TerraColor® Global Imagery - Ocean Shaded Relief
Using our proprietary 15-meter resolution land/ocean mask, we have now developed three versions of TerraColor Global: one with a blue ocean fill color, and versions with two different types of bathymetric color shaded relief images. Pricing is the same for all three versions. The bathymetric color shaded relief images were generated from gridded sea floor topography*, and can add interest to global and regional views, and to provide information on the geology of plates, continents and islands. The following details can help you choose which version might be most suitable for your applications:
- Plain Blue Ocean fill (PO) version - This version uses a generic blue ocean fill, and this is the standard version of TerraColor Global. Users may prefer the PO version if a uniform global ocean color is desired, for smaller scale mapping where ocean relief shading may be distracting, flight simulations where a smooth blue ocean is more realistic, and other similar issues. The PO version ships with a set of auxiliary tiles to fill areas of the world where no land occurs. (You can also fill any empty areas with a blue background color for faster rendering in your application and not use the auxiliary ocean filler tiles.)
- Low Contrast Bathymetric Shaded Ocean (LCOS) version - This version fills the ocean areas with a bathymetric color shaded relief with a limited (low contrast) range of colors. The color palette used is a compromise that is designed to show sea floor features while also minimizing the impact of color changes between the LCOS image and actual water colors near land. Like the PO version, the LCOS version ships with a set of auxiliary tiles containing only the LCOS image to fill areas of the world where no land occurs.
- High Contrast Bathymetric Shaded Ocean (HCOS) version - This version fills the ocean areas with a bathymetric color shaded relief with a fairly wide range (high contrast) set of colors. This version is more colorful than the LCOS version, and is designed to maximize the visual portrayal of sea floor features for larger scale views (similar to Google Maps). However, significant color changes between the HCOS image and actual water colors near land may not be desireable for many applications. Like the PO version, the HCOS version ships with a set of auxiliary tiles containing only the HCOS image to fill areas of the world where no land occurs.
Note: When using TerraColor Global in web mapping applications, it is possible to combine two versions by using the LCOS or HCOS version for large scale views, and then transitioning to the PO version for smaller scale views. This is how we recommend that the product be used if your web mapping system is capable of this. We can provide a 150-meter resampled version of the HCOS or LCOS product at no additional cost if this is desired. (Esri does something similar to this in ArcGIS Online.)
* The shaded relief image used to fill TerraColor Global ocean areas was created from the Measured and Estimated Seafloor Topography dataset developed by Scripps Institute of Oceanography (with their permission). The spatial resolution of the bathymetric data is one kilometer (1000m), but has been smoothed to avoid pixelation next to the TerraColor 15-meter pixels.
Below are some examples of the three ocean fill options to illustrate the differences. More larger scale examples are shown on the 2-D Samples page:
Caribbean Sea with PO fill (left), LCOS fill (center) and HCOS fill (right)
Korea with PO fill (left), LCOS fill (center) and HCOS fill (right)
Persian Gulf with PO fill (left), LCOS fill (center) and HCOS fill (right)
Hong Kong, China with PO fill (left), LCOS fill (center) and HCOS fill (right)