close

Вход

Забыли?

вход по аккаунту

?

Патент USA US3020556

код для вставки
Feb. 6, 1962
MJLOSHER
3,020,545
RADIO NAVIGATION SYSTEM
Filed Feb. 12, 1958
5 Sheets-Sheet 1
Inventor
MORTON £05709?
By
Attorney
Feb. 6, 1962
M. LOSHER
3,020,545
RADIO NAVIGATION SYSTEM
Filed Feb. 12, 1958
5 Sheets-Sheet 3
_
M
k
.+
\
.
m
m
u
a
f
AM
02|m|~
HO._
lunb /l‘
A
QM“s
5
BM
J
_
A4
M
P.
p.54
_
p/_.
H
-[iv0mlimL
_
F
.o
0mm
V
_
M5
w_
|—\
C
A
FM
_
_r
we
__
_
we
pm.
__
+
_r0
/10_
MR
n
i
_i:..
P
M
a:
4
pm
pa12_
n
L+
_
v/
_6//mx
_.s_
RWP
_
8
_L_
UA
MM
_
*
_
,3
m
_
|_Laa|.1| j
m
My
%
a
0
mp.
n{0i_i1|
LaWéo/wYl
_Q0’
5
m
p
P.
M
NA
_
+
Inventor
M0197’0N LOS/{fR
By
6‘
A Horn ey
.
Feb. 6, 1962
M. LOSHER
3,020,545
RADIO NAVIGATION SYSTEM
Filed Feb. 12, 1958
5 Sheets-Sheet 5
Byazeizfwww
Attorney
es
V
I
aszasis
fPatented ,Feb. 6, 19.62
i
,
the instantaneous position of ‘said receiver relative to a
3,020,545
. known point in response to signals ‘from said Loran re
RADIG NAVHGATEGN SYSTEM
‘Morton ‘Losher, Bergen?eld, 'N..l., assignor to ‘Interna
.tioual ‘Telephone and Telegraph =Corporation, Nutley,
N1, a corporation of Maryland
Filed Feb. 12, 1958, Ser. No. 714,751
6 Claims. (Cl. 343-493)
ceiver, thereby minimizing the error .in position intro
duced by thecraftls velocity.
,
Another object of this invention is to provide an analog
pes'itioncomputer for use with a Loran receiver on a craft
and responsive to signals therefrom and ‘manual input
signals, to compute said craftls position relative to .a
This invention relates to radio navigation systems and
known point preferablynear the craft.
particularly to systems utilizing the time dilierence in the 10 "It is a feature of ‘this invention to employ an analog
propagation of radio energy from synchronized beacons
computer responsive to hyper'boliccoord-inate signals from
to establish distances.
a ,Loran receiver-indicative of a craft’s position, hyper
In the past numerous radio navigation systems have
‘bolic coordinate signals indicative of aknown position
been employed which utilize the time dilference in propa
and signals indicative of the distance \frornsaid known
gation of radio wave energy, such as pulses emanating
position to the Loran transmitting vbeacons .to- compute
from beacons at a known position and detected by~equip~
said craft’s position relative to said knownposition.
ment on a craft to establish the position of the craft rela
Another feature of this invention is to provide analog
tive to the vbeacons. vOne such prior system commonly
integrating means to generate forcing ‘function signals
called Loran employs pairs of synchronized ground
indicative of the Cartesian coordinates of said .craft’s posi
beacons, each beacon of a pair transmitting radio wave
tion relative to said known, point which may .befed to
pulses vat-the same rate with precisely ?xed time relations
tbetweengiven pulses from each of the beacons of a pair.
