 As human analysts using the technique lead to subjective biases , efforts have been made to make more objective estimates using computer programs , which have been aided by higher @-@ resolution satellite imagery and more powerful computers . Since tropical cyclone satellite patterns can fluctuate over time , automated techniques use a six @-@ hour averaging period to lead to more reliable intensity estimates . Development of the objective Dvorak technique began in 1998 , which performed best with tropical cyclones that had eyes ( of hurricane or typhoon strength ) . It still required a manual center placement , keeping some subjectivity within the process . By 2004 , an advanced objective Dvorak technique was developed which utilized banding features for systems below hurricane intensity and to objectively determine the tropical cyclone 's center . A central pressure bias was uncovered in 2004 relating to the slope of the tropopause and cloud top temperatures which change with latitude that helped improve central pressure estimates within the objective technique . 
