canada (NRCAN) has created a strategy to increase high-resolution elevation data coverage in the country by optimizing past and future investments in elevation data acquisition. The strategy also aims to improve accessibility to these data.

The acquisition strategy is composed of two mains components:

1)            In the North (North of the productive forest line) NRCan is collaborating with the United States. The project aims to create in the public domain a 2m resolution elevation surface model for the whole Arctic in 2017. The elevation is derived from high resolution satellite imagery.

2)            In the South part of the country (South of the productive forest line) more accurate elevation data such as Lidar are needed for forest inventory, flood plain mapping, agriculture, infrastructure etc. To acquire this Lidar data, the federal government is working with provinces and territories to free-up existing data and participate in new acquisitions.

As part of this strategy, NRCan are also working on the following subjects:

• Development of a system  for the management and dissemination of elevation data (including Lidar data) and elevation derivative products;
• Development of a national Lidar data acquisition guideline
• Development of a national elevation data inventory management system.
• Extraction of cartographic features (others than elevation) from Lidar data

In order to implement the strategy, CCMEO is acquiring a large inventory of Airborne Laser Data (LiDAR). These data are particularly massive and their management and processing require enormous computing capacity. CCCMEO experts are developing innovative approaches to address the problems of managing, processing and disseminating elevation big data. To achieve this, the team will use a data structure GeoHashTree (see http://publications.gc.ca/collections/collection_2015/rncan-nrcan/M103-1-4-2014-eng.pdf). In addition, to facilitating the management of point clouds this structure reduces data storage space considerably, while also facilitating data access and handling.

For the short term, DEMs and derivative products at 2m resolution (GEOTIFF) will be disseminated publically. We want to also create a mosaic including multi-resolution(resolution between 5m to 300m) DEMs for web services (WMS,WCS,…).