July 2002 Natural Resources Canada National Landsat 7 Orthoimage project

Presentation plan National Canadian orthoimage Background Benefits for Canadian Sources of control 2002 production status Approach Quality control process Accuracy Outputs Products with David

Background Imagery is one of the nodes for the Geoconnections framework Landsat-7 had a 15 metres resolution, no copyright for distribution, low cost Provinces and federal agencies interested in the product (cost sharing) Need of provincial vector data to control the image and to meet accuracy Many partners to this initiative (All Provinces and 3 territories and 14 federal agencies) Rapidity to produce a national coverage is critical (3 to 5 year program) Agreement signed by partners in 1999

Benefits for Canadian National coverage With best accuracy available -> improve national accuracy Vertical integration with provincial data Base for updating Entities used as control are kept future correction Possibilities of value added products Framework shared by many partners and users of geospatial data Free (if downloaded from Geoconnections discovery portal)

Sources of control GPS road network Provincial vector data Federal aerial triangulation NTDB 50K accurate (10 m) Less accurate vector data Federal or provincial DEMs

Aerial triangulation and provincal control distribution

Status

Approach Contracting-out time consuming work Establish control collection rules (specs) for more homogeneity Establish control collection criteria for more accuracy Develop a bonus/penalty approach to improve quality Automate what can be automated and reduce quality control cost Create the orthoimage with the selected control points with a unique commercial software

Sectors -Points / sectors- Overlapping-Zmin, Zmax

Examples of valid features

Lake selection criteria (roundness and minimum size) 2*Sqrt(Area*Pi)/perimeter > = 0.6

Quality control process

Accuracy of orthoimages Based on control accuracy, RMS of SRIT model and impact in X and Y of DEMBased on control accuracy, RMS of SRIT model and impact in X and Y of DEM

Outputs Orthoimages LCC, UTM for all Canada Control point and image point kept in DB for future correction needs Orthoimages free on CEONET Orthoimage 50K RGB available for free on the NET (Toporama) NTS 50K quads (CANIMAGE)

New Products from Orthoimages Ortho-image Landsat 7 Product CanImage CanImage ( ) CanImage GeoTIFF files can be opened in different applications in response to specific needs. Offers much flexibility Orthoimages on Toporama ( A Toporama orthoimage is a free low-resolution raster representation of the CanImage product.

CanImage (Product Search) 031G15

CanImage (Options)

CanImage (Shopping cart) View Result

Toporama Toporama, in existence since 1999 Is an Internet window that displays different types of topographic information (products) available from CTIS as images CanImage on Toporama NTDB on Toporama 031G08

For more information Toporama at CanImage at

Differences between Toporama and CanImage Orthoimages Produit généré à la demande du client non- emmagasiné sur un disque Produit préfabriqué emmagasiné sur un disque Low cost (25$)Free Downloadable, ready-to-use productAllows navigation on the Web site Full-resolution image (pixel size = 15 m)Image resolution varies depending on data-set latitude Images in the UTM projection or geographic coordinates (lat/long) Images with geographic coordinates (latitude/longitude) Images can be enhanced (linear or adaptative enhancement) or not Linear enhanced images Customer selects the 3 bands combinationPredefined combination of Landsat 7 bands 3, 2, and 1 Georeferenced imageNo georeferencing included in the GIF format GeoTIFF format supporting more than 16 million colors GIF format supporting only 256 colors; loss of detail CANIMAGETOPORAMA

Produit ortho-image Landsat 7 CanImage Questions ???