(UNTITLED)

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04747A002700030045-1
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 13
• Document Creation Date: December 28, 2016
• Document Release Date: August 2, 2002
• Sequence Number: 45
• Content Type: REQ

Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
I
t
The only settings required of the operator is a zero reset
button and a magnitude of accuracy setting knob determining the
operating range.
Figure 1,
Linear measurement. The measuring interferometer with
precision optical components produces optical fringes developed by
an internal light source, Counting a number of fringes determines
distance traveled. The wavelength used is produced by a Hg-198
light source with a filtered frequency of 5461 Angstroms.
The stability of measurement with the
STAT
STAT
DIGITIZER is STAT
assured by unique method of mounting the optics that do not require
adjustment after extended usage. A split phase, three photomultiplier
detection gives highly accurate reversible sensing of fringes,
independent of reasonable variation of input voltage environmental
conditions ,anti time of operation.
For operation the sensor is nornally stationary mounted.
The travelling tetrahedral prism is mounted on the moving body
whose location it is desired to determine. As the body moves, light
wave fringes are formed and are counted, between the tetrahedral
prism and the sensor representing its exact displacement to a
repeatable accuracy.
Declass Review by NIMA / DoD
I Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
-2-
 Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
Controls and Counter:
Automatic optical fringe counting is achieved by a novel
(patent applied for) detection scheme using three photomultipliers.
The ~owbination of optics and electronics assures that accurate
u asturement are obtained independent of vibrations or overshoot of
th measured table. A numerical unambiguous output is developed
in a visible counter display,
The counter can be provided with a standard accessory of
4 tine BCD readout for use for automatic readout, on punch tape,
punch card or ma..jnetic tape. A manual preset counter as an
accessory will allow the operation of the
STAT
STAT
a closed loop servo. Accessory digital circuits are available for
operation of the automatic control from a storage medium such as
a Flexowriter or magnetic tape or drum.
The control box and counter are made of several plug-in
packages and interchangeable circuit boards, tested for stability
and? re1.iiahi.- ity.
STAT The I IDIGITIZER is universal system developed to
measure either distance or angles. Angular rates or linear rates
over time may also be measured to an unprecedented accuracy. The
saJiie controls and counter are utilized, the only difference being
the optic..:. configuration of the interferometer.
Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
-
 Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
STAT
Automatic Linear Interferometer:
Figure 1 illustrates the general configuration for linear
STAT
Each count on the digitizer can be
selected to measure in either of the following:
1. 0.273 microns or 10.8 millionths of an inch.
2, 0.136 microns or 5.4 millionths of an inch.
3. 0.068 microns or 2.7 millionths of an inch.
4. 0.023 micron or 0.9 of one millionth of an inch.
Three models are provided with successive increase in cost:
1. Total Range + l
2. Total Range + 511
3. Total Range 1 meter (Special Type).
A major feature of the
ability to measure the distance between
DIGITIZER is its inherent STAT
two points to an unprecedented
accuracy independent of the accuracy of the guide ways of the
measured member providing they are vibration free. Thus, + .0Ol.,in.
out of straightness can be tolerated in the Y and Z axes providing
that the stability of the ways is established. Skewing errors of
a few minutes of arc can also be tolerated.
To enhance the use of the
has developed patented mechanical ways adaptable to linear measuring
tables and various types of test equipment.
Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
STAT
STAT
 Approved For Release 2002/08/20 : CIA-RDP78B04747A002700030045-1
ISTAT
DIGITIZER for Angular Measurement:
STAT
Figure 2 illustrates the general configuration for angular
STAT measurement
Each count on the digitizer will measure
angles to an accuracy of .05 second of arc for a range of 10.
With the application of a timing device the Model
I
measure angular rate to an accuracy of .05 second.
will STAT
This instrument n asures the relative angular orientation of
a table or other devices such as gyros or stabilized platform
guidance systems, The sensing package is located to observe two
returning light beams generated by a light source within the
interferometer. An optical block containing two tetrahedral prisms
is mounted on the table or object being calibrated. Consequently,
as the table rotates, one return optical path is decreased or in-
creased relative to the other, allowing the fringes to change.
The generated angle is measured by the number of wavelengths of
light that constitute the difference of path lengths. The exact
angle to an accuracy of .05 second of arc is read on the Digitizer
due to the inherent stability of light wave measurement.
Approved For Release 2002/08/20 : CIA-RDP78B04747A002700030045-1
 Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
t
2
STAT
in the
anall as 0.27, or larger than one meter. CONSEQUENTLY w THE
STAT
DIGITIZER for Angular measurement are available
following standard packages:
1.0 second per division.
0.5 second per division.
0.2 second per division.
0.1 second per division,
0.05 second per division,
0.02 second per division (on special order).
A range of measurement up to 50 1s obtained. The linear
distance between the rotating member and the sensor can be as
STAT
Digitizer WILL REPLACE AUTOCOLLIMATORS WITH A CONSIDERABLE INCREASE
OF ACCURACY AND RANGE.
