The verb go can mean to move or proceed from one place to another—whether it’s physically hopping onto a bus or flying to India. It can also refer to a plan or idea, as in the example of “go ahead and make the call.” When strawberries and apples go together, they don’t argue; they just go! But there are many other meanings of the word, such as the phrase “go with the flow.”

The National Oceanic and Atmospheric Administration (NOAA) uses a constellation of geostationary equatorial satellites—known as the GOES system—to monitor severe weather and natural hazards. These satellites are parked in geosynchronous orbit 35,790 miles above the Earth, where they stay fixed relative to the Earth’s rotation.

NOAA’s GOES satellites are equipped with sensors that capture the electromagnetic spectrum from both visible and infrared radiation. They can detect reflected sunlight off the surface of the ocean and atmosphere, track cloud movement, and provide images of the entire United States or a particular hemisphere every 30 seconds. GOES data can help forecasters predict the progression of dangerous weather events such as severe thunderstorms, hurricanes and wildfires.

GOES satellites have been a vital part of NOAA’s weather monitoring and forecasting capabilities since the launch of SMS-1 in 1974. NOAA oversees the operation of GOES, while the National Aeronautics and Space Administration (NASA) manages the design and procurement of the satellites and their payload instruments.

A GOES satellite has two primary instrument sets, an imager and a sounder. The imager provides continuous visual and infrared imagery, while the sounder measures the vertical structure of the atmosphere with sensors for its temperature and moisture content.

All GOES satellites are designated with a letter prior to launch, and once they achieve their orbit they are assigned a number. The current GOES satellites are GOES-13, operating as GOES-East at 75 degrees west longitude and GOES-15, operating as GOES-West at 135 degrees west longitude. The upcoming GOES-R series will maintain this two-satellite system.

Throughout the years, as new technology became available, GOES satellites were modified to incorporate these advancements. For instance, the GOES-9 and -10 satellites introduced an advanced imager and sounder. The VISSR on the GOES-9 and -10 satellites offered three times more spectral channels than the previous imagers, with much higher resolution and scanning rates.

The GOES-16 and -17 satellites launched in 2021 feature an advanced Enhanced Visible Imager (EVI) that has a number of innovative features, including a more robust thermal infrared capability, as well as an improved Atmospheric Sounder (ASU). The Enhanced Visible Imager can detect even the smallest clouds, and the Atmospheric Sounder can provide more information about the atmospheric temperature and moisture profiles at all altitudes. These advances will allow meteorologists to monitor a wide range of critical weather phenomena with greater accuracy.