Therpulse repetition rate of the beacons in ‘a pair serves
analog quadraticxequation solvers yielding signals indica
tive of the differences between the craft’s distance to each
Loran beacon and the distance from said known point to
each Loran beacon and to compare these signals indica‘
to identify the pair of beacons. in operation the pulses
.from two or more pairs of such beacons are radiated to
tive of differences with 'hyperboliccoordinate signals in
‘a craft or vehicle having radio receiving equipment where
dicative of the craft’s position and the position of said
an operator by means of this equipment and otherequip
known point yielding signals to control said analog inte
ment establishes two different pulse time differences, one
grating means and, thus, control said forcing ‘function
between the pulses from a ?rst pair of beacons and the
signals indicative of said Cartesian coordinates.
other between the pulsestrom a second pair of beacons. 30
Another feature is to provide two separate analog inte
:Each time difference represents a locus of points forming
grating means to p-roducesaid Cartesian coordinate signals
.a hyperbolic line one special map; thus, the point on they
and to provide three separate analog means to solve three
special map where the line representative of the time dif
different quadratic equations.
‘
ference between received pulses from a ?rst pair of
Another feature is to provide means to adjust scale so
beacons and the line representative of the time difference
that ‘the Cartesian coordinate signal output may signify
between pulses from a second pair ‘of beacons cross, indi
cates the position of the craft or vehicle.
more than one positional displacement of the craft relative
to said known position.
iOne difficulty with the prior radio navigation systems
Another feature is .toyprovide manual input controls to
and the Loran systememploying special maps is that an
generate signals indicative of the hyperbolic coordinates
operator must obtain information from the receiver, then 40 of said known point relative to said Loran beacons, the
subsequently transpose this information to a coordinate
distance from said known point toeach Loran beacon and
system on a special map to locate his own position. This
the bearing of said known point to each Loran beacon so
that during the course of navigation, said known point
process of obtaining information and transposing it is
time consuming, and if the operator’s craft is moving at
an appreciable speed, its position will have changed ap
preciably between the time the information is ‘received
may be frequently changed manually.
Other and further objects and features of this invention
will ‘be more apparent from the following speci?c descrip
tion taken in conjunction with the ?gures,_,in which: .
and obtained from the receiver and ‘the time it is ‘trans
posed to yield ,position from the special map. Thus the
FIG. '1 is a map view of a Loran hyperbolic coordinate
signal ?eld from which the geometry and equations com
operator is not able to establish the instantaneous position
of his craft on the map within the accuracy inherent to
the Loran receiver.
puted by the positioncomputermay be better understood;
Therefore, the primary object of this invention is to
provide an improved radio navigation system.
had;
FIG. 2 is a block diagram of the position computer item
which a general understanding of its operation may be
Another object is to provide a navigation system rem
ploying a position computer responsive to signals indica
tive of a craft’s position relative to a ?rst known position
and responsive also to signals indicative of a second known
positionrelative to said ‘?rst known position-to thereby
compute :the craft’s position relative to said-second-known
position.
Another objectof this invention is to ‘provide a naviga
tion system responsive -.to'signals'indicative-of a craftis
position relative to a knownposition to establishtthe craftls
‘FIGS. 3 and 3A are a detail ‘block diagram and elec
55
trical schematic of the position computer; and
FIG. 4 is a detail schematic of one of the three quad-p
ratic equation solvers shown in FIG. 3A.
Referring ?rst to FIG. 1, there are shown three Loran
beacons, a master M and slaves S1 and S2, transmitting
signals from which two .sets of hyperbolic coordinate
lines may ‘be established. One set of hyperbolic coordi
nate lines which are established by signals from beacons
M and S1 are shown as broken lines, while the other set
position relative to :another ‘.known position, which is
of hyperbolic coordinate :lines established bysignals from
preferably nearer to thecraft, thereby permitting the sys 65 beacons M and S2.are shown as solid lines.
tem to deal with ‘and compute shorter, distances resulting
It‘ a vehicle containing a Loran receiver is located at
in more accurately locating the position of said craft.
point P within range of tthe beacons M, S1, and Spat
,Anotherobject .of this invention is to provide a position
distances Dm', D1’ and D2’ vfrom the beacons, respective
computer for use with a LLoran receiver to establish the
ly, and it is desired to ?nd the coordinates Xp and YD
position ;of ‘the receiver. relative to. a known point.
