\section{Introduction} \label{sec:introduction} The turn over frequency while sleeping is an important index to quantify the health of elderly. Many wearable devices can also achieve the same purpose, but many study show that the elderly feel uncomfortable with wearing such devices all days.\textcolor{red}{(source?)}. By the low resolution thermal camera, we can obtain the daily activities informations, but not reveal too much privacy like the RGB camera. {\bf Contribution} In this work, we deployed multiple low resolution thermal camera to monitor the turn over frequency while sleeping. With multiple thermal camera, Super-resolution techniques, and our method, we can have 50\% recall rate and 83\% precision on turning over detection. The remaining of this paper is organized as follow. Section~\ref{sec:bk_related} presents background for developing the methods. Section~\ref{sec:design} presents the system architecture, and the developed mechanisms. Section~\ref{sec:eval} presents the evaluation results of proposed mechanism and Section~\ref{sec:conclusion} summaries our works.