Middle Darling DEM 2014.

This is part of the project Aqcuisition of LiDAR, Imagery and Derived Products for Areas of the Murray-Darling Basin as described in the Statement of Requirement RFTGA2013/2284 (GEMDOGRE-834). The Middle Darling area is located in New South Wales and stretches from Bourke in the North-East to Wilcannia to the South-West. A bare-earth DEM (Digital Elveation Model) grid is created from class 2 (ground) using a point to TIN and TIN to raster process, with a cell spacing of 1m x 1m. Heights in the DEM are orthometric heights. Areas outside the project boundary have been coded using a NODATA value. For the DEM generation hydro flattening is applied as described in chapter 11. The format of the DEM tiles is 32 bit floating point Esri GRID.

Aerial imagery has been collected coincident with the LiDAR data as three band RGB data. The resolution of the images is 20cm. The tiles have been delivered in GeoTiff format with tfw files. As the AOI is too large to create a single ECW mosaic, the mosaic has been delivered as a Esri Mosaic Dataset (geodatabase format containing a catalogue of the tiles).

At the time of ground survey and aerial survey the area was experiencing severe drought conditions.. A large area of the grassland areas ground cover was sparse making very difficult to make an accurate identification between the two types . The adopted landcover types are

1. Bare Earth

2. Scattered Trees

3. Chenopod Shrubs (Salt Bush)

4. Scrub

5. Hummock Grasses

6. Hummock and Tussock Grasses

For the generation of the bare-earth DEM hydro-flattening was required for water bodies with a surface area greater than 625m2 and for any visible water in any part of a connected river network or recognised waterway (regardless of size). To achieve the realistic interpolation of the DEM, Aerodata has included breaklines in the DEM. The breaklines have been mapped manually from imagery and LiDAR data such that at each bank the water level is at equal height with a gradient following the immediate terrain. In this process, special attention is given to discontinuities along watercourses resulting from varying water levels during the acquisition phase.

Middle Darling DEM 2014.

This is part of the project Aqcuisition of LiDAR, Imagery and Derived Products for Areas of the Murray-Darling Basin as described in the Statement of Requirement RFTGA2013/2284 (GEMDOGRE-834). The Middle Darling area is located in New South Wales and stretches from Bourke in the North-East to Wilcannia to the South-West. A bare-earth DEM (Digital Elveation Model) grid is created from class 2 (ground) using a point to TIN and TIN to raster process, with a cell spacing of 1m x 1m. Heights in the DEM are orthometric heights. Areas outside the project boundary have been coded using a NODATA value. For the DEM generation hydro flattening is applied as described in chapter 11. The format of the DEM tiles is 32 bit floating point Esri GRID.

Aerial imagery has been collected coincident with the LiDAR data as three band RGB data. The resolution of the images is 20cm. The tiles have been delivered in GeoTiff format with tfw files. As the AOI is too large to create a single ECW mosaic, the mosaic has been delivered as a Esri Mosaic Dataset (geodatabase format containing a catalogue of the tiles).

At the time of ground survey and aerial survey the area was experiencing severe drought conditions.. A large area of the grassland areas ground cover was sparse making very difficult to make an accurate identification between the two types . The adopted landcover types are

1. Bare Earth

2. Scattered Trees

3. Chenopod Shrubs (Salt Bush)

4. Scrub

5. Hummock Grasses

6. Hummock and Tussock Grasses

For the generation of the bare-earth DEM hydro-flattening was required for water bodies with a surface area greater than 625m2 and for any visible water in any part of a connected river network or recognised waterway (regardless of size). To achieve the realistic interpolation of the DEM, Aerodata has included breaklines in the DEM. The breaklines have been mapped manually from imagery and LiDAR data such that at each bank the water level is at equal height with a gradient following the immediate terrain. In this process, special attention is given to discontinuities along watercourses resulting from varying water levels during the acquisition phase.