70 of point P relative to a known point at O and the-dis
Another object of
invention is to provide a com
puter for use with a Loran receiver to rapidly establish
l i
Hi i
tances Dm, D1 and D2 of point 0 from beaconsM, S1,
and S2, respectively, are accurately known, as well asithe '
3,020,545
and by similar analysis the following can be shown:
angles ¢m, (p1, and p2, and the exact hyperbolic coordi
mates of point 0 are known, then there is sufficient in
formation available to compute Xp and Yp thereby lo
cating the craft’s position at P relative to the known
point 0 which may be at the center of a small area
map 1.
It should be noted that the positions of the Loran
beacons as shown in FIG. 1 are arbitrary and the tri
and solving the above equations for AD2, AD,,, and
ADl, the following quadratic equations are obtained:
angle they form is not necessarily a right triangle and,
furthermore, the known point 0 is well outside the tri' 10
angle formed by the beacon positions. The arbitrary lo
cation of the beacons and point 0, shown in FIG. 1, is
purposely employed to show the versatility of the em
bodiment of the navigation computer herein described.
It might be preferable from the standpoint of accuracy
that the beacon positions form a right triangle and that
‘small map 1 be smaller than shown and located within
(5)
the right triangle formed by the beacons.
In order to show that there is enough information
AD,,, z 21),,
1
available as outlined in the above paragraph to compute
Xp and Yp, consider the following strict derivation of
quadratic equations in terms‘of the precisely known fac
Referring next to FIG. 2, there is shown a general
block diagram of the position computer. The quadratic
tors outlined in the paragragh above and in terms of XI,
equation solvers 2 receive signals from the manual in~
put controls 3 which are indicative of the position of
point 0 shown in FIG. 1 relative to the position of the
beacons M, S1, and S2, also shown in FIG. 1. Quad
ratic equation solvers 2 are also fed signals indicative of
and Yp yielding the factors ADm, ADI, and ADZ which
are equivalent by de?nition to the following:
Xp, Yp, and Xpz-l-Yp2 from error integrating and squar
ing circuit 4 so that the factors ADm, AD1, and ADZ may
be computed by quadratic equation solvers 2. Signals
Let up and 51, be the time differences of radio pulses
detected from beacons S2 and M and S1 and M, respec
tively by the Loran receiver in the craft at P; therefore:
indicative of ADl and ADm are fed to comparing circuit
5, while signals indicative of ADZ and ADm are fed to
comparing circuit 6. Comparing circuit 5 is also fed
signals indicative of air-4x0, While comparing circuit 6
is also fed signals indicative of tip-{30. These compar~
ing circuits 5 and 6 compute Equations 1 and 2, respec
tively, yielding output signals indicative of
40
and ?;,—,60—AD2+ADm, respectively.
and consider triangle (APSZ). It follows by the Pytha
gorean theorem that:
antennas 12.
(AP)2=(XI,~D2 cos 11:2)? since cos ¢2 is negative
and:
(S2B)=D2 Sin ¢2
The factors
nip-a0 are computed by comparing means 7 in response
to do from manual input controls 3 and up from Loran
receiver 8, while the factor [Sp-Bo is obtained from com
paring means 9 in response to ,60 from manual input
controls 3 and pp from Loran receiver 8. The Loran
receiver 8 receives signals via antenna 10 which are
transmitted from the Loran beacon transmitters 11 via
The action of error circuit 4 in response
50 to error signals from circuits 5 and 6 is to vary the out- -
put signals indicative of Xp, Yp, and Xp2+Yp2 fed to
quadratic equation solvers 2 until said solvers yield sig
nals indicative of ADm, ADl, and AD2 which when com
pared in circuits 5 and 6 with the 0c and it signals yield
zero error signals. In other words, error circuit 4 varies
therefore:
(Dz')2= (D2-i-AD2)2
therefore:
the values of XI) and YB until the error signals from cir~
cuits 5 and 6 are nulled. The Xp and Y1, indicators, 13
and 14 respectively, coupled to circuit 4, are provided to
indicate the coordinates of the craft’s position relative
60 to known point 0.
