Radio and optical alignment method based on GPS

Abstract

Point to point communication in free-space is severely dependent upon the alignment of the transmitter and receiver devices. The simplest low cost method for the alignment is achieved by utilising two geographical coordinates and an electronic compass. However, some regions of the Earth have a strong magnetic deviation that can introduce large errors to such systems. Other known methods, that can be utilised are a radio direction finder or stars sensor however these methods are too expensive. Here, we present a system which uses three GPS coordinates for the alignment of the transmitter and the receiver, of which two coordinates are measured on the transmitter side, while the receiver is previously known. The transmitter side positions can be relocated for convenience. The methods were tested using Google™ Maps for a long distance within the northern and southern hemisphere, while the experiment was performed for a short distance within the southern hemisphere. The system was developed based on the following considerations: • Algorithm Implementable into a Micro-Controller Unit (MCU) or a standard computer. • The local magnetic deviation does not have any influence on the method. • Can be use where the internet connection is not available, such as mountains and others remote areas. Method name: Coarse alignment for optical communication and fine alignment for radio communication, Keywords: Tracking system, Optical transmission, Radio link