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Laser Mythology
CSC 1992
SUBJECT AREA C4
			EXECUTIVE SUMMARY
Title:  Laser Mythology
Author:  Major Roger D. Atkins, United States Marine Corps
Thesis:  There are too many Marines that do not fully understand
current Marine Corps laser systems and how to best employ them to
increase the combat  power of the MAGTF.
Background:  The United States Marine Corps has invested tremendous
amounts of money in laser systems for use on the battlefield.
Science fiction writings, movies, and all to real science projects
like the Strategic Defense Initiative have created myths about
lasers.  Very few Marines fully understand the capabilites of
current battlefield lasers and how to plan for their employment.
Recommendation:  The United States Marine Corps needs to better
educate  Marines  on  the  capabilites,  hazards,  and  planning
considerations for employment of lasers.
		LASER  MYTHOLOGY
			OUTLINE
Thesis Statement.  There are too many Marines that do not fully
understand current Marine Corps laser systems and how to best
employ them to increase the combat power of the MAGTF.
I.   	What comes to people's minds when they think of lasers.
II.  	Capabilities
     	A.  	Designating for precision guided munitions
     	B.  	Observer and target location
     	C.  	Marking targets for close air support
III. 	Hazards
     	A.  	Eye hazards
     	B.  	Designator becoming a target
     	C.  	Backscatter
     	D.  	Prohibited Designator Zone
IV.  	Training considerations and ranges
     	A.  	Laser ranges
     	B.  	MELIOS
     	C.  	HGSS
V.   	Planning considerations
     	A.  	Copperhead Coverage Templates
     	B.  	Copperhead Footprint Templates
     	C.  	Pulse Repetition Codes
                                              Major Roger D. Atkins
                                              Conference Group 1
		LASER MYTHOLOGY
     	Man has been enthralled by the destructive potential
of focused beams of light for many years.  Perhaps the first
description of a beam weapon used in battle comes from the Roman
siege of Syracuse in 212 B. C.
     	Ancient sources say that Archimedes devised a hexagonal
     	mirror, and at an appropriate distance from it set small
     	quadrangular mirrors of the same type, which could be adjusted
     	by metal plates and small hinges.  This contrivance he set to
     	catch the full rays of the sun at noon,  both summer and
     	winter, and eventually by reflection of the sun's rays in
     	this, a fearsome firey heat was kindled in the barges, and
     	from the distance of an arrow's flight he reduced them to
     	ashes.(1: 17)
     	Mention lasers and this picture of ships being incinerated is
what comes to many peoples' minds.  Science fiction writings,
movies and all to real science projects like the Strategic Defense
Initiative continue to reinforce this picture.  Unfortunately this
has created many myths in people's minds concerning lasers,
especially those in use on today's battlefield.  There are too many
Marines that do not fully understand current Marine Corps laser
systems and how to best employ them to increase the combat power of
the MAGTF.  It is time to separate myth from reality so that these
systems can achieve their full potential.
MYTH ONE ( Lasers are only useful in killing tanks and point targets.)
     	It is doubtful that a portable battlefield laser that can
kill a tank all by itself will ever appear in our career.  The
problems of power and fire control are just too difficult.  The war
in South West Asia highly publicized one use of the laser, the
designation of targets for attack by precision guided munitions.
I do not wish to demean this capability, since when properly
employed a laser designator gives the maneuver commander a three to
five thousand meter anti-tank system that has no visual firing
signature.  However, this is not how lasers were first used in the
military nor their primary use.  The first operational use of
lasers was as battle field range finders.  Today this is still
their most important and useful function.  This allows first round
hits from modern fighting vehicles and more importantly more lethal
fires from a forward observer.  It allows a maneuver commander to
direct the attack of targets with "dumb" iron bombs and projectiles
with an unprecedented degree of accuracy.
     	Let's use forward observers as an example.  Forward observers
are just one part of a field artillery team.  This team is made up
of the forward observer, the fire direction center, and the guns.
The team's sole function is to provide accurate and timely fires in
support of a maneuver commander.  Unfortunately the weakest member
of this team has been the forward observer.  No matter how
sophisticated we made our fire direction computers, or precise our
guns we could not eliminate the human error that is caused by the
forward observers inability to always accurately locate a target.