Referring next to FIGS. 3 and 3A, there is shown a
detail diagram of the position computer. In operation
signals from beacons M, S1, and S2 are detected by
antenna 10 and fed to Loran receiver 8 wherein up and
tip signals are computed as shaft rotations and coupled
to synchros 15 and 15a, respectively, which in turn
energize synchros 16 and 17, respectively, whose output
and in this equation:
shaft positions are applied to differential gear boxes 18
and 19, respectively. Shaft rotations 20 and 21 from
70 manual controls 3, indicative of a0 and 50, respectively,
are applied to gear boxes 18 and 19, respectively, which
in turn drive potentiometers 22 and 23, respectively.
Thus, the voltage output from potentiometer 22 is equiva
lent to tap-a0, while the voltage output from potenti
ometer 23 is equivalent to ?p—,80.
3,020,545
6
Meanwhileshaft rotations 24 through 29 are fed from
tentiometer 65 is proportional to XI,2 and the voltage in
arm 67 of potentiometer 69 is proportional to Ypg.
Arms 63 and 67 ,feed voltage signals to summing ampli
input controls 3 to potentiometers 30 through 35. These
potentiometers, 36 through 35, are energized by signals
from double pole switches 36 through 41, each of which
?er 52 wherein XD2 and Y;,2 are added and their sum
is positioned from manual controls 3. The poles of
then fed to each of quadratic equation solvers 46, 47,
switches 37, 39, and 41 are energized by signals indica
and 48. The outputs of ampli?ersltd and 45 are each
tive of +Yp or —Y,, from ampli?ers 44 and 45, respec
fed to one pole or the other of the polesof double pole
tively, in the manner shown, while the poles of switches
switches 37, 3?, and 41, while the outputs of ampli?ers
36, 38, and 4% are energized by signals indicative of
42 and 43 are each fed to one or the other of the poles
-|-Xp or ~Xp from ampli?ers 42 and 43, respectively. 10 of double pole switches 36, 38, and 4%. The output of
Thus the ouput voltages from potentiometers 34) through
ampli?ers 42, and 44 also provide signals to Xp indicator
35 provide the factors Xp cos¢ and Yp sin ¢, of the
'13 and Yp indicator 14, respectively.
proper sign to their appropriate quadratic equation solv
The ?eld coils of servomotors '66 and 61 are ener
ers 46, 47, and 43, which solve Equations 3, 4, and 5,
gized by signals from double pole double throw switch
respectively. Mechanical couplings 49, 5tl,land 51 feed ~
76' so that depending upon the position of switch 76, a
shaft rotations proportional to
given signal to each servomotor from its associated servo
ampli?er will cause the motor to rotate in one direction
or the other. Double pole double throw switch 70 isv
1
7 and '27);
positioned by mechanical linkage 71, which is operated
to quadratic .solvers 46, 47, and 48, respectively. Each
quadratic equation solver is also fed a signal propor
tional to Xpz-l-Yp2 from summing ampli?er 52 via lines
52a. Thus all the values required to solve, Equations 3,
.4, and 5 for ADI, AD2, and ADm are fed to quadratic 25
equation solvers 46, 47, and 48, respectively.
The outputs from the quadratic equation solvers 4-5
and 47, which are indicative of AD1 and A132, respectively,
from manual input controls 3 depending upon the op
eration of the position computer as evidenced by XD
and Yp indicators 13 and 14, respectively. if these indi
cators present values of XI, and Yp which appear un
stable or change considerably more than is expected from
the motion of the Loran receiver when switch 70 is in
one position, then switch 78 should be positioned in its
‘other position. Potentiometers 30 and 31, 32 and?f’l,
and 34 and 35 are mechanically driven from manual
are fed to double pole double throw switch 53 which is
input controls 3 to yield the sine or cosine function of
positioned by mechanical coupling 54 from manual input 30 angles p1, ¢2, and ¢m, respectively, by mechanical cou
controls 3. Thus the outputs from quadratic equation
plings 24 to 29, respectively, as shown in FIG. 3A.
