With the advances in sensor technology and improvements of algorithms for data processing, sensing systems are more widely employed. They are an important means of measuring physical quantities in virtually every domain; industrial automation, environmental monitoring, and infrastructure monitoring to just name a few examples. Sensing systems have different deployment strategies. A classical approach uses stationary mounted sensor systems for example in industry automation settings (e.g. sensing process variables). In recent years, mobile applications of groups of sensors have gained research interest in form of Wireless Sensor Networks (WSN), in which sensors combine the sensing capabilities with some local computation and wireless communication. WSN typically employ many sensors with same sensing capabilities, with a peer-to-peer communication for self-organization. Their strength lies in covering large areas through many (mostly stationary) sensors where the distributed sensing is combined into a single unified view of the covered area. Conversely, roaming sensors systems are sensor systems that are moved through and survey the area of interest (e.g. being mounted onto a survey vehicle). In result fewer sensors can be used to cover a larger area. However, roaming sensor systems are typically used for observing slow changing physical phenomena. This chapter discusses the system-level design of such roaming sensor systems.