TECHNICAL DISCUSSION OF PROPOSAL FOR 'NEEDS ANALYSIS AND SOLUTION ANALYSIS' FOR THE HIGH PRECISION STEREO COMPARATOR

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04770A002900010002-9
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 21
• Document Creation Date: December 28, 2016
• Document Release Date: June 8, 2005
• Sequence Number: 2
• Publication Date: March 1, 1966
• Content Type: STUDY

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Enclosure a
Declass Review by NGA.
March 1, 1966
Technical Discussion of Proposal For
"Needs Analysis and Solution Analysis"
for the
High Precision Stereo Comparator
1. Introductory Statement
Several studies have been conducted of the feasi-
bility of developing a High Precision Stereo Comparator
and of the possible problems to be encountered. The
studies have recommended certain design choices. Prior
to proceeding with detail design, it is desirable to
review the various proposed design choices in the light
of the current needs. Thus, a set of technical specifi-
cations for procurement can be prepared which will be
accurately tailored to the requirements.
2. Needs Analysis
"Needs Analysis" is an engineering design term
which refers to the technique of aggregating and summariz-
ing all the various input requirements, stripping them to
their basic essentials and converting them to an engineering
statement of the problem. It is important that all the
needs be considered and the following sources of needs
will be included:
a.) Operator needs
b.) Maintenance needs
c.) Test and acceptance needs
d.) Measurement precision needs
e.) Measurement rapidity needs
f.) Computer needs
g.) Calibration needs
h.) Procurement (Contracting Officer) needs
i.) Shipping needs
j.) Installation needs
k.) Operator training needs
1.) Maintenance training needs
m.) Manufacturer's needs
n.) Building facilities needs
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2
and others. The needs analysis provides a framework against
which the proposed solutions can be tested.
3. Solution Analysis
The High Precision Stereo Computor can be considered
as a system which receives inputs, performs a transformation
and produces outputs.
Input
Desired
Environmental: -
Transformation
System
Output
---=> Desired
?> Undesired
The purpose of the Solution Analysis is to define a system
which will optimize the output and be physically realizable
and economically realizable. The design paths and design
choices of the study programs are the solutions to be
tested. They will be tested against:
a.) Easy acceptance of desired inputs
b.) Insensitivity to environmental inputs
c.) Maximizing desired outputs
d.) Minimizing undesired outputs
as well as the degree to which they meet the needs.
4. Procedure
The procedure will be to:
a.) Establish the needs by querying the sources
and reducing the needs to quantitative
engineering statements.
b.) Review the study reports to test the
solutions against the needs and define the
system in quantitative engineering terms.
c.) From the engineering statement of the
problem and the system, prepare a set of
specifications which will:
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Approved For Release 2005/06/23 : CIA-RDP78604770A002900010002-9
1.) Describe the Comparator
2.) Define installation requirements,
envirohment and other engineering
input required from Contracting
Officer.
3.) Define the manufacturers output
4.) Define the test and acceptance
standards.
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ApprovedEndRelease_211115ffi6/2.3_:_CIARDMBUMAM2900010002-9
Enclosure b March 1, 1966
Cost Estimate for Proposed
"Needs Analysis and Solution Analysis"
for the
High Precision Stereo Comparator
Work Statement
Perform a needs analysis and review study reports.
Prepare an equipment technical description and a technical
specification of performance and test and acceptance
standards.
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Delivery:
Specification report two months after authorization to
proceed.
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Appro
I.
? - - ? V V ?II
Enclosure c
Compilation of abstracts of
studies relating
to the High Precision Stereo Comparator.
900010002-9
March 1, 1966
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Approved For Release 2005/06/23 : CIA-RDP78604770A002900010002-9
October 30, 1964
Report on Orientation and Briefing Meeting
Subject: High Precision Stereo Comparator
Date & Place: October 15, 1964, at Washington, D.C., facility
of Technical Representative of Contracting
Officer
Attending: Chris M
John R
Jack E-
John S
The development objectives of a new submicron accuracy comparator
were reviewed in considerable detail. The following discussion
presents the conclusions of the meeting and also incorporates
some further comments of my own.
1. GENERAL FEATURES
1.1 High speed measuring to submicron accuracy.
1.2 A general purpose workhorse device with maximum operator
ease (to lessen fatigue) and efficiency (for rapid
measuring capability). -
1.3 A stereo capability with each stage accommodating 25 cm
x 50 cm (10" x 20") formats.