     	The "Army Training Study-Forward Observer" in October
     	1978 evaluated 124 FOs, officer and enlisted, from  nine
    	battalions at Fort Carson and Fort Hood to determine
     	their ability to locate themselves and locate targets
     	and correlated this to their unit training in observed
     	fire.  On the average, the FOs could not meet standards
     	or target or self location.  The target location errors
     	ranged from 400 to 700 meters, and self location errors
     	were from 300 to 400 meters.(2: 55)
     	The laser range finder designator (LRDM) has given the forward
observer the ability to accurately locate himself or a target
within 10 meters.  This translates into more accurate and
responsive fires to a maneuver commander and saves ammunition that
would be wasted on lengthy adjustments.  It also allows the
placement of "dumb" high explosive projectiles in more select and
lethal points within a target array.
    	Another use for the laser on the battlefield is to mark
targets for close air support aircraft.  Traditionally an aircraft
or indirect fire weapon system would deliver a white phosphorus
round as close to the target as possible in order to help identify
the target to attacking aircraft.  Unfortunately, these marking
rounds could be as much as 300 to 500 meters away from the target
and of little assistance to the pilot.  With a laser designator and
an aircraft equipped with a laser spot tracker (LST), or system
that can see laser energy, the forward air controller can
illuminate the target with laser energy which can be picked up by
the attacking aircraft once again making the delivery of "dumb"
iron bombs more accurate.
     	Laser designators were used in South West Asia to mark targets
for close air support.  Some missions were successful, some were
not.  A consideration to be kept in the back of the mind of all
commanders and lasers users is that the laser beam spreads as it
travels down range.  That pencil sized beam that leaves the laser
is approximately 5 feet in diameter at 8 kilometers.  An operator
will have to aim lower on the target than usual to prevent laser
"spill over."  Even with "spill-over" and "underspill" the laser is
still more accurate than the 500 meter WP mark.  Another
consideration is that laser beams can be disrupted by smoke, fog,
or haze.  Just because you can see it through your thermals or
optics doesn't guarantee that you can lase it.(7: 41-42)
MYTH TWO (Laser range finders and designators can burn cloth, skin,
	        and flammable materials.)
     	Ground laser range finders and designators are not harmful to
skin or flammable materials.  However, lasers of all types are very
hazardous to the human eye and the designators themselves can
become targets when precision guided munitions are not properly
employed.
     	The human eye is very susceptible to laser energy.  This
damage is caused by the cornea or eye lens transmitting the energy
onto the retina of the eye.  This damage can vary from flash-
blindness, which is temporary, to hemographic lesions which can
result in total blindness.   The principle dangers to the eye
result from looking directly back at the laser, and from
reflections off mirror like reflectors.  Binoculars and similar
optical devices can increase the hazards.  This optical hazard can
exist as far away as 80 kilometers from the laser.  Ballistic laser
eye protection glasses, visors, binoculars with laser filters
(such as the M22) can reduce these hazards. (4: 56)
    	Precision guided munitions can pose a threat to the designator
when the angle formed between the designator to the target and the
delivery system to target exceeds sixty degrees.  Precision guided
munitions guide on laser energy reflected back from the target into
the field of view of the optical seeker.  Because of the highly
directional nature of the beam, the seeker does not see the beam
itself but only those rays of the beam that are reflected off the
target.  Unfortunately as the beam passes through the lenses of the
designator a small amount of laser energy is reflected giving the
designator a glow or aurora.  If the angle between the designator
and the munition in relation to the target exceeds sixty degrees
the laser spot on the target can become masked so that very little
of the reflected laser energy is being picked up by the seeker.
Also, at these large angles the designator can come into the field
of view of the seeker.  With little or no reflected energy being
picked up by the designator from the target  and the designator
coming into its field of view the seeker will attempt to guide the
munition to the strongest source of reflected energy which is now
the designator.
     	The second hazard is caused by a phenomena known as
backscatter.  If the line of sight between the laser and the target
is not cleared of grass, bushes or trees some of the laser energy
can be reflected off these objects.  This will cause a "spot" short
of the target upon which the laser seeker can guide.  This is
especially hazardous when designator is on the line between the
delivery system and the target.  This can cause the munition to
land short and endanger the designator.  Joint Pub 3-09.1, Joint
Laser Designation Procedures, addresses this area between the
delivery system and the target under Hellfire safety
considerations.  Labeled a "prohibited designator zone", no
designators are allowed in this zone due to the possibility of the
missle tracking backscatter energy.
