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Understanding Urban Terrain. Six Fundamental Differences. Decentralized Control Communications are frequently restricted and intermittent Requires centralized planning and focus Presence of a civilian population Is always a factor Uneven ambient light Glaring lights and harsh shadows - PowerPoint PPT Presentation
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UnderstandingUrban Terrain
Six Fundamental Differences1. Defensive Advantage• Defender enjoys cover and
concealment• Avenues of approach are highly
predictable
2. Three-Dimensional• Buildings are hollow and multi-story• Some buildings have intrinsic value• Vertical avenues of approach and
escape
3. Short-range engagements• Typical engagement is less than seven
yards• Targets are fleeting and line of sight is
restricted
4. Decentralized Control• Communications are frequently
restricted and intermittent• Requires centralized planning and
focus
5. Presence of a civilian population
• Is always a factor
6. Uneven ambient light• Glaring lights and harsh shadows• Many surfaces are highly reflective• Night vision nearly impossible
Understanding Urban TerrainPublic Land Survey System• Originated by Thomas Jefferson
in 1785• Includes private land that has
been sold• >1.5 billion acres have been
surveyed• Used to divide public lands into
rectangles• Townships—6 square miles• Sections—1 square mile
(640 acres)• Subdivisions—anything less than a
section• Half section, quarter section,
quarter-quarter section, etc.
1 Mile(640 Acres)
Understanding Urban TerrainCity Streets
~1/8th Mile
Base line
Rang
e lin
e
Conventions• Street numbers
• Odd—north and west• Even—south and east
• Base line• Central or Center• Main• Midway
• Range line• Meridian• Principal
100E→←100W
100N
→←
100S
200E→
Sociological Influences• Age
• The 100 year old house is an anomaly. The "lifespan" for houses is ~73 years
• 43+% have been built since 1970 and about 70% of the 110 million houses in the USA will be around at least another twenty years
• Family• Size and idea of
family has impactedsize and construction
• Societal shifts• Agriculture to industry
to information• Crime, congestion, safety
(reversed floor plans)
Technological Influences• Construction materials
• Plywood, trusses, metal reinforcements, drywall, pre-hung doors, plastic pipes, zero clearance fireplaces, central air conditioning, manufactured housing
• Accessories• Fiber optics, HD TV, intercoms, dishwashers, trash compactors, wireless
internet, multiple phones, whole house audio, etc.• Multiple bathrooms and
home office now common• Anti-intrusion systems
• Floor plans changedto accommodate newtechnologies and life styles
Economical Influences• House is single most expensive lifetime investment
• House representsperson's "worth"
• Great Depression• Smaller houses,
row houses andtract housing
• Post World War II Boom• Converted row houses, large scale tracts, mass-produced housing
• Similar, even identical floor plans
• Today• Cottage industries, telecommuting, electronic access• Home offices now becoming a norm
Political Influences• Building Codes• First appeared in 1922• Governs types of construction
• Planning and Zoning Ordinances• Four major zones
• Residential, industrial,commercial and agricultural
• Divided still further into types of each• Results in clusters of
types of buildings• Adjacent attributes often
apply to target
Environmental Influences• Every house is a "mini-environment" (climate)
• Conditioned air, water storage and drainage, protection from elements, etc.
• Fire• Protection is paramount • Primary impetus for building codes
• Water• Protection from precipitation• Protection from ground water• Water kept inside for drinking
washing, eating, cooking, etc.• Wind
• Affects building codes and design• Gravity
• The ubiquitous force to which all buildings eventually succumb• Strongly influences construction and provides reliable clues for floor
plans— especially weight over distance (span)
Multi-Story
Number System
2
3
4
Front side is “1 Side”
Single Story
41
A
B
C
D
E
1 2 3
1 2 3
1 2 3
1 2 3
1 2 3
Left to RightBottom to Top
Immediate Deployments
“Rear Five”
“Front Five”
1
Cardinal Directions (most well known)Awkward in city, compasses affected by magnetic fields and steel objects
Shift from a known point (common)Uses prominent terrain features as steering marksRequires prior knowledge or detailed directions
Grid System (MGRS, Thomas Guide and others)
Effective over distance but requires map and ineffective for micro-terrain
Numbering System (Common tactical “work around”)
Highly effective for micro-terrain, inappropriate for longer distances
NAVIGATION
Questions?