Target searching is one of the challenging research areas in defense. Different types of sensor networks are deployed for searching targets in critical zones. The selection of optimal strategies for the sensor nodes under certain constraints is the key issue in target searching problem. This paper addresses a number of target searching problems related to various defense scenarios and introduces new strategic approaches to facilitate the search operation for the mobile sensors in a two-dimensional bounded space. The paper classifies the target searching problems into two categories: preference-based and traversal distance based. In the preference based problems, the strategies for the mobile sensors are determined by Stable Marriage Problem, College Admission Problem, and voting system; they are analyzed with suitable examples. Alternatively, traversal distance based problems are solved by our proposed graph searching approaches and analyzed with randomly chosen examples. Results obtained from the examples signify that our proposed models can be applied in defense-related target searching problems.

Marine vessels in today's age are fitted with a number of state of the art systems required for their smooth operation. The compartments which house such systems along with the restricted compartments onboard ships such as the ships galley, dry rations store, cold rooms, battery compartments etc are required to be monitored on real time basis for temperature, pressure, humidity for detecting various hazards like fire, flooding etc. In addition, military platforms also need to monitor compartments such as the armory and magazines to avoid damage to munitions and prevent unauthorized access. The present project aims to develop a proof of concept prototype real time parameter monitoring and motion detection system for critical/restricted compartments on marine platforms with data logging capability.
Various sensors forming a sensor suite have been interfaced to the Raspberry Pi board, forming the Data Acquisition Console which is the nodal control center. As most marine vessels are fitted with a shipboard Local Area Network, the project utilizes this existing network for relaying data. The console is placed in the compartment where parameters are to be monitored and the measured data is acquired and transferred via wireless (using Access Points (APs) operating on Wi-Fi/ 802.11 network) or via wired connectivity with the nearest switch and be accessed by concerned personnel at various nodes/ computer on the . The performance of the DAC was successfully ascertained by comparison of sensor performance with other independent sensor readings. The measurement errors were found to be within the permissible accuracy limits of the sensors. Motion detection was achieved by using PIR motion The probability of detection (Pd) for the motion sensor was calculated by conducing iterative motion tests with favorable results. Data is displayed in a web-based dashboard Graphical User Interface. Further, provision has also been made to set visual alarms whenever a particular sensor reading crosses a pre-designated safe limit.