Angular Rate Automatic Interferometer;
Angular
rate. The accessory is a
DIGITIZER
precision
electronic
STAT
will measure angular
a
-
V 1111e
standard, The counter measures the total
angular motion per unit
time. It can be adjusted from a fraction of a second to few
minutes of time. The counter displays the total, angular motion
within preselected unit of time.
The accuracy of the +4__ 4____
_
is
ws-
part in io '", while the accuracy of the
is better than .05 second of arc,
pIGITIZER
STAT
Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
 Approved For Release 2002/08/20 : CIA-RDP78B04747A002700030045-1
STAT
I STAT
STAT
ISTAT
Angular Generator:
Figure 3,
STAT
DIGITIZER with Micro-Positioner,
;haws this angle generator containing the time-proven
Micro-Positioner. Angles are measured as described
kIGITIZER for angular measurement. The Micro-
Positioner contains a mirror or a porro prism rotating about a
vertical axis manually or auto.;a.Atically. The angular deviations of
the mirror or porro prism is
IGITIZER,
measured by the standard angular
The standard system provides manual angular rotation with a
tota _ range of J-6.7 minutes of arc, and accuracy of 0.05 second
over the ful' ran e A~
ces
Jories are available for control of the
angular generator from a remote preset counter, or from punched tape.
Extended ranges up to 50 are available.
Size and Weight:
Measuring interferometer: 12" x 8-3/4" x 5-3/4" high.
Controls and Counter:
Standard Rack: 12" high x 19" wiae x 15" deep - 45 pounds.
Cabinet: 14f" high x 18" wide x 18" deep - 75 pounds.
Power requirement: 115 volts - 60 cps -_2 amperes.
I Approved For Release 2002/08/20 : CIA-RDP78B04747A002700030045-1
 Approved For Release 2002/08/20 : CIA-RDP78B04747A002700030045-1
STAT
This exciting development opens the door to new concepts
of measurement of an unprecedented accuracy of angular and linear
measurement
Your inquiries for its applications to your problems are
invited. There is an application of this device to every phase of
industry from optics - Metrology - Chemistry - Electronics.
Approved For Release 2002/08/20 : CIA-RDP78B04747A002700030045-1
 0
STAT
STAT
1/IvfA,R /yfASI/ ~ ANT
Approved For Relea ~72 p8/20 : CIA-RDP78BO47
S//Y- /ES 7-0 / 24' BETTER.
// ? 7Eq a.Y s~ -ciq~
~S.S/r~NMENT,
STAT
 a
STAT
STAT
f/c' 2
Approved For Release 2002/08/20: CIA-RDP7
STAT
 Wr7
App Fji- Release 2002/08/20: CIA-RDP78BO4747A00
STAT
STAT
 Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
LINE.`.lt U TERFEROMETER
The optical arrangement o:: the linear interferometer is
shown in Figure 1. monochromatic light source', ( ) is used
with an aperture (is). The illumination is collimated by lens
(L1) and is directed onto the beam splitter (_~), it is then
separated in two parts: (1) to a tetrahedral prism C1, which
is then reflected )ack to G;;, at ,.;hick a portion is reilecteci
tea the lens L2; an(' (i i) to the compensati.nee plate E and. then
to a tetrahedral pri_sr: (C,) hack. to E, G, and then tc; the lens,
L2.
The interferometer is friricac s are :t orn ed l v the inter acti on
of the paths (1) ar,n (II) such that the amplitude seen
at (L2) can be the sum;nati_on 01- the illumination through (I) or
(II) as a maximum, and their difference as a m:inimuru. Thus,
if one would move the tetrahedral prism C2 at a constant speed,
then the amplitude observed is approximately sinusoidal in
nature. '1 hce illumination passed by the aperture (B) is then
modulated by the .relative motion of prism C2 to C1. Th is
motion is not dependent on the angular orientation of CI or C2,
since the tetrahedral prisms return the beam pparellel to itself
independent of its an.aeular orientation, In addition, the linear
displacements in axis otl,c than ti,at in linE.: with the light
path introduce no error. as long as they are -,,.(.-.ss than
STAT
Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
-1-
 Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
In this manner, the interferometer measures only linear distance STAT
in line with the light path, which is independent of other angular
or linear displacements.
Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
 Approved For Release 2002/08/20 : CIA-RDP78BO4747AO02700030045-1
STAT
A = Light Source
B = Aperture
C1 and C2 - Corner Cubes
F1, F2, and F3 = Photomultipliers
G = Beam Splitters
B = Compensator
L1 = Collimating Lens
L2 = Focusing Lens F3
X1 = Corner Cube Mounting Block
X2 = Interferometer Mount.
Ml, M2 = Front Surface Mirrors.
Approved For Rele?sien Q0i2/ Rlirul(
r lA r oDP t 8B04747A002700030045-1