physiological limits, medical treatments, and mini- 
mum decompression times. 
—Environmental considerations. Environmental in- 
formation is critical to the design of reliable, 
efficient, and economic equipment for use in the 
oceans. 
—Data handling. Data are the product of scientific 
and exploration missions. Technology applied to 
marine data handling can vastly improve at-sea 
operations. 
—Life support. Extended underwater manned op- 
erations require advanced life support systems. 
A. Survey Equipment and Instrumentation 
1. Survey Equipment 
a. Current Situation Survey functions required 
for undersea operations result from needs for (1) 
measurement and sampling of ocean and sub- 
bottom parameters for geophysical, chemical, and 
biological analysis, (2) knowledge of position, and 
(3) communication of data among undersea sta- 
tions, surface support locations, and onshore 
centers. 
The current approach to undersea mapping 
involves use of surface methods almost exclusively. 
Ocean surveying is limited in accuracy by the lack 
of precise long-range surface positioning systems. 
The advent of satellite positioning constitutes an 
improvement, but does not approach the accuracy 
required to perform undersea construction and 
geological evaluation surveys. 
The same type of basic reference systems 
provided by the usual geodetic methods on land— 
ultimately of comparable accuracy—are required 
undersea for mapping ocean bottom and _ sub- 
bottom features and for recording the location of 
physical, chemical, and biological measurement 
taken in the water column. The technology of 
navigation and bathymetry, mapping magnetic and 
gravitational fields, and primary sub-bottom 
tectonics can be combined to synthesize regional 
geology. 
Technological aspects of ocean surveys cannot 
be considered separately from priorities and types 
of surveys whether they be scientific, industrial, or 
military—each having special requirements. This 
diversity plus the complexity, vastness, and general 
inaccessibility of the ocean volume make surveys, 
especially of the continental shelves and suspected 
anomalies, a first step toward undersea utilization. 
Bathymetric measurement systems have been 
improved markedly in accuracy, speed, and con- 
venience through advancements in echo sounding. 
For detailed studies in deep water, however, 
existing systems are not adequate. Measuring and 
recording profiles of the ocean bottom along 
selected courses traveled by the survey ship, plane, 
or satellite omits knowledge of intervening areas 
that can be compensated only by increasing the 
number of courses (survey lines). 
High endurance submersibles with side-scan 
sonar and short range echo sounders offer a 
method for detailed bathymetric mapping essen- 
tially independent of subsurface visibility and 
surface weather. Major obstacles are the lack of 
precise navigation and limited endurance and 
payload. 
Acoustic profiling with high energy sources, 
mechanical vibrators, air guns, gas exploders, 
electric arcs, and explosives can be used for deep 
reflection and refraction work. Detailed shallow 
water geology can be defined with high resolution 
profiling utilizing low energy sources. 
For several years, general surveys of limited 
ocean areas (as parts of the Gulf Stream) have 
been conducted from aircraft. Some data are being 
gathered on the sea surface now by weather 
satellites, and steps are being taken to establish 
global surveys of the ocean surface by satellite 
(Figure 1). Aircraft and satellite mounted cameras, 
infrared radiometers, microwave radiometers, and 
similar instruments are capable of gathering valu- 
able data on ocean surface temperature, sea state, 
ice conditions, current and water mass movements, 
schools and congregations of fish, phytoplankton 
blooms, water pollution, and other important 
processes. 
b. Future Needs The study of ocean processes 
and marine species on more than a very small scale 
will require the availability of data on an auto- 
matic or rapid retrieval basis. Ocean engineering 
efforts will profit greatly from the existence of 
rapid access to data on the environment. Predic- 
tions of fish production and migration to optimize 
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