The CASA project is an NSF Engineering Research Center investigating the design and implementation of a dense network of low-power meteorological radars whose goal is to collaboratively and adaptively sense the lowest few kilometers of the earth's atmosphere.  In the first part of this talk we overview the CASA project, describe its computing and networking challenges, and overview the software/network architecture and implementation of the CASA testbeds. We also discuss the operation of  CASA’s testbed during this spring’s tornado season in Oklahoma.  In the second part of this talk, we focus on networking-related research issues and discuss our experiences in using user-specified preferences to drive the optimization of the network's radar scanning behavior. Throughout the talk, we’ll discussion of a number of interesting on-going and open research issues.