solvers 46 and 47 are each fed to different ones of sum
Since the angles ¢1, ¢2, and qbm are known (see FIG. 1)
ming networks 55 and 56 of servo ampli?ers 57 and 58,
when the Loran receiver 8 is located in any particular
respectively, depending upon the position of switch 53.
map 1 having its center at known point 0, the sine and
Manual coupling 54 also positions double pole double
cosine functionsof angles ¢1, 4&2, and rpm are’also known
throw switch 59 applying the outputs from the (mp-a0)
and may be inserted by the appropriate mechanical cou
potentiometer 22 and the (?p—,8o) potentiometer 23 to
plings 24 to 29.
di?erent ones of summing networks 55 and 56 so that
Referring next to FIG. 4, there is shown a detail elec
ap—a,, and AD1 are applied toone of the summing net
trical schematic of one of quadratic equation solvers 46,
works 55 or 56 and (fip—?o) and ADZ are applied to
47, or ‘4%. For purposes of explanation assume this is
the other, depending upon which set to the hyperbolic
lines running through map 1, shown in FIG. .1, is more
quadratic equation solver ‘46 which solves Equation 3
yielding a signal indicative of ADI. The inputs to quad
ratic solver 46 are mechanical coupling 45, voltage sig
parallel to the north direction N. If the a hyperbolic
lines (broken lines) are more parallel to the north di
nals from potentiometers Stl'and 31 via lines 30a and 31a
rection than the 5 hyperbolic lines, switches 53 and 59 45 and a voltage signal from summing ampli?er 52, via line
should be positioned so as to apply ap—<xu and‘ AD1 to
52a. Lines Calla and 31a are coupled to different termi
summing network 55 and [Sr-5,, and AD2 to summing
nals of input network 78, thereby feeding voltage signals
network 56.
proportional to Xp cos ¢1 and Yp sin 4&1 from potentiom
'
Summing networks 55 and 56 are each also fed‘a sig
eters 3t? and 51, respectively, to input network 73. Other '
nal voltage proportional to AD,,, from quadratic equation
solver '48. The outputs summing networks 55 and 56
inputs to network 78 are a signal from line 79 indica
tive of
are coupled to servo ampli?ers 57 and 58, respectively,
in such a manner that the output voltages from servo
Xp2+Yp2—AD12
2D1
ampli?ers 57 and 58 energize servomotors 6th and 61,
respectively, causing these motors to turn at a speed pro
portional to the voltage output from its associated servo
ampli?er. The outputs of motors 6t} and 61 are coupled
to arms 62 and 63 of potentiometers 64 and 65, erespec~
tively, while the output of servornotor 61 is coupled to
arms 66 and 67 of potentiometers 68 and 69, respec
tively. Opposite ends of potentiometers 64 and 68 are
applied opposite polarity A.C. signals, while the center
tap of each of potentiometers 64, 65, 68, and 69 is
grounded. Thus the signal applied from potentiometer
55 and a signal via line 36 proportional to M31 as shown.
Summing network 78 serves to sum the aforementioned
voltage signals applying a sum voltage signal to servo
ampli?er 81, which in ,turn is coupled to and energizes
servomotor :8'2.
Motor 82 drives potentiometer arms
83 and S4 of potentiometers 85 and 86, each of which has
its center tap connected to ground. Potentiometer. 35
. has its ends coupled to opposite A.C. polarities, and the
voltage in arm ‘83, which is coupled to input network
87 and thence to ampli?er o8 and which is indicative
arm 66 to ampli?er 45 is proportional to +Yp, while
of ADI, is reversed .in polarity at the output of ampli?er
the signal applied from potentiometer arm 62 to ampli
88; thus, the output of ampli?er 83 is indicative of —AD1.
