Development of low cost X-Band Radar for rain reflectivity measurements in the western region of Puerto Rico

The Student Led Test Bed (STB) is part of the NSF Engineering Research Center CASA and is currently focused on developing low infrastructure radar networks to fill lower atmosphere gaps not covered by current technology. A low infrastructure radar network could significantly improve the time and spatial resolution of radar data for the lower atmosphere. There is a concern among National Weather Service (NWS) officers and emergency management people regarding the need for more accurate weather radar data to improve forecasts in some regions of Puerto Rico, more specifically in the western region. The low infrastructure radar and this network have been developed to address this particular concern. The network consists of three radars nodes in which the location of each node is strategically selected to cover the desired area. This research describes the development of the first node that requires no energy from the power grid, so it is then known as Off The Grid (OTG) X-band radar. The OTG radar was developed from commercially available marine radar. In addition to modifying the hardware to serve meteorological purposes, a photovoltaic system was fitted to power the radar using solar energy. The system underwent internal calibration and a cross calibration with the CSU-CHILL weather radar. Satisfactory results were obtained demonstrating that the OTG node can measure precipitation with the resolution required to meet lower troposphere measurement needs. Afterwards the OTG node was brought back to Puerto Rico and deployed in Mayagüez, where precipitation measurements were made to complement measurements taken with the NWS NEXRAD radar. The radar operates on solar energy during its operation period, and its data is transferred to a server via point to point wireless link to a server. The data is afterwards processed and displayed on a website. Due to the low infrastructure of the radar, it is easy to deploy on remote sites. This OTG node is the first of the low infrastructure X-band weather radar network that has been recently installed without a power grid to aid in forecasts for the western region of Puerto Rico, where lower troposphere measurements are important due to the variability of the terrain in the region and difference in height with the only NEXRAD radar located in Puerto Rico.