No abstract

This paper proposes a real-time local positioning system (RT-LPs) utilizing a mobile platform equipped with three anchor nodes placed in a right-angle triangle formation for a real-time locating system (RTLS). After deriving an analytic formula to calculate the target position utilizing the measured distances among anchor nodes and the target node, we find that four parameters have an effect on the position error of the target node. The spacing between anchors is a design parameter that must be large enough to the reduce position error. However, the distance from the anchor node to the target node is an operation parameter that must be small enough to reduce the position error. Additionally, the measured ranges among the anchors and the target node have probabilistic distributions with a mean and variance, which are dominant parameters that have effects on the position error. A comparison study was conducted to determine the effects of the parameters of the target position in both a simulation and an experiment, showing rates of approximately 4% ~ 10%. These findings indicate that our simulation can work properly with the proposed method after assuming that the distance error is a Gaussian model.

No abstract

Lapan-A2 Satellite, also known as LAPAN-ORARI, is the second satellite developed by the Indonesian National Institute of Aeronautics and Space (LAPAN) especially by Satellite Technology Center. This satellite was launched in 2015 which one of the payloads is for amateur radio communication such as VR (Voice Repeater) and APRS (Automatic Packet Reporting System). The APRS is a method of transmitting messages, status and positions using certain range of frequency and often used by Search and Rescue (SAR) team. Due to its function, APRS are not only used for disaster mitigation but also transmit various kind of data such as text message and weather information. In order to receive such information, APRS must be equipped with supporting devices. Formerly, APRS utilize terminal node controller and special hardware to decode its information but those technology is quite expensive. To address that challenge, this paper proposed an alternative way to decode the information send both from satellite APRS and terrestrial APRS by using raspberry Pi to replace those high-cost system.