We are excited to announce that starting immediately 40-cm satellite imagery products from DigitalGlobe’s constellation are ready for purchase! While the change in resolution from 50-cm down to 40-cm might sound like a 20% increase in the number of pixels you would receive, it is actually a 56.25% increase given that you will receive additional pixels in two dimensions. This can be a serious advantage for spectral and visual analysis where the features of interest are at the detection limits of 50-cm imagery products.
Here are some specifics on 40-cm DigitalGlobe imagery products to keep in mind when placing an order for this data:
(1) This change in resolution from 50-cm to 40-cm only impacts GeoEye-1 and WorldView-2 imagery. DigitalGlobe’s other sensors (i.e. IKONOS, QuickBird and WorldView-1) collect data with a ground sampling distance* equal to or higher than 50-cm.
(2) At nadir, GeoEye-1 collects 41-cm imagery and WorldView-2 collects 46-cm imagery. As the off-nadir angle of collection grows, so does the ground sampling distance; and so, in many cases, it would not make sense to deliver GeoEye-1 and WorldView-2 at 40-cm resolution. Your Apollo Mapping representative can help you decide if it makes to deliver these imagery products at 40-cm or 50-cm resolution.
(3) The change in resolution from 50-cm to 40-cm also impacts multispectral data. You can now order multispectral data at a maximum resolution of 1.6 meters.
(4) 40-cm imagery products will be offered at the same price as 50-cm products through the end of September 2014. Pricing for 40-cm products will be available from Apollo Mapping during August and will be published in the next newsletter when released.
(5) In some cases, 40-cm imagery products will take longer than 50-cm products to deliver given the extra processing and file sizes required for the increased resolution.
(6) New collections at 40-cm resolution are only available for these countries during Quarter 3 2014, they will start globally beginning Q4 2014:
- New Zealand
- South Africa
- Western Sahara
(7) In our September edition of The Geospatial Times, we will feature comparisons of 40-cm and 50-cm imagery products over the same locations.
For more information about these exciting resolution changes, please contact the Apollo Mapping sales team by email at [email protected].
* Ground sampling distance is used here to describe the area of ground that is covered by a single pixel during imaging, for example 41-cm for GeoEye-1 when collected directly at nadir. Resolution is differentiated then from ground sampling distance as it is the area of the ground covered by each pixel in the imagery, for example 40-cm or 50-cm for GeoEye-1 products.