Specifications

11
These new radios are filling th e void left by other protocols in medium scale, low-
power networking. Devices using ZigBee need little work to setup a self-healing, scalable
network [20]. This leaves the host device interfacing with these radios needing only to be
programmed with data management and database routines, leaving the network topology
to the protocol. The maximum network size is limited by the protocol to be less than 64,000
nodes [19].
2.4 Missing Analysis Opportunities
Sensor networking is the practice of taking sensors and embedding them with intelli-
gent wireless data-links. An artifact of sensor networking is data fusion [21]: th e combining
of multiple measurements and data types to infer an attribute generally b eyond a single
source or source type. Some algorithms developed in data fusion include localization and
directed diffusion algorithms, distributed tracking in wireless ad hoc networks, and dis-
tributed classification using local agents [22, 23]. Data fusion algorithms can be used to
increase accuracy of noise-prone sensors [24]. Common algorithms use least mean square
(LMS) censuses [25], Bayesian [23, 26], and Kalman filter and Dempster-Shafer evidence
theory [27]. All of these algorithms provide ways of extrapolating meaningful indicators
that can be used in automation and to advance analysis or modeling efforts [28].
2.5 Survey of Existing Product
Various companies specializing in creating products to collect environmental data have
produced dataloggers which offer many of the features described in section 1.3. Four of these
businesses and their currently available products will be discussed in sections 2.5.1-2.5.4.
All of these loggers work well and have established their place in providing services to their
respective target communities. All of theses products will be reviewed using section 1.3.
2.5.1 Campbell Scientific Incorporated
Campbell Scientific [29], a company based in Cache Valley, Utah, is a world renowned
maker of rugged data logging and measurement equipment. They have offices and produc-