     	All these hazards can be avoided.  There must be close
coordination between the delivery system and the designator so that
the angle between the designator and the delivery system does not
exceed sixty degrees.  Designators should not be in the prohibited
designator zone, and the line of sight between the designator and
the target area must be cleared of all possible obstructions.  Even
a few blades of grass can be hazardous to your health.
MYTH THREE ( Lasers are more dangerous than other weapons and thus
                        laser safe ranges are harder to build.)
A laser range finder designator is a direct fire weapon system
with an eye hazard range in excess of eighty kilometers.  Lasers,
like a rifle or a pistol, must be respected.  In 1990 the United
States Army issued a message that stated soldiers should not look
in the firing port or "business" end of a laser while pressing the
firing button.  This is equivalent to saying you should not hold a
pistol to your head while pulling the trigger.  This may sound
humorous, but unfortunately the message was the result of soldiers
in two separate instances injuring their eyes by looking in the
laser firing port of a laser range finder and pulling the trigger.
Laser firing ranges are very similar to any other direct fire
weapon range.  It contains a buffer zone to prevent inadvertent
lasing of targets that might lie outside the safety fan and a
backstop to catch any stray laser energy that might miss the
target.  Procedures for the construction of laser safe ranges and
the duties of the laser range safety officer are contained in Army
Regulations 385-63, Chapter 19 and Army Regulations 385-30. (6:
16-19)
     	There are two new developments that might one day allow us to
operate lasers without the restrictions of ranges.   HGSS, 
Hellfire Ground Support System, and MELIOS, Miniature Eyesafe Laser
Infrared Observation Set, are  two new systems being fielded by
the United States Army that will greatly reduce laser safety
hazards in peacetime and combat.
     	HGSS was designed to help train designator operators to track
moving and stationary targets.  This system consists of an eyesafe
laser designator, approximately the same size and physical
characteristics as a real designator, and a sensor array that can
be put on any vehicle.  Once installed the operator can then
practice tracking the vehicle and illuminating the sensors.  The
use of actual combat vehicles lends realism to the exercise.  This
system was used in South West Asia for training.  One division,
which successfully destroyed 9 out of 10 targets with cannon
launched laser guided projectiles, credited its success with PGM's
to this system.
     	MELIOS is a replacement system for the AN/GVS-5 laser range
finder.  Utilizing a Raman-shifted Nd:YAG laser and blocking filter
this system will provide an eye safe laser for use in peace time
and combat.  Application across the spectrum of laser range
finders and designators will significantly enhance training and
reduce the need for laser ranges.(3: 174)
MYTH FOUR (Laser guided weapons are simple to employ and always hit
                     the target)
     	Many people think that laser guided weapons are silver
bullets.  They like to believe that they are simple to employ and
always hit the target.  When they don't live up to these
expectations people lose faith in them.  The 155 mm cannon launched
laser guided projectile (COPPERHEAD)  was one such weapon system.
When developed it advertised a 90% probability of kill.  After
fielding this probability of kill based on rounds fired in support
of unit training went down to around 60%.  Because of this
"perceived" reduced accuracy, procedures were established to fire
two rounds at each target in order to ensure its destruction.
Recently it has been discovered that the inaccuracies or low
probability of kill was not from the weapon system, but from poor
planning.
     	Prior planning for the use of laser guided munitions is
critical to their success.  This planning must take into account
the position of the designator in relation to the delivery system,
for both accuracy and safety, the size of the area which the seeker
can see and make course corrections, and the proper proper pulse
repetition frequency for the designator and seeker. There are two
templates that assist in planning laser engagement area for the
observer.
     	The Copperhead Coverage Template has been designed as
a position selection aid to be used by fire support coordinators in
selection of forward observer locations when using cannon launched
laser guided projectiles.  It is a tool that rapidly discriminates
between can shoot and can't shoot engagement areas.  Aircraft can
easily change positions when the firing angle is unsuitable for
accuracy or safety.  Cannon units cannot.  This template is based
on experience that has shown that target engagement angles between
the designator and firing unit that exceed 45 degrees adversely
affect accuracy and that the maximum effective range for designator
operators is 3 kilometers for moving targets and 5 kilometers for
stationary targets.  Procedures for use of this device are
contained in FM 6-20-40, Fire Support For Brigade Operations Heavy.