?er 43 is proportional to -|-Xp and the output from am
This —-AD1 output is fed to input network 35 of'ampli?er
pli?er 43 is indicative of -—Xp, while the output of ampli
5d and also to one end'of potentiometer 86, while the
?er 45 is indicative of —Y,,. The actions of ampli?ers
output of ampli?er 96, which is indicative of +AD1, is fed
42 and 44, which are coupled to the outputs of ampli 70 to the other end of potentiometer 86. The +AD1 output
?ers 43 and 45, respectively, are merely to change the
of amplifier 96 is fed back to input network 78 via line
sign of X1,, or Yp providing signals indicative of +Xp
and —Xp to opposite terminals of potentiometer 65
and signals of +Yp and —Y,, to opposite terminals of
potentiometer 69.
Thus the voltage in arm 63 of po
Stl; thus, the action of shaft rotation from motor 82 cou
pled to arm 84 which is proportional to A131 serves to
multiply the shaft rotation times the voltage applied to
the terminals of potentiometer 86, yielding a signal in
3,0 cases
14
if!
a‘)
line H which is proportional to ADIZ. Lines 91 andSZa ,
are coupled to input network §2 of ampli?er 93 whose
output is proportional to the sum of voltages in lines 91 I
and 52a and thus the sum of (Xlgz-l-YplbADlz). > The
generating means to correct the'values of the Cartesian
‘ ' coordinates produced thereby.
3. ,A system according to claim 2, further including in
dicating means coupled to said'assumed signals’ generating
output of ampli?er 93 is fed to one terminal of potentiom $1 means for indicating said Cartesian coordinates.
4. A radio navigation receiver adapted to be carried
~ star-‘94 whose arm 95 is positioned by shaft 4&9 whose
on a craft and cooperating with a plurality of Loran
‘rotation is indicative of
beacons for indicating inCartesian coordinates the dis
__._L___
placement of said craft with. respect to. a known point
2131
'10 which may be selected to be one of, said plurality of
Thus, the voltage, in arm 95, which is coupled to line 79,
is indicative of
~
XPZ-FYDLFADIZ
2o1
The output voltage of quadratic ‘equation solver 46
which is proportional to A131 is obtained from arm 33
of potentiometer 85 and is fed to one arm'oi double pole
double throw switch 53 shown in PEG. 3.
I
While I have described above the principles of this in
vention in connection with speci?c apparatus, it is to be
clearly understood that this description is made only by
way of example and not as a limitation to the scope‘ of ‘
. my invention as set forth in the objects thereof and in
the accompanying claims.
‘1. A radio navigation receiver adapted to be carried
on a craft and cooperatingwith a plurality of Loran
Loran ‘beacons comprising means for receiving signals
from said beacons, means for deriving from the received
' signals a pair of time difference signals with one of said
time di?erence signals representing the difference in time
between signals received from a ?rst pair of said beacons
and the other time difference signal representing the dif
ference intimebetween signals received from a second
pair of said beacons, means to generate a second pair of >
time di?erence signals representing similar time difference
signals at the known point, means for generating assumed
signals indicative of the Cartesian coordinates representing
"the displacement of theicraft from the known point, means
‘for generating polar coordinates representing the position
of said point with respect to said beacons,>means for
computing from said assumed signals and said polar co
»ordinate signals ‘the differences inthedistancesof the
known point and the craft to each of said beacons and
producing computed distance difference signals rcpre~
> sentativethereof, means .for computing from these com- ,
eacons for indicating in Cartesian coordinates the dis—
placement of said craft with respect to a known point 30 puted distance di?erence signals ‘and the time di?erence
signals of said craft and said‘point error signals repre
which may be selected to be one of said plurality of Loran
beacons comprising means for receiving signals from said
beacons, means for deriving from the received signals
measured distance diiference signals indicative of the
craft’s position relative said known point, means for gen
senting the error in the values of said ‘assumed signals,
and means for applying said errorsignals tosaid assumed
signals’ generating means to correct the values of said
, assumed signals so that said assumed signals more pre
cisely correspond to the said Cartesian coordinates of said
craft withrespect to said known point signals.
