LINEAR PHASOLVER MEASURING ENGINE

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04770A001500070007-3
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 4
• Document Creation Date: December 28, 2016
• Document Release Date: June 28, 2005
• Sequence Number: 7
• Publication Date: April 30, 1965
• Content Type: REPORT

STAT
STAT
Approved For Release 2005/07/13 : CIA-RDP781304770A001500070007-3
April 30, 1965
PkOV 40 WINE
phasolver is an adaptation of the vtarv phasolver.
hasolver is a standard product of thel I STAT
which measures shaft angles to a very high ad,- racy,
It is used for remote measuring of radar antenn3
ition, theodolite pointing direction and the
phasolver uses the same principles as true
phaeolveibut for measuring linear dimensions to sab.
accuracy.
STAT About two years ago, foresaw the need for 3
new measuring engine, but he did not have a new machine to
tie it to. The shortcomings of the then existing yardsticks
were painfully apparent to him. The electronics were poorly
done with low reliability and uncertain drift. Some of them
were limited by the lead screw which had about reached the
end of its advancement in capability and was slow. Othera
were limited by pulse detection and counting rate.
In looking around for a solvtion the best bet appeared to be
the phasolver. It offered the following advantages:
STAT
(a)
Determination of position was unique and us
ambiguous and did gat depend on counting pulses.
(b) It did not use a lead screw and the traversing
*peed was thus sat limited by the measuring speed.
(c) The electronics were well developed and had many
years of production and development debugging
behind them. The c4,1y phasolver electronics
were extraordinarily stable and free of drift.
Since linear measuring has acme problems different than
angular measuring I I decided to get them
started with a feasibtitty study. It is a good thing
he did, too.
NGA Review Complete
Approved For Release 2005/07/13 : CIA-RDP78604770A001500070007-3
Approved For Release 2005/07/13 : CIA-RDP78604770A001500070007-3
,1111111,
r Phasolver Measuring Engine
30, 1965
4-
olver works on the basis of determining the capawltive
between metallic patterns on two glass plates, e
d a coupler, which slide along each other. The
plate would be mounted on the stationary bed of tile
engine. The coupler pattern is merely straight
perpendicular to the direction of motion.
The driver would be mounted to the moving head of the meaburing
engine and its pattern has a sinusoidal variation as show
on the attached Sketch. TWo pattern designs were to be tested
in the feasibility demonstration.
The electronics measures the phase angle between ele trica
signals impressed on the driver and picked up by the coupler.
The phase angle varies with position, hence, the term
"phasolver." The entire problem 110: been the preparation o:i7 a
pattern by(
STAT d as much trouble with the linear patterns
STAT d making the original rotary patterns. The
project was stalled for about 10 months waiting for good
patterns. The electronics were completed almost a year al-Jo.
STAT Alter Ifinally made a good driver master pattern of
photographic emulsion on glass, made working pattern:
STAT from thai Imaster of deposited metal on glass. also
made the coupler.
The test program is now under way to determine how good the
phaeolver really is. Test results are encouraging but,
of oourse? not complete and iefinitive. The electronics aro
very stable and free of drift. When a measurement is set up
in the evening and left overnight, it is still registeriiv
the same measurement to 1/10 micron the next morning.
(Rome temperature is controlled to + 10F and relative
humidity varies less than + 3%.)
The pattern appears to have a scale error of about 15 microns
over its 20 inch length. A scale error was expected and .1
can be balanced out electrically. Also there appears to
be a variation from pole pair to pole pair of from 1/4
micron to about 1.1/3 micron. They are not sure whether Ails
occurs in the test equipment or in the phasolver, but they
suspect the test equipment. They are presently trying to
pin down the source of the error. Probably the most
Approved For Release 2005/07/13 : CIA-RDP78604770A001500070007-3
STAT
STAT
STAT