however. Lasers can be quite small and inexpensive,
in order to reduce personnel costs and safety haz-
and if lasers would be capable of measuring vari-
ards. If data are to be remotely collected, this in-
ous parameters, then an inexpensive, compact por-
formation needs to be transmitted to a central lo-
table instrument could be developed.
cation for storage (and processing). A number of
sites are already equipped to do this through the
Summary of instruments
use of DCPs. The use of DCPs in the USACE is cov-
The Water Resources Division of the U.S. Geo-
ered by policy contained in ER 1110-2-248 (USACE
logical Survey has principal responsibility within
1981) and ER 1125-2-308 (USACE 1986). Data col-
the Federal government for collecting hydrologic
lected at a DCP are transmitted via the Geostation-
information and appraising the Nation's water re-
ary Operational Environmental Satellite (GOES)
sources. In order to better serve their field offices,
Data Collection System (DCS) operated by the Na-
a Hydrologic Instrumentation Facility (HIF) was
tional Earth Satellite Service (NESS) of the National
established in 1980 to centralize (and standardize)
Oceanic and Atmospheric Administration (NOAA).
instrumentation research, development, testing,
The USACE is limited to specific channels for data
evaluation, procurement, warehousing, distribu-
transmission and all data transmitters must be cer-
tion, repair, and calibration services for USGS in-
tified by NOAA/NESS prior to implementation. All
strumentation. The HIF is located in the National
transmission frequencies must be requested first
Space Technology Laboratories (NSTL) northeast
through the Water Resources Support Center, Data
of New Orleans on the Mississippi Gulf Coast
Collection and Management Division (WRSC-C).
(Wagner 1986). Future budget constraints may re-
Obviously, a data site cannot be selected and set up
quire more cooperative effort between Federal
overnight if data are to be transmitted from the site
agencies, and the HIF would be a good agency to
via DCP. The use of the GOES/DCS also requires
cooperate with in developing instrumentation for
that only environmental data be transmitted; trans-
certain ice-related measurements.
mission of operational data, such as gate opening,
Table 8 summarizes some of the advantages and
is not allowed.
disadvantages of different methods and instru-
Remote sites may be queried by phone or radio
ments. As can be seen, some instrumentation rates
instead of DCP transmission. Information could
highly in terms of ready implementation and low
be downloaded from the on-site data storage de-
cost, but are in areas that not many users rate high.
vice (e.g., a data logger) to a central computer
On the other hand, some of the more promising
through a modem. This technology has been com-
instrumentation for areas highly rated by users are
mercially available for a number of years and may
a few years away from being field-ready and will
prove more feasible and cost-effective, as modem
likely be expensive.
speeds continue to increase and phone transmis-
sion lines improve in quality. The use of cellular
phones could allow data collection at sites with
portable instrumentation or where telephone lines
EVALUATE SYSTEMS FOR TRANSMITTING,
are unavailable. A cellular phone will only be ef-
DISPLAYING, EVALUATING, AND STORING
fective, however, where there is adequate cellular
RIVER ICE DATA
coverage; many sparsely populated or rugged ter-
An important aspect of data collection that may
rain areas will not have adequate coverage. Ra-
often be overlooked is the storage and retrieval of
dios can be used at remote sites for transmitting a
data. This section provides a cursory overview of
warning signal, but radio signals may be suscep-
what happens to data once it is collected, includ-
tible to disruption in heavily populated areas or
ing transmission, display, evaluation and storage.
during severe weather.
Existing systems are generally adequate for stor-
Data collected manually could be sent to a cen-
age needs and will continue to be as computer
tral site via fax. Processing of the fax on the re-
systems evolve.
ceiving end would likely entail use of optical char-
acter recognition (OCR) software in conjunction
with a scanner (software does exist that allows a
Transmitting data
The first step in storing data involves the trans-
fax to be used as a scanner, but OCR-capability is
mission of that data once it is collected, whether it
unknown). While OCR software is quite good at
be sent from a DCP site hundreds of miles away
reading typed pages, it fares more poorly with fax
or recorded in the observer's notebook across
documents and even worse with handwritten
town. The trend is toward remote collection of data
documents. Eventually OCR software will be able
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