TerraColor NextGen Frequently Asked Questions

This FAQ will help you learn more about the NextGen product and determine whether it is right for your needs. If you have questions not covered here, please use our Contact form.

What does "15-meter resolution" mean?
Resolution refers to the amount of detail in the imagery, and 15 meters refers to the ground dimensions of one pixel in the image. (So, one pixel covers a 15x15 meter patch of the ground.) This level of detail is sometimes called "medium resolution" and designed to create images of the complete globe all the way down to images of mid-size cities. Below is a full resolution snapshot of Singapore harbor:

Can I see individual houses or cars in NextGen imagery?
NextGen's 15-meter resolution does not provide enough detail to clearly see individual houses, cars, and similar smaller size features. For that, you need high resolution imagery, which is offered by other vendors.

How new is the NextGen imagery?
For much of the world the imagery dates are between 2014-2018. With our recent new release, we upgraded many key areas of the world with 2018-2019 imagery. For more details, see the Specifications page.

What is true color imagery and why is it important?
Most satellites image the earth in a variety of spectral bands (or wavelengths of light). Some of these  are visible to the human eye (like green light) and some are not (like infrared light). A true color image is created when the image is built from the satellite's spectral bands corresponding to the red, green and blue wavelengths of light. Since the human eye is also sensitive to red, green and blue light, the NextGen image colors look "true" much the same as a person would see them from an aircraft. (Sometimes the terms "true color" and "natural color" are used interchangeably, but we prefer true color so there is no confusion.) Not all satellite images are true color, some vendors create false color images incorporating infrared bands, then manipulate the colors to try to make it look more natural (we call this "simulated natural color"). Since the colors cannot look truly realistic, sometimes you end up with strange artifacts like a blue patch in the middle of a desert where there is clearly no lake. This can cause problems in understanding the imagery, and it may not match well with other true color imagery of the same area.

At what map scales can NextGen imagery be used?
NextGen imagery is appropriate for mapping scales from 1:60,000 all the way up to a complete global world map.

Does NextGen offer complete coverage of the globe?
Yes, unlike some other vendors, we offer off-the-shelf coverage of the entire planet with no gaps or holes. This makes NextGen perfect for virtual globe applications that require full coverage of the globe.

Does NextGen have imagery of Antarctica and the Arctic Ocean?
Yes. For Antarctica, we provide 15-meter imagery to 85 degrees south, and lower resolution imagery to fill the area from 85-90S where the Landsat satellites have no coverage. In 2019 we updated many important areas of Antarctica with new imagery, such as the entire Antarctic Peninsula and several coastal ice shelves. For the Arctic area, we provide new 15-meter imagery to 85 degrees north, and use lower resolution imagery to fill the small area north of 85 degrees (the northerly tips of Greenland and eastern Canada). We show the Arctic Ocean area without sea ice, so only the land masses are shown.
Do you provide terrain/elevation data to complement the NextGen imagery?
We recommend the ASTER Global Digital Elevation Map V3 (GDEM) dataset for use with NextGen since it is a high quality product sampled at a complementary resolution (~30 meters/pixel). GDEM is a public domain dataset that can be downloaded free of charge from several websites. It has coverage from 85N to 85S so it covers most of the globe, and is provided in 1x1 degree tiles in GeoTIFF format. If desired, we can provide GDEM (used in our 3-D Perspectives gallery) along with purchases of NextGen upon client request.
How is NextGen used in web mapping products?
When creating a global web map, NextGen can be used to portray the world from a complete global view all the way down to the large city level. At that point the web map may change to using higher resolution imagery from other vendors to show details of buildings, houses, cars and smaller features as you zoom in.
Is there a 10-meter resolution version of NextGen?
Yes, we have a 10-meter version created by resampling the original 15-meter imagery and then applying an enhancement to it. The 10-meter version has the same information content as the 15-meter version, but is slightly sharper and crisper with a bit more local contrast. The 10-meter version also uses twice the  disk space of the 15-meter version. The difference between the 15- and 10-meter versions is not noticeable until the imagery is viewed at full resolution (1 pixel on the screen for one pixel in the image file). If you are interested, please contact us for details.
What if I don't need the full 15-meter level of detail?
For that case we offer a 150-meter resolution version of NextGen for a lower price. The 150-meter version uses very little disk space, which makes it a nice fit for off-line or embedded  applications where a good global map is needed at a compact file size. Contact us for details or samples.
What is an ocean mask and why is it used in NextGen's processing?
An ocean mask (or land/ocean mask) is a black and white image used to differentiate the land and ocean areas of the world so they can be processed separately. One reason we use this is to remove extraneous features in the ocean like ice, clouds, or edges of images and instead fill in a uniform blue ocean color to make a clean map that can be used off-the shelf with no editing. Another reason is that some clients want to see a different type of image in the ocean, such as a color shaded relief image showing bathymetric (ocean depth) features instead of blue ocean. Earthstar has developed a proprietary Variable-Density Ocean Mask (VDOM) that has soft edges to make a smooth transition from the land imagery and the selected ocean fill color or image. Our ocean mask is carefully made to retain nearshore ocean features that are important to understanding the character of an area. Examples include river outfalls, sandbars and coral reefs.
Below is a overview of the NextGen global land/ocean mask:
Can NextGen be customized?
Yes, we can customize NextGen to suit your needs or create a unique look. The two most common ways to modify the original NextGen product are changes to the overall brightness or contrast, and replacement of ocean areas with a bathymetric shaded relief image or other images or ocean colors. You can provide us with your own ocean images, or we can create them for you. Please contact us with your ideas and we can discuss the options in more detail.
How large is NextGen in file size?
In an uncompressed file format like GeoTIFF, the total file size for the NextGen global coverage is 5.5 TB (5,500 GB) for all tiles containing some land. 
Can I purchase NextGen imagery of a country or continent only?
Yes, you can purchase any area of the world. You can specify the country or region, use Lat/Long bounding box coordinates, or provide us with a Shapefile or KML file showing the desired coverage. See the Ordering page for details.
Can NextGen be downloaded via FTP?
Smaller areas can be provided to the client via FTP, but larger areas or the complete global coverage will be shipped on a portable external hard drive. 
How large of a print can be made with NextGen?
If printed at 300 dots per inch (dpi), you could use the NextGen full global 15-meter coverage to make a print about 220 meters in width by 110 meters in height (720 x 360 Feet). Or, Australia at 25.6 x 13.4 meters (84 x 44 feet).