Thermal imaging can be a safety tool for bus transportation


BUSRide interviewed Bill Parrish, PhD, the co-founder, CTO, and chairman of the board for Seek Thermal, about thermography and the value it can provide to bus and coach operators dealing with the fallout of COVID-19.

Bill Parrish

What is thermal imaging and how does it work?

Thermal imaging, or infrared imaging, mimics precisely what the human eye does with visible light, except it “sees” a light that is of a lower energy (longer wavelength), which human eyes cannot detect.

Seek Thermal builds sensors that are very much like the cameras in cell phones. These sensors visualize long wavelength infrared, which allows us to see a person giving off infrared light. We can see that all objects give off a certain amount of infrared light. Depending on how much light we see, we can determine the person’s or object’s temperature. This practice is called thermography.

Thermal imaging and COVID-19 response

Today’s COVID-19 pandemic is daunting, but it made clear the need for quick temperature checks in public spaces. With careful calibration, these sensors can determine if a person likely has a fever.

It comes with some complexity. For example, the thermal imaging sensor might not detect the fever of a person who has just spent significant time outside in snowy weather. Likewise, the sensor may render a false-positive test for a person whose skin is warm from extremely hot weather.

It is, therefore, important to consider the environmental context of thermal imaging when rendering temperature checks. Body temperature is not a panacea because people are quite often sick and transmitting COVID-19 without showing any symptoms, including fever.

This can be especially problematic in places where people often have less choice about social distancing – including public transportation and group bus travel.

How can transportation providers take advantage of
this technology?

With bus transportation, thermal imaging can prove invaluable for determining if passengers are potentially sick. Sensors can be installed onboard the bus and can quickly scan passengers as they enter the vehicle (and, in the case of public transportation, pay their fare).

If there is a group of passengers boarding at single stop and only one passenger in that group is showing a higher body temperature, then it is a likely indicator of a fever. Thermal imaging should be viewed as a primary checkpoint before more rigorous safety protocols can be enacted by the agency or company.

Bus and coach operators know better than anyone that it is crucial that we maintain public health while also maintaining vital transportation lines across America. Thermal imaging can provide a critical first line of defense against the virus, which has disrupted public and private bus travel so severely.

Bill Parrish, PhD, is co-founder, CTO, and chairman of the board for Seek Thermal. He is one of the most well-known luminaries in thermal imaging having pioneered the technology for multiple industries, including military, industrial, consumer and more, since the early 1980s. Visit to learn more.