Grand River watershed orthoimagery 2000

Description

This digital orthomosaic covers the entire Grand River watershed. The watershed extends from the headwaters of the Grand River near Luther Marsh Reservoir to the mouth of the Grand River at Port Maitland on Lake Erie. Aerial photography was flown between April 4th-30th, 2000, and was provided to the Library by the Grand River Conservation Authority (GRCA) in September 2004. The pixel resolution of the orthomosaic is 30 cm.

Spatial reference and data type

This orthomosaic, because of its large file size is divided into two halves, a north and a south half, with the line of division passing through the City of Waterloo, and more specifically, through the University of Waterloo south campus. These georeferenced mosaics are available in Universal Transverse Mercator (UTM) coordinates; horizontal datum is North American Datum (NAD) 83. They are stored as compressed MrSID data files, with accompanying Sid World (SDW) files. The mosaics are approximately 2 GB each.

Data access

In order to access this electronic resource, please visit the Gospatial Centre reference desk during reference hours. Library reference staff are available to provide further information about this data set and to deliver data upon request.

Data manipulation

There are public workstations in the Geospatial Centre that provide access to both ArcGIS and ArcView software programs, program extensions and data manipulation utilities. Patrons may use the Geographic Information System (GIS) and image processing software in the library to view and manipulate the data. UWaterloo faculty, students and staff may copy these data to other media (for example: CD, DVD or Zip disc) for use elsewhere.

Data output

Given the large size of each of these mosaics, it is not practical nor is it useful to export the entire image unless at very low resolution. ArcGIS may be used to export small sections of the mosaic in a choice of bitmapped formats (also known as raster graphics) including JPG, TIFF, GIF, and BMP or in a choice of vector graphics formats including Adobe Illustrator (AI), Encapsulated Postscript (EPS), and Scalable Vector Graphics (SVG). Yet another option is PDF. The MrSID Geoviewer may also be used to export a small selection of the mosaic as either a TIFF or GeoTIFF image. The user defines the output resolution.

Use restrictions/licensing/copyright

These data are provided for personal use for academic, research, and/or teaching purposes. A data release agreement must be agreed to before these licensed data can be released. The Grand River Conservation Authority (GRCA) must be acknowledged on any derivative product, whether printed or electronic, including for example, a printed map, a raster or vector graphic, a web-based application, etc. Patrons are advised to fully respect the provisions of Canada's Copyright Act as well as terms and conditions imposed by the data provider.