# Smart Sensors and Smart Data for Precision Agriculture: A Review
## 3 Data Collection and Management Techniques
For the experiment, the authors carried out meticulous calibration procedures for both the camera and the algorithm used to calculate leaf area, thus ensuring the accuracy of leaf area determination and minimizing errors in different regions of the camera's field of view. With the aim of improving resource utilization by providing real-time data for informed decision-making, a study [119] presents a new approach to agricultural and irrigation monitoring via a Wireless Sensor and Actuator Network (WSAN). The Agrinex wireless network uses a mesh configuration of field nodes serving as sensors for soil moisture, temperature, and humidity, and actuators regulating drip irrigation valves. The dynamic mesh network enables sensor nodes to self-organize in response to changes in the network. The irrigation actuator integrates an electronically controlled actuator and valve, guaranteeing energy efficiency thanks to the use of a rectifier (IRF530). The system presents a promising framework for WSAN applications, particularly in agriculture, highlighting the integration of components for efficient data processing and actuation in the Agrinex system. The authors of [120] explore the challenges and solutions involved in implementing PA in greenhouses, focusing on the deployment of a LoRaWAN-based sensor network. Conducting real-time experiments at a research center in Belgium, the study presents a dashboard for data visualization, evaluates energy consumption in LoRaWAN communication, and tests different types of boxes. One notable discovery is the significant impact of temperature and humidity on sensor readings, addressed through an innovative airflow housing design. Focusing on energy-saving IoT strategies, the paper discusses implications for sensor enclosure design, advocates airflow enclosures, and proposes sequential steps for WSN deployment and monitoring. The in-depth study demonstrates the deployment of a LoRaWAN network to monitor tomato crops, highlighting the importance of continuous environmental data monitoring in PA. Future directions include efforts to improve the energy efficiency of the LoRaWAN network through energy recovery methods. Cloud-Based Data Storage and Management  
The researchers in [121] present an innovative IoT-based agricultural monitoring system with a cloud-based mobile application designed to enable farmers to easily observe and analyze their farms in real time. The system integrates various agricultural sensors such as humidity, temperature, and moisture with the Raspberry Pi, storing the data on the ThingSpeak cloud for future forecasting and improving crop quality. In addition, a Passive Infrared Sensor (PIR) is integrated to monitor potential intrusions. The study focuses on live monitoring of sensor values via cloud computing and a mobile application, providing a cost-effective, user-friendly solution that enables farmers to manage their farms efficiently and improve crop quality by minimizing wasted energy and resources. The proposed system, successfully implemented and tested, combines Raspberry Pi technology, IoT, and a cloud-based software architecture to streamline farming tasks and information processing. The ThingView mobile app serves as a graphical user interface compatible with Android and iOS operating systems, offering a complete solution for data visualization and farm monitoring. Interconnected components, including various sensors and a microcontroller board, facilitate the seamless flow, processing, and storage of data in the cloud. The connections between sensors and processors highlight the integration of sensors such as DHT11, PIR, and soil moisture sensors with the Raspberry Pi, demonstrating the practical implementation of the proposed system. The study presented in [122] addresses the challenges of traditional detection technologies for pest and disease detection in specialty crops, proposing the use of small UAVs equipped with a variety of sensors.