Real time locating systems (RTLS) with centimeter accuracy have recently been made available for commercial deployment by employing ultra wideband (UWB) technology. DecaWave's DW1000 is a commercial UWB integrated circuit that utilizes time-of-flight (ToF) measurement technique and two-way-ranging (TWR) mechanism to accurately estimate the distance between an anchor and a tag. With the distances between the tag and at least three anchors, a trilateration algorithm can be applied to estimate the tag's location on the same two-dimensional (2D) plane as the anchors. Moreover, if four or more anchors are available, the tag's location in threedimensional space can also be estimated. This work presents a performance study on location accuracy of DecaWave's TREK1000, a two-way ranging RTLS IC evaluation kit. Four anchors and one tag were set up as an RTLS deployed in two different indoor areas. The difficulties encountered during the calculation of the tag's location at certain locations were pointed out. It was also found that the change in performance of the 2D localization of the system when set up with three and four anchors was insignificant. Additionally, the accuracy in the third dimension or the height of the tag above the ground was found to be less accurate.

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Every manufacturing process leaves waste to environment. Some waste must be controlled. Some waste can be utilized. Like the organic fertilizer plant, it leaves waste from chicken manure digestion of bacteria. The air pollution has ammonia gas and heat. The gas has to be deodorized by deodorizer tank. On the other hand, the heat can be harvested for electrical energy. The plant needs to monitor ammonia gas level in the waste out air. We propose a design the energy harvest appliance to produce electrical power from a temperature difference which is caused by heat energy on surface of the deodorizer tank. The electricity powers wireless sensors which check quality of the waste air. The thermoelectric generator (TEG) is used to convert the heat energy to be electrical power. It converts temperature gradient between its hot side and cool side to be electrical power based on the Seebeck effect. For long life time, the two energy storage concept (a super capacitor primary storage and a battery secondary storage) is used and the power management is proposed. The system can work and stand alone. The experimental results show that the system can generate continual power up to 290mW.

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