GNSS Markets and Applications - Understanding GPS: Principles and Applications - page 649

12.3.3 GIS
Anyone charged with the responsibility of managing a distributed inventory, such
as might be the case with a utility, municipality, or steelyard, might appreciate the
ability to locate and identify this inventory quickly and accurately. This is the role
played by GPS in conjunction with GIS. The last decade has seen a proliferation of
GIS software packages and programs. Government agencies and utilities have been
eager to adopt this technology, but find that the initial input of data and timely
updating thereof is a huge task using conventional means of data collection. With
GPS, it is possible to capture position-referenced data in the field with a simple
handheld computer. The situation is best illustrated by the example of the manage-
ment of a municipality's streetlights. There may be a mix of fluorescent, sodium,
mercury, and incandescent lights, with several varieties of each. The maintenance
engineer capable of recognizing the types can be dispatched with a GPS-based data
collector to log the location of each type of installation. This information can be
loaded into a central database, so that when maintenance is necessary, the appropri-
ate replacements can be ordered, stocked, and dispatched. Steel mills store large
quantities of product in huge yards, stacked in such a way as to prevent warping.
The stacks must be rotated periodically, on a set schedule. Further, there are differ-
ent types of products that are indistinguishable from one another, except for the
record of where each was put. The layout of these yards does not lend itself to physi-
cal marking, so accurate GPS can be used to locate each stack and reference its con-
tents to a central database. The management of other yard inventory items such as
shipping

containers or lumber is similar, and GPS applications have been

investigated here also.
A rapidly growing and highly visible endeavor is the management of natural
resources. Environmental impact studies involve the collection of large amounts of
position-related data, and GIS is prevalent here, too. GPS is instrumental in collect-
ing data to provide input to animal population studies and the like.
Finally, a whole new discipline, referred to as precision farming, or farming by
the foot, has emerged. The application of pesticides, herbicides, and fertilizers is
becoming an increasingly exacting science. Many farm implement manufacturers
are producing variable-rate application equipment that is controlled by sophisti-
cated electronics coupled to a sort of GIS. It has been shown that material input
costs can be reduced by 40%, and yield enhancements of a similar magnitude can be
expected. Furthermore, the harmful effects of the runoff of unneeded fertilizers can
be mitigated. It is possible that the variable application of fertilizers might be legis-
lated for this reason. GPS of course is central to the soil mapping to determine
requirements and to the control of application vehicles.
Several firms offer products to guide airborne applicators of pesticides. These
systems involve customized mapping routines to direct the pilot of crop duster
swath by swath over a particular field. This allows the replacement of
the flagperson, who would direct the pilot from the ground (a job in a very hazard-
ous environment), with more accurate electronic guidance. This reduces the
amount of overspray and can significantly decrease the amount of time and material
used.