When properly used this device can determine the best position for
designators, which firing assets best support them, and whether an
designator or firing unit must be relocated. (5: 26)
     	The Copperhead Footprint Template is used to help select
adjusting points within the engagement area designed by the
Copperhead coverage template.  On the downward leg of the
Copperhead flight, the round acquires the reflected laser energy
and begins to guide on the target. This area in which the seeker
can acquire and guide is limited.  This oval shaped area is called
a footprint.  Although the round can maneuver to the outside area
of the footprint, the greatest chance of hitting the target is when
it is near the center of the footprint. Copperhead Footprint
Templates were developed to accurately portray this footprint or
engagement area around each adjusting point.  Copperhead M712,TE 6-
6-1, NSN 1220-01-224-2588 contains 12 templates numbered A-L which
are designed based on target cloud height, the gun target range,
visibility, and angle of fire (high or low).  Procedures
for the use of these templates is contained in FM 6-30, Observed
Fire.  When used by fire support coordinators and designator
operators these templates can greatly increase the missions chance
of success.  (6: 22-24)
     	Though there are no tools to assist the planner, a very
important consideration is the pulse repetition frequency code.
Laser designators and use a pulse coding system to ensure that a
specific seeker and designator combination work in harmony.  (4:
1)  The planner must be concerned with the limited number of codes
available, their allocation, assignment, and characteristics.
     	Laser codes, depending on the equipment, are either three
digits or four digits.  If it is a four digit code the first digit
is always the numeral 1.  The laser codes vary from 111-488
(Band 2) to 511-788 (Band 1).  These numbers represent the nano-
seconds of delay between the laser pulses.  The smaller the number,
the smaller the delay.  The result is that band 2 pulse rates
result in more laser energy striking and reflecting off the target
giving the seeker a better laser spot to guide on.  As a result
band 2 pulse rates are better for adverse conditions and when the
mission has a high priority.  If you throw in the fact that there
are only six hundred and seventy-seven codes available (788-
111=677) on any given day to U.S. forces, you soon see that
priorities should be set for the distribution of these codes.
This is where allocation and assignment becomes important.  In
a MAGTF the senior fire support coordination center (FSCC)
allocates different blocks of codes to artillery ,air ,and naval
gunfire assets.  The FSCC will also keep a block of codes for MAGTF
special use.   Fire support coordinators in subordinate units not
only coordinate codes with adjacent units, they monitor missions
and ensure proper code coordination between the delivery unit and
the designator.  Normally the delivery system will tell the
designator which code to use.  There may be occasions where a
special code for that mission is assigned to the designator and
delivery system from the block reserved by the MAGTF FSCC.
     	All pulse repetition codes can the used for laser designation.
However, the characteristics of band 2 codes make them more
suitable when designating for laser guided munitions. (4: 1-3)
CONCLUSION
       	The United States Marine Corps has invested tremendous
amounts of money in laser systems, both air and ground.  There are
too many Marines that do not fully understand Marine Corps laser
systems and how to best employ them to increase the combat power of
the MAGTF.  The myths generated by science fiction tend to cloud
the facts of reality.  A great deal of this mis-understanding is
due to a lack of training and education.  Lasers are considered to
difficult and ranges to operate them to hard to build.  This just
is not so.  Treated with the respect given any other direct fire
weapon system they can be used safely.  They are not silver bullets,
but require planning to successfully employ them.  Used properly
they can give a maneuver commander the capability to surgically
shape the battlefield, or silently assinate an unsuspecting
commander.  The United States Marine Corps is laser equipped.  It
is time we became laser capable.
                                 BIBLIOGRAPHY
1.  Hecht, Jeff.  Beam Weapons.  Plenum Press. 1984.
2.  Kelly, Michael, B..  "Why FO's Can't Shoot."  The Field Artillery 
Journal.  (July 1979) 54-56.
3.  Ogorkiewicz, R. M. . "Eye Safe Neodymium Lasers."  International Defense
Review 2.  (1990) 174-175.
4.  The Jiont Chiefs of Staff.  Joint Laser Designator Procedures. Joint
Pub 3-09.1, (1 June 1991) Chapter IV-V.
5.  United States Army.  Headquaters Department of the Army.  Fire Support 
for Brigade Operations (Heavy).  FM 6-20-40, (January 1991) Appendix H.
6.  United States Army.  Headquarters Department of the Army. Observed Fire.
FM 6-30, (29 April 1991)  Appendix A.
7.  Ursey, Floyd, J. Jr. Maj, USMC.  "Marking the Battlefield for Close Air
Support."  Marine Corps Gazette.  (February 1992) 39-42.



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