This paper provides an overview of measurement techniques and one-hop localization algorithms in wireless sensor networks (WSNs). It discusses angle-of-arrival (AOA) measurements, distance-related measurements (one-way and roundtrip propagation time, lighthouse approach, and time-difference-of-arrival (TDOA) measurements), and received signal strength (RSS) profiling techniques. The paper also covers multihop connectivity-based and distance-based localization algorithms, and addresses open research problems in distance-based sensor network localization. The focus is on 2D localization problems, with detailed discussions on AOA, TDOA, and RSS measurements, as well as their applications in one-hop localization techniques. The paper highlights the challenges and advancements in WSN localization, emphasizing the importance of accurate and efficient localization algorithms for various applications such as environmental monitoring, inventory management, and surveillance.This paper provides an overview of measurement techniques and one-hop localization algorithms in wireless sensor networks (WSNs). It discusses angle-of-arrival (AOA) measurements, distance-related measurements (one-way and roundtrip propagation time, lighthouse approach, and time-difference-of-arrival (TDOA) measurements), and received signal strength (RSS) profiling techniques. The paper also covers multihop connectivity-based and distance-based localization algorithms, and addresses open research problems in distance-based sensor network localization. The focus is on 2D localization problems, with detailed discussions on AOA, TDOA, and RSS measurements, as well as their applications in one-hop localization techniques. The paper highlights the challenges and advancements in WSN localization, emphasizing the importance of accurate and efficient localization algorithms for various applications such as environmental monitoring, inventory management, and surveillance.