Service robotics is becoming a reality in many aspects of daily life due to the successful merger of several enabling technologies from the fields of Information and Communication Technologies. The growing availability of mass market products is also driving innovation towards automation in several civil and scientific areas. Specific applications such as precision farming, surveying, rescue operations and remote exploration can benefit from such modern and affordable robots, thus helping humans in work-related or daily life. To support such a new generation of service robots and vehicles, navigation capabilities play a fundamental role in mission planning and on-field activities. In parallel, recent developments of ultra-low cost embedded Global Navigation Satellite System (GNSS), such as in Android™ smartphones has enabled affordable Location Based Services (LBS) applications and provided an impetus to research into low cost navigation solutions. Modern smartphones come with an advantage of having a ubiquitous network infrastructure with ease of developing interconnected applications and integrated proprioceptive and exteroceptive sensors. Within the framework of precision agriculture promoted by the Politecnico di Torino Interdepartmental Centre for Service Robotics, this work investigates a low-cost navigation strategy for an Unmanned Ground Vehicle (UGV) – Unmanned Aerial Vehicle (UAV) paradigm exploiting a collaborative ranging technique based on Differential GNSS (DGNSS) approach applied on raw measurements exchanged between Android™ smartphones.