,5. A system according to claim 4,'whereinsaid means
signals indicative of the Cartesian coordinates ‘of ‘said > *
for receiving comprisesmeansfor receiving signals from
craft’s displacement relative'to said known point, means
for computing from said assumed signals, other signals 40 a ?rst, second, and third beacon and wherein said ?rst
erating hyperbolic coordinate signals indicative of the.
position of said known point, means to generate assumed
indicative of ‘the differences between the craft’s‘ distance ‘ >
to each said beacon and the distance from said known
point to each said beacon, means to compare these com
. and second beacons formone of said pairs, and said Sec
ond the third pairs form the other of said pairs,
6. A radio navigation receiver adapted to be carried on
a craft and cooperating with a plurality of Loran beacons
puted difference distance signals with the measured dis
tance diiference signals indicative of the craft’s position
relative said known point and the position of said known
point to yield error signals, and ‘means for applying the
for indicating in Cartesian coordinates the displacement
error signals to said assumed signals’ generating means
means‘for deriving from the received signals a pair of
time difference signals with one of said time di?’erence
to correct said assumed signals so as to drive said gen
erating means to values more precisely indicative of the
Cartesian coordinates representing the displacement of
the craft’s position from the known point.
2. A radio navigation receiver adapted to be carried on
a craft and cooperating with a plurality of Loran beacons
for indicating in Cartesian coordinates the displacement
of said craft with respect to a known point which may be
selected to be one of said plurality of Loran beacons com
of said craft with respect to a known point which may be
selected to be one of said plurality of Loran beacons
comprising means for receiving signals from said beacons,
signals representing the difference in time between signals
received from a ?rst pair of said beacons and the other
time difference signal representing the difference in time
between signals received from a second pair of said
beacons, means to generate a second pair of time differ
ence signals representing similar time diilerence signals at
the known point, means for comparing the received time
di?'erence signal and the generated time dilierence signal
prising means for receiving signals from said beacons,
of one pair of beacons to produce a ?rst signal, means to
means for deriving from the received signals measured
the received time difference“ signal and the gen
distance difference signals indicative of the craft’s posi 60 compare
erated time diiference signal of the other pair of beacons
tion relative said known point, means for generating
to produce a second signal, means toproduce assumed
hyperbolic coordinate signals indicative of the position of
signals
indicative of the Cartesian coordinates represent
said known point, means to generate assumed signals in
ing the displacement of the craft from the known point,
dicative of the Cartesian coordinates of said craft’s dis
means for generating further signals representing the polar
placement relative to said known point, means for gen
coordinates from the known point to the different beacons
erating signals representing the polar coordinates of said
forming said pairs, meansfor computing from the as
point with respect to said beacons, means for computing
sumed signals and said further known signals the differ
from said assumed signals and said generated polar coordi
ences in the distances of the known point and the craft to
nate signals the differences in the distances of the known
point and the craft to each of said beacons, means for 70 each of the beacons forming said pairs and producing sig
nals representing each of said distance differences, means
computing from these distance differences and said meas
for taking the difference ‘between different pairs of said
ured distance di?erence signals of said craft and said point
distance difference signals to provide a third and fourth
the errors in the values of the assumed signals and for
signal derived respectively from said ?rst and second pairs
producing error signals representative thereof and means
for applying said error signals to said assumed signals’ r of beacons, means for comparing said third and fourth sig
'
'
8,020,645
9
10
nals with said ?rst and second signals, respectively, to
p_rod1l1ceten'or sigxtlaltil and 11163138 fer allaplyintglthese e?rqr
slgna s
o correc
e assume
slgna s un 1
a nu
1s
preclsely
reached, the Cartes1an
corrected coordinates
assumed signals
expressmg
representing
the dlsplecemore 5
ment of the craft from the known point.
References Cited in the ?le of this patent
UNITED STATES PATENTS
'
2:717:735 .
Luck
5,1522?
________________
"7 ------------__
~- Sept.
111;? 13’
g’ 1955
Документ
Категория
Без категории
Просмотров
0
Размер файла
1 040 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа