Orthophotography within the Canterbury Region captured in 2021. Coverage encompasses the Mackenzie basin, being parts of the Mackenzie District, and upper parts of Waitaki District.
Imagery was captured for Environment Canterbury by Landpro Ltd, 13 Pinot Noir Drive, Cromwell 9310, New Zealand.
Data comprises: • 823 ortho-rectified RGB GeoTIFF images in NZTM projection, tiled into the LINZ Standard 1:5000 tile layout • Tile layout in NZTM projection containing relevant information.
The supplied imagery is in terms of New Zealand Transverse Mercator (NZTM) map projection. Please refer to the tile index layer for specific details, naming conventions, etc.
Imagery supplied as 30cm pixel resolution (0.3m GSD), 3-band (RGB) GeoTIFF. The final spatial accuracy is ±2m at 90% confidence level in clear flat areas for tiles in the area of interest of the survey.
This dataset includes some image tiles labelled as peripheral by the supplier, being imagery captured which was outside the area of interest of the survey. These peripheral tiles may contain artefacts from orthrectifcation, do not have a stated spatial accuracy, and may not be suitable for all purposes. See the index tile layer for details of which tiles are labelled as peripheral.
Index tiles for this dataset are available as layer [Canterbury - Mackenzie 0.3m Rural Aerial Photos Index Tiles (2021)](http://data.linz.govt.nz/layer/106767)
Camera: Imagery for this schedule was acquired using the Leica ADS100 line scanning camera with SH100 sensor head. The camera was fitted to a Leica PAV100 HP high performance gyro-stabilised mount.
Flight Planning: Careful consideration was given during flight planning to geographic location, terrain, topographical characteristics of the area, acquisition efficiency, final output resolution and meeting the various requested orthophoto quality specifications.
Environmental Specification: All imagery was captured without the presence of cloud or cloud shadow within the specified areas of interest. Rivers were captured during times of appropriate flow/stage height/rainfall restrictions as specified by the client. These criteria were set to avoid periods of high river flow (flooding), rather than to target abnormally low river flows.
Ground Control: A total of 101 new ground control points were observed within this area, of these 23 were selected and used with the aerial triangulation and final bundle adjustment. Data from Global Survey’s and LINZ CORS sites, along with several existing LINZ benchmarks, were used in Leica Infinity software to process and check the ground control.
Map Projection and Datum: All spatial data for this project is supplied in the New Zealand Transverse Mercator (NZTM2000) projection in terms of the New Zealand Geodetic Datum 2000 (NZGD2000).
Image Processing: Hexagon Geosystems Services India carryied out Orthophoto production. Leica Xpro software along with the QS2 distributed processing environment and inbuilt Hexagon Image Manager and Quality Manager2 were used during relevant phases of production.
Aerial Triangulation (AT): No abnormalities or complications were encountered during this phase. All aerial triangulations are carried out to ensure accuracies in the region of 1xGSD value. This was achieved with adjusted RMS position residuals less than 30cm, ensuring excellent overall quality and spatial accuracy.
Orthophoto production: Individual radiometric profiles were created and checked for each strip ensuring optimal results across the final ortho-mosaic. No complications were encountered during orthophoto generation, mosaicking and tiling. Various quality checks including accuracy, colour, contrast, sharpness, seamline positioning, refraction and generation artifacts were performed and found satisfactory on the final orthophoto tiles.
Peripheral Imagery: The full extent of all captured imagery outside of the tiles covering the area of interest has been delivered. This imagery has been orthorectified with the same DEM used to generate the primary AOI orthophotos. As such, these DEMs may not cover the entire area of peripheral imagery and associated artefacts may be present.