28 IEEE Geoscience and Remote Sensing Society Newsletter• September 2010 energy. Typical rain events at the west coast last an average of three hours so that the eight hours of continuous operation should be enough for most cases. Figure 3 shows students installing the solar panels on top of a building located in Las Mesas hill. The CAC games at Mayagüez provided the opportunity to test for the first time a network of OTG radars in a tropical and mountainous region. In addition to the OTG radars, the CASA PRTB also counts with another X-band radar donated by EWR. All of these radars were modified and installed by undergrad and graduate students from the CASA PRTB which includes collaboration with the Universities of Massachusetts, Colorado State, and Oklahoma. The first OTG radar (OTG-1) was modified by replacing the 41” fan-beam antenna by a small parabolic reflector dish with a beam width of 3.8 degrees, the data collection interface and an embedded computer were integrated to the radar to complete the system [Pablos-Vega et al., 2010]. In addition, a wireless communication link was also established to move the data from remote places to a server located in the main campus. Solar panels and batteries were added to keep the system operating in case there was a power failure (the OTG has the capacity to operate with solar energy, but electricity from the power grid was used if available). The OTG-1 was calibrated at the CSU-CHILL facilities (See Figure 4) and then used to properly calibrate the OTG-2, OTG-3 and OTG-4 radars at Puerto Rico.