2. MEASURING ENGINE
2.1 The accuracy required over the full 25 cm and 50 cm
travel or any part thereof is one part in 20,000 (with
a design goal of one part in-100,000) or better except
that the highest accuracy required will be + 1/2 micron
(design goal + 1/4 micron) over small travels. See
attached plot of accuracy,required vs. measuring engine
travel. The accuracy stated above refers to total
readout repeatability accuracy and includes electronics
errors, temperature drift, etc. It does not include
operator pointing accuracy. In addition, the engine
ways must be straight and orthogonal to 2 seconds of
arc (9.7 x 10-6 radians),ie, the ways must contribute
less .than 5 microns error to a measurement over 20
inches of travel and less than 2-1/2 microns error to
a measurement over 10 inches of travel.
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Approved For Release 2005/06/23 : CIA-RDP78604770A002900010002-9
November 9, 1964
Preliminary Technical Report
on
Item 1. Submicron Measurement Error Analysis.
Item I Work Statement: Evaluate the physical and
metallurgical properties of materials used in measuring
engine construction to determine comparative suitability
to submicron measuring. Materials to be considered are:
Meehanite, steel, granite, aluminum, magnesium, and
glass.
Submitted by:
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Task II. Item 1. Preliminary Technical Report.
The materials under study are:
1. Meehanite
2. Steel
3. Granite
4. Aluminum
5. Magnesium
6. Glass
The materials may be more precisely defined as follows:
Meehanite. A high quality grey cast iron. The composition
and properties are much more closely controlled than
common structural cast iron. Meehanite is available in
a variety of grades and the properties vary widely with
grade.
Steel. Available in an enormous variety of alloys. For
our purposes a low carbon, wrought, structural steel is
representative.
Granite. Natural quarried granite is available in pink,
grey, and black. Black granite is reportedly the hardest,
most uniform, and best quality so we have used it in the
evaluations.
Aluminum. Tooling plate is specially formulated and
fabricated for high stability and low residual stresses.
The cast type 300 is slightly better than wrought type.
Therefore, the properties of Alcoa type 300 cast aluminum
tool and jig plate have been used in the evaluation.
Magnesium. Dow Alloy AZ 31 B is specially fabricated in
tooling plate with high stability and low residual stresses.
Alloying elements are 17 zinc and 0.45% manganese.
Glass. Fuzed quartz was selected as the glass best suited
to measuring engine applications.
The properties covered in detail in this preliminary
report are:
1. Modulus of elasticity (stiffness).
2. Density (weight).
3. Ratio of stiffness to weight.
4. Thermal conductivity.
5. Thermal coefficient of linear expansion.
6. Thermal capacity.
7. Ratio of? thermal expansion to thermal
capacity.
-1-
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April 30, 1965
2nd Preliminary Technical Report
Item 1. Submicron Measurement Error Analysis
Item 1 Work Statement: Evaluate the physical and metal-
lurgical properties of materials used in measuring engine
construction to determine comparative suitability to
submicron measuring. Materials to be considered are:
Meehanite, steel, granite, aluminum, magnesium, and
glass.
Submitted by:
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Approved For Release 2005/06/23 : CIA-RDP78604770A002900010002-9
2nd Preliminary Technical Report
CONTENTS
1.
Summary
1
2.
High modulus of elasticity material
2
3.
Zero thermal expansion material
3
4.
Comparative desirability
4
5.
Other aspects of dimensional stability
6
6.
Materials cost
8
7.
Conclusion
9
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-1-
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1. Summary
In the first preliminary technical report, dated
November 9, 1964, certain physical and metallurgical
properties were examined to determine which of the
following materials are best suited to measuring engine
construction:
3)
46)
Meehanite cast iron
Structural steel
Black granite
Aluminum tooling plate
Magnesium tooling plate
Fuzed quartz glass,
In subsequent study it was observed that beryllium had
properties superior to steel and that certain special
glasses had zero thermal expansion. It was therefore
decided to include beryllium metal and Cer-Vit C-100
glass in the evaluation. Dimensional stability was the
principal criterion and the thermal stability and
structural rigidity of the materials were considered.
The order of preference was found to be:
a) Thermal dimensional stability
Rank
Index*
(1)
Cer-Vit C-100 glass
0.00
(ideal)
? (2)
Quartz
0.10
(3)
Beryllium
1.00
- (4)
Granite
1.16
(5)
Aluminum
2.08
? (6)
Meehanite
3.74
(7)
Steel
3.86
(8)
Magnesium
4.04
(least
desirable)
b) Structural rigidity per unit weight
1) Beryllium
2) Cer-Vit C-100 glass
3) Steel, aluminum, and
magnesium
--MGranite
Meehanite
6 Quartz
Structural rigidity under external
loads
1
*Rank index is based on beryllium = 1.00
values indicating reduced effectiveness.
