**7. References**


**9** 

*University of South Alabama United States of America* 

**PILS: Low-Cost Water-Level Monitoring** 

The estuarine environment is important both to global ecology and to human economy. Estuaries are the place where freshwater meets saltwater, and so they typically contain a bounty of marine species, and are essential to the life cycle of many marine organisms. For

In order to study estuaries in more detail, we have developed two sets of low-cost sensors using off-the-shelf technology combined with innovative new low-cost circuits. The first, nicknamed "Jag Ski", is a highly mobile water craft for navigating estuarine and littoral areas and providing real-time data. The second, named "PILS", is a network of stationary sensors for making long-term water-level measurements. This paper describes the

Sensing the environment can be carried out through remote measurements (e.g. satellites (Villa & Gianietto, 2006)) and through in situ measurements (e.g. wireless sensor networks (O'Flyrm et al., 2007; Thosteson et al., 2009)). Both have been demonstrated successfully as

An example of one real-time water-sensor architecture is the Land/Ocean Biogeochemical Observatory (LOBO) system developed by Satlantic and the Monterrey Bay Aquarium Research Institute (MBARI) (Comeau et al., 2007; Jannasch et al., 2008) and has been installed in the field (Sanibel-Captiva Conservation Foundation, 2009). Others include the Ocean Observation Initiative (OOI) (Frolov et al., 2008; National Research Council, 2003; U.S. Commission on Ocean Policy, 2004), NOAA tide gauges for storm surge (Luther et al., 2007), and sonar-based water-level measurements (Silva et al., 2008). Specific to environmental monitoring in the coastal ocean, mobile field assets typically include profiling floats (Roemmich et al., 2004), autonomous underwater vehicles (AUVs) (Rudnick et al., 2004), and unmanned underwater vehicles (UUVs) (Freitag et al., 1998; Frye et al.,

This work is in line with these earlier systems. We have adapted the mobile sensor platform to a highly maneuverable manned platform to navigate shallow-water areas proficiently. The sensor network is designed for relatively low cost and for unattended measurements. It

similar reasons, they often contain sea ports and carry commerce of great value.

construction of both, along with actual measurements.

means of measuring characteristics of water.

also contains novel sensors for pressure and salinity.

**1. Introduction** 

**2. Survey of literature** 

2001).

Samuel Russ, Bret Webb, Jon Holifield and Justin Walker

