# Site Selection ### Overview Selecting an appropriate site is one of the most important factors in ensuring high-quality observations from a 3D-PAWS station. Even when sensors are functioning correctly, poor siting can result in measurements that are biased or not representative of local conditions. Site selection should prioritize **exposure, representativeness, and practical constraints**. *** ### Key Considerations When selecting a site, evaluate these factors: * **Exposure** – Are sensors unobstructed by buildings, trees, or terrain? * **Representativeness** – Does the site reflect the surrounding environment you want to measure? * **Solar Access** – Will the solar panel receive sufficient sunlight throughout the day? * **Communications** – Is cellular or WiFi connectivity available and reliable? * **Security** – Is the site protected from theft, vandalism, or accidental damage? * **Accessibility** – Can the station be safely installed and maintained over time? *** ### Instrument Siting Guidelines #### Rain Gauge * Place in an **open area** * Avoid obstructions (trees, buildings) * Avoid the **leeward side** of structures * Ensure precipitation can fall freely *** #### Wind Sensors * Install with **minimal obstruction** * Avoid areas where airflow is blocked or channeled * Consider **prevailing wind direction** *** #### Radiation Shield (Temperature / Humidity / Pressure) * Install in **well-ventilated air** * Avoid shaded or enclosed areas * Avoid heat sources (buildings, pavement) *** #### Solar Panel * Ensure **maximum sun exposure** throughout the day * Avoid shading from objects or terrain * Consider seasonal changes in sun angle *** #### Soil Sensors (if installed) * Place in **representative soil conditions** * Avoid artificially shaded or disturbed areas *** ### Balancing Siting Tradeoffs Perfect sites are rare. When compromises are required: * prioritize **rain gauge exposure** * maintain **good airflow** around temperature and humidity sensors * ensure **adequate solar power** Document all siting limitations in station metadata. *** ### Observing Practices and Standards 3D-PAWS follows the [*World Meteorological Organization (WMO) Guide to Instruments and Methods of Observation (WMO-No. 8)*](https://community.wmo.int/site/knowledge-hub/programmes-and-initiatives/instruments-and-methods-of-observation-programme-imop/guide-instruments-and-methods-of-observation-wmo-no-8), which provides detailed sensor exposure and siting recommendations. Applying these principles improves data quality and consistency. *** ### Summary A well-chosen site will: * minimize measurement bias * improve data reliability * reduce troubleshooting needs *** ### Instruction Slides for Site Selection {% embed url="" %}