Description:
Extracted from stereo aerial or satellite imagery, the DEMSA2 offers highly detailed (2 m resolution), accurate and cost-effective terrain data, available on demand. Available as both a digital surface model (DSM) and a digital terrain model (DTM), with a suite of options, your DEMSA2 order can be tailored to your needs.
Use-cases:
Accurate and detailed elevation data is critically important to inform decision-making in numerous areas, such as:
- construction (road and building construction),
- renewable energy (site selection, energy yield estimation),
- telecommunication (tower positioning),
- air traffic routing and navigation,
- agriculture (precision farming, vineyard establishment, irrigation scheme design, drainage system planning),
- forestry (harvest planning, timbre volume estimation),
- environmental management and impact assessments (visual impact assessment of wind turbines),
- disaster risk planning and management (flood modelling, mudslide and avalanche predictions),
- as well as urban and regional planning (densification monitoring, population estimations).
Derivatives:
Get more than your bargain for - the DEMSA2 can be used to generate numerous derived datasets that can offer valuable insights to your project.
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Slope
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Aspect
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Solar radiation
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Topographical wetness index (TWI)
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Product levels:
Purchase what you need - the DEMSA2 is offered at various product levels to allow customers to tweak their orders to their specific requirements. The levels are as follows:
- Level 1 (L1) - the DEMSA2 DSM straight off the assembly line, for when money and/or time is at a premium.
- Level 2 (L2) - the DEMSA2 DSM is carefully quality controlled to remove at least 95% of all artefacts that can occur during the generation process.
- Level 3 (L3) - the DEMSA2 DTM, where at least 95% of surface features taller than 1.5 m are removed from the L2 DSM.
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DEMSA2 L1 (left) and L2 (right)
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DEMSA2 L3 DTM overlayed on the L2 DSM
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Pricing:
DEMSA2 orders should kindly include a georeferenced polygon dataset (shapefile, kml, geopackage or any other format) delineating the area of interest (AOI). This AOI (or AOIs) will be used to calculate the price according to the below table. Please note that the table below shows a price estimate, and discounts can be offered on a case-by-case basis. Areas will be rounded to the nearest square kilometre for pricing. Note that 15% VAT will be added to the cost for South Africa-based clients.
| Product |
Small area (< 400 km²) |
Medium area (400 - 9 999 km²) |
Large (> 10 000 km²) |
Turnover time |
| DEMSA2 DSM (Raw) | R2 200 per AOI + R35 per km² | R25 per km² | R22 per km² | 5 workdays per 500 km² |
| DEMSA2 L2 (Quality Controlled) | R4 400 per AOI + R60 per km² | R45 per km² | R40 per km² | 20 workdays per 500 km² |
| DEMSA2 L3 (DTM) | R5 500 per AOI + R110 per km² | R90 per km² | R65 per km² | 20 workdays per 500 km² |
* Areas of interest must be rectangular, with a minimum width of 1km.
The requested DEMSA2 product is delivered as either a GeoTIFF raster as standard, but can be provided as a 50 cm vertical interval contour dataset in various geospatial polygon or CAD formats on request. An additional R500 processing fee will be charged when contours are extracted.
Additionally, the following ancillary datasets are offered as add-ons to an order:
| Dataset | Price |
| Orthorectified, high resolution (50 cm or above) RGB aerial imagery | R4 per km² |
| DEM derivatives (slope, aspect, solar radiation, topographical wetness index, soil moisture) | R2 per km² per derivative |
Product Specification:
| Resolution | 2 m |
| Vertical accuracy | ~50 cm |
| Horizontal accuracy | ~1 m |
| Price | See pricelist above |
IMPORTANT: DEMSA2 L1 and L2 are offered as a digital surface model (DSM), not a digital terrain model (DTM). In other words, DEMSA2 consists of the bare earth elevation and the heights of objects (e.g. trees, buildings) on the earth's surface. If you are interested in a DTM, please see the DEMSA2 L3. See the conceptual difference between a DSM and a DTM in this image:
