Dvorak technique
Beginning with the launching of TIROS-I in April 1960, satellites have been used to look for tropical cyclones. The Dvorak technique was developed from early satellite images of tropical cyclones to determine real-time a tropical cyclone's strength from characteristics seen on satellite imagery. In most tropical cyclone basins, use of the satellite-based Dvorak technique is the primary method used to determine a tropical cyclone's maximum sustained winds. The extent of banding and difference in temperature between the eye and eyewall is used within the technique to assign a maximum sustained wind and pressure. Since the mid-1990s, microwave imagery has been able to determine the center of rotation when that center is obscured by mid to high level cloudiness. Cloud top temperatures are used in real-time to estimate rainfall rates within the cyclone.