Rank Index*
1.00 (most desirable)
4.48
6.23
8.26
9.35
11.35
to 5.17
to 7.15
(least desirable)
Rank Index*
1)
Beryllium
1.00
(most desirable)
2)
Steel
1.45
3L3Meehanite
Cer-Vit C-100
1.83
3.13
to 2.40
5)
Aluminum
4.07
6)
Magnesium
6.46
7)
Quartz
9.55
(least desirable)
with larger
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Approved ror Release 2005/06/23 . CIA-RDP78004770A002300010002-9
June 30, 1965
MATLTNa ADDRESS!
Task II, Item 1, 3rd Preliminary Technical Report
7
Item 1. Submicron Measurement Error Analysis
WORK STATEMENT
Evaluate the physical and metallurgical properties
of materials used in measuring engine construction
to determine comparative suitability to submicron
measuring. Materials to be considered are: Meehanite,
steel, granite, aluminum, magnesium, and glass, and
other materials that may be particularly suitable.
Evaluate physical properties and structural concepts
appropriate to achievement of vibration levels and
structural rigidity compatible with submicron
measuring requirements. Evaluate methods of measuring
the small vibration levels expected in a high
performance structure.
Reports No. 1 and No. 2 dealt with the physical and metal-
lurgical properties of materials. This report, No. 3, deals
with structural rigidity and vibration control.
Submitted by:
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Approved For Release 2005/06/23 : CIA-RDP78604770A002900010002-9
Task II, Item 1, 3rd Preliminary Technical Report
CONTENTS
1. Summary
1.1 Introduction
1.2 Summary of report
1.3 Conclusions and recommendations
2. The major base block
2.1 Composite or homogeneous construction
2.2 Weight and rigidity
2.3 Principal elastic mode of vibration
2.4 Vibration isolation of the block
2.5 Interaction with the floor slab
3. The microscope objective support
3.1 Microscope depth of field
3.2 Some structure criteria
4. The moving platen
4.1 General size and construction consideration
4.2 Air bearing normal transmissibility and pulsation
4.3 Air bearing lateral transmissibility and pulsation
STAT
5. The outer structure
5.1 Some structure criteria
5.2 Vibration isolation of the structure
5.3 Some criteria for the drives, pumps and blowers
6. Detail analysis of the structure following preliminary design
6.1 Analytical approach
6.2 The computer program for structural dynamic analysis
6.3 Isolation system servo loop simulation
7. Methods of measuring structure peeformance
7.1 Floor dynamic environmental data
7.2 Granite damping characteristics
7.3 Tests of critical items
Appendix
Free vibration analysis of 20'x20' floor slab by IBM 7094
computer program
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July 30, 1965
MATT.TNn AnnT21gq.
Task II, Item 1, 4th Preliminary Technical Report
Item 1. Submicron Measurement Error Analysis
WORK STATEMENT
Evaluate the physical and metallurgical properties
of materials used in measuring engine construction
to determine comparative suitability to submicron
measuring. Materials to be considered are: Meehanite,
steel, granite, aluminum, magnesium, and glass, and
other materials that may be particularly suitable.
Evaluate physical properties and structural concepts
appropriate to achievement of vibration levels and
structural rigidity compatible with submicron
measuring requirements. Evaluate methods of measuring
the small vibration levels expected in a high
performance structure.
Reports No. 1 and No. 2 dealt with the physical and metal-
lurgical properties of materials. Report No. 3 dealt
with structural rigidity and vibration control of the
machine structure. This report, No. 4, presents results
of a computer analysis of building floor vibration
frequency.
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STAT
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-1-
1. SUMMARY
A free vibration analysis of one typical bay of an
upper story floor of a building has been made. The floor
is a multiple bay slab-column structure. The purpose of
the analysis was to determine the fundamental and higher
mode frequencies of the floor slab. Knowledge of the
floor frequencies is important to determine the inter-
action of floor with the vibration isolation system of
a projected submicron measuring machine.
The assumed floor structural dynamic model is shown
in Figure la and lb. The analysis was carried out by an
existing IBM 7094 routine. The result of the computation
indicates the fundamental frequency is 15.6 cycles per
second. If the data on the floor construction is accurate
the analysis will yield a 107 accurate fundamental fre-
quency. The fundamental frequency may therefore vary from
14 to 17 cps. The computed 15.6 cps. fundamental floor
frequency is much lower than the 20 cps. to 65 cps. anti-
cipated in report No. 3. If the floor frequency is that
low, it would necessitate a machine vibration isolator
system of much lower natural frequency than the 8 cps.
suggested in report No. 3.
Before proceding further on the structure evaluation,
the floor frequencies will be reexamined with more accurate
data on the floor construction.
2. STRUCTURAL DYNAMIC MODEL OF THE FLOOR SLAB
Figure la shows the grid framework of the floor slab.
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Approved For Release 2005/06/23 : CIA-RDP78604770A002900010002-9
September 30, 1965
Mailing Address
Task II - Item 1 Submicron Measurement Error Analysis
Comments on some Vibration Measurements
WORK STATEMENT
Evaluate the physical and metallurgical properties
of materials used in measuring engine construction
to determine comparative suitability to submicron
measuring. Materials to be considered are:
Meehanite, steel, granite, aluminum, magnesium, and
glass, and other materials that may be particularly
suitable.
Evaluate physical properties and structural concepts
appropriate to achievement of vibration levels and
structural rigidity compatible with submicron
measuring requirements. Evaluate methods of measur-
ing the small vibration levels expected in a high
performance structure.
Reports No. 1 and No. 2 dealt with the physical and metal-
lurgical properties of materials. Report No. 3 dealt with
structural rigidity and vibration control of the machine
structure. Report No. 4 presented results of a computer
analysis of building floor vibration frequency. This
technical note contains comments on building floor vibration
measurements.
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Technical Note on Building Floor Vibration Measurements
In technical report no. 4, dated July 30, 1965, the
results were presented of a computer analysis of the free-
vibration mode of a typical bay in the building in which the
submicron measuring instrument will be used. The computer
analysis indicated that the fundamental mode of the floor
slab vibration was 15.6 cps. This is considerably lower than
the 20 cps to 65 cps previously estimated from manual calcula-
tions. The lower floor slab frequency makes it much more
difficult to achieve effective vibration isolation between the
floor slab and the measuring instrument. Whereas we had
previously believed that an 8 cps mount would be satisfactory
(for floor frequencies of 30 cps and higher), it now appears
that a 2 cps mount is necessary for 15 cps input from the
floor. Fig. 1 illustrates the greater ?effectiveness of a
2 cps mount.
An attempt was made to detect floor slab resonant
frequencies but results were questionable. During the day
we were not able to excite the floor slab above the back-
ground level. A test was made in the early morning when the
background level was low and 30 cps, 60 cps and 90 cps was
detected. The results are suspect because we could not be
assured that we were not measuring stray voltages from the
60 cps building power.
A report on Bureau of Standards floor vibration measure-
ments made in 1960 was reviewed. The report indicated that
on the second floor, the vertical component could go as low
as 5 to 7 cps and horizontal components as law as 3 to 5 cps.
Effective isolation of frequencies that low is hopeless.
In fact we hesitate to recommend a mount as soft as 2 cps.
A mount suspended on vibration isolators that soft is awkward
for an operator to work on because small forces create large
excursions. For an 8 cps mount the lg excursion is only 0.165
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February 1, 1966
Task II Item 8 Technical Report
LASER METROLOGY
Work Statement: Investigate the use of the
helium neon gas laser for measuring engine
applications. The use of a laser interferometer
and fringe counting for measuring length has
problems with counting rate and with vibration
and thermal gradients interfering with counting.
There are certain precautions which must be
taken.
This report presents an analysis of the magnitude of
potential errors in applying a laser interferometer to a
high precision measuring engine.
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STAT
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Approved For Release 2005/06/23 : CIA-RDP78604770A002900010002-9
-1-
1. INTRODUCTION
1.1 Summary
An analytical investigation was made of the problems
associated with use of an interferometer for precision measure-
ment of length. The investigation was oriented toward the
usage of the helium-neon gas laser for the interferometer light
source. The precision criterion was the measurement of lengths
up to 1 meter to an accuracy of k micron. Interferometers
have been used for many years for the precise measurement of
short lengths. Pre-laser light sources permitted precise measure-
ment of lengths up to about 10 cm. Laser light sources permit
precise measurement of lengths of at least several meters and
perhaps several hundred meters.
Quantitive estimates are presented in this report
of the effect on the precision of measurement of: wavelength
determination, mirror alignment, atmospheric variations, parti-
cles in the beam, traversing speed, polarization, spectral
purity and vibration. Spectral purity (i.e? spatial coherence)
and mirror alignment are of paramount importance. Only traversing
speed presents unresolved problems and vibration of course re-
quires special analysis of detail structure.
The classic Michelson arrangement with minor
modifications has proved most practical for metrology. The
Fabry-Perot arrangement is well suited only to the measurement
of a fixed length.
1.2 Conclusions
There is no doubt as to the technical feasibility
of using a helium-neon gas laser interferometer to make
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