Sharper, faster images off new satellite will improve future forecasts
Posted January 24
GOES stands for “Geostationary Operational Environmental Satellite,” the series of satellites that are parked in orbits about 22,000 miles above the equator, where they circle the earth at a rate that matches the earth’s rotation, allowing them to stay in the same relative location and provide the kinds of images that we can animate into loops and movies that show the movement and evolution of weather systems. In addition to providing those images, the satellites also make estimates of winds at varying levels of the atmosphere, measure and map surface temperatures, and they can derive profiles of moisture and temperature through the depth of the atmosphere.
GOES-R (the development and pre-launch designation for the system) is now on orbit and undergoing testing and calibration as "GOES-16," and on Monday, NASA and NOAA released a series of images that highlight the quality of the views we’ll be working with once it becomes fully operational later this year.
I’ve included three of the images that were released Monday as a small sample of what the new satellite is capable of – first, a comparison of the full-disk image from GOES-16 to that of the current operational satellite (GOES-13). While the difference in color is what first jumps out at you, the image is also noticeably sharper, although this would be even more evident when zoomed in to smaller portions of the earth.
The second image is a medium-close view of the southeastern U.S. and the Caribbean, and highlights nicely just how detailed the new images can be (keeping in mind that this is the view from 22,000 miles away!).
Finally, there is an image that illustrates the same view as seen at each of the 16 wavelength bands used by the ABI. One interesting point here is to note that none of these is an actual "color" image. Instead, the simulated, full-color views are made by combining data from the two visible images with one of the near-infrared bands, along with some additional processing that is based on estimating what a third "green" visible image would have provided. As you can see in the other images, the results of this process are quite striking.
If you’re interested in more details about this new capability, check out the program web site at http://www.goes-r.gov (the “Data Products” link there really highlights how much information will be provided by this satellite). You can also check out more of the sample images being received in the GOES-16 album on Flickr, and finally, NOAA is posting some animations from GOES-16 on YouTube.
While we’ve had some very capable geostationary satellites for quite a while now, the recent launch placed into orbit a greatly enhanced and upgraded platform for a number of instruments that will provide meteorologists and others with quite a few new and improved products.
Its main instrument is called the Advanced Baseline Imager (ABI), and is able to acquire imagery in 16 different wavelength bands, including 2 visible bands (blue and red), four near-infrared bands and 10 infrared bands. Using these measurements in a variety of combinations allows for more accurately discriminating clouds from smoke, fog, snow and volcanic ash, for example, and to produce imagery in a well-simulated version of true color.
Just as important, the new imagery has four times the horizontal resolution of the previous GOES satellites, providing much sharper detail and more clearly defining small weather features that can be important to short-range forecasts. Better yet, the instrument will provide new imagery at about 5 times the rate that the old one did, so we will be able, for example, to see new full-disk images of the entire western hemisphere every 15 minutes, the continental U.S. every 5 minutes, and, when needed for fast-moving, high impact weather systems (severe storms or hurricanes for example), the system can provide a new view every 30 seconds! The smoothness and detail that this will provide to satellite loops in these situations will be a great jump from what we’re used to seeing.
In addition to these kinds of visualizations, the data provided by the more accurate temperature, wind and humidity sounders should help with providing more accurate input data for computer models, especially in filling gaps between the locations where we regularly send up weather balloons, along with better filling the time spans between those upper-air observations (balloons are routinely launched at 12-hour intervals). There will also be upgraded estimates of rainfall rates and amounts that can help with water management, drought assessments and flood predictions, and also higher quality detection and monitoring of wildfires.
Another instrument on the spacecraft that has not been available in previous generations of GOES is the "Global Lightning Mapper." Currently, we have some highly capable, ground-based networks for detecting lightning, but they are limited to land areas and in many cases only detect and display cloud-to-ground lightning. The mapper on GOES-16 will provide continuous detection and display of all types of lightning, over land or water, which can be important in anticipating and tracking the intensity and development of storms, in some cases providing an early clue that a developing storm may become severe in the near future.
While that’s a brief overview of some of the features that all of us meteorologists are looking forward to, GOES-16 has even more capabilities that will monitor the sun and the near-space environment, assisting solar and space weather forecasters, as well as carrying equipment that supports the Search and Rescue Satellite Aided Tracking (SARSAT) System that receives signals from users with emergency beacons (aviators and mariners, among others) and routes those signals to emergency response centers that can direct rescue teams to the appropriate locations.