Wireless sensor networks are tremendously being used in different environments to perform various monitoring tasks such as search, rescue, disaster relief, target tracking and a number of tasks in smart environments. Many applications in wireless sensor networks require sensor nodes to obtain their absolute geographical positions. There are various localization algorithms have been recently proposed. Localization - finding the position of individual sensor nodes-remains one of the most difficult research challenges. Many applications based on networked sensors require location awareness, a node must be able to find its location.