What is the difference between overhead (vertical) people counters and horizontal counters?
There are two ways of placing sensors to count people: vertically overhead and horizontally. While the overhead method offers the highest precision, the horizontal view has its utility when one understands well the limiting conditions of operation. Our DS-10 and DE-10 sensors are examples of these two human circulation data acquisition methods.
Persons crossing the field of vision of an horizontally placed sensor will hide other people standing beside them. The denser the traffic, the more often will two or more people cross the sensor's field of view simultaneously, giving only one passage to the sensor. These extra hidden persons are invisible to the sensors.
These factors depend on traffic type and density. Horizontal traffic measurements only give estimates of variable precision. The denser the traffic, the less accurate the estimate. Horizontal estimation does, however, provide useful traffic profiles.
Using overhead counting sensors has two main advantages: accuracy and stealth.
Vertical traffic measurement is a good choice for high-density situations, when the user must have the highest accuracy possible and when aesthetics are a primary concern.