US2370966A - Method and apparatus for navigating aircraft - Google Patents

Description

@RUSS REFERENCE SEAHUH Huuw March 6, 1945. `w- T. JocHUM METHOD AND APPARATUS FOR NAVIGATING AIRCRAFT original F11ed oct. '27, 1954 15 sheets-sheet 1 March 6, 1945. w. T, JQCHUM 2,370,966

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METHOD AND APPARATUS FOR NAVIGATING AIRCRAFT Original Filed Oct. 27, 1954 l5 Sheets-Sheet 7 METHOD AND APPARATUS FOR NAVIGATING AIRCRAFT Original Filed Oct. 27, 1954 15 Sheets-Sheet 8 March 6,I 1945. w, T. JocHUM METHOD AND APPARATUS FOR NAVIGATING AIRCRAFT l5 Sheets-Sheet 9 .ggmvxx Original Filed Oct. 27, 1934 Mw k.

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METHOD AND APPARATUS FOR NAVIGATING AIRCRAFT Original Filed Oct. .27, 1954 15 Sheets-Sheet 14 Fig. 56.

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NN WM Patented Mara, 1945 f UNIT-E- i'gimiuio4 BIETHOD AND APPARATUS FOR NAVIGATING AIRCRAFT '1'. Jochum, Manhattan oeuf.

- application october 21, 1934, sei-an No..

.l 7,311. Divineo ano im annulation omheic, 1939, serial No. somosi ici; sii-1c.)

includes an aerial mapping camera of the reflex mechanism.

mining the relative movement between an earth object, or an image ofthe earth, and an aircraft for the purpose of determining the azimuth and -velocity of motion of said aircraft with respect to said earth object. Y

A primary advantage of the navigational1 method herein described is accomplished through the cooperation of a` manually operated and properly controlled driftsight with a conventype, the reflex mechanism thereof incorporating e driftsight as an integral part `of the camera in conjunction with the means for viewing an earthrobiect, or an image of the terrain below the aircraft, achieved in conjunction with said reflex The reex, or reflecting, elements ofthecam ero, drlftsight may be of suchdimen'sions that theimag which appears on the ground glass, or. viewing screen, thereof includes identically the same area of terrain as that recorded lon the film when a photographic exposure is caused to occur, and said image may be identically the same size as that recorded on the film.

The simplied method of navigationrealized in commotion with the application of my inventional compass to cause said aircraft to, at all v times, indicate to thepllot of the aircraft whether or not said aircraft is actuallyfollowing a predetermined compass course along the earth as delined by a line along the earth corresponding to said predetermined compass course'.

Said proper control of said driftslght .further includes the orientation thereof in such a manner that a drift line, or radical line, or radical axis of the driftsight is, substantially at all times. maintained parallel to the direction o f motion of an image of the earth, or an earth object as ob-- served in commotion with any suitable means for viewing the earth.

Said proper control of said driftsight also includes the relatively constant maintenance of the principal axis of the lens, or other equivalent Y moana normal, or at right angles to, aline tangent to the surface of the earth assuming for illustrative purposes that the earth is a' perfect sphere, at all times in conjunction with reference bythe operator oi saiddriftsight to a conventional suitable levelling means, or equivalent levelling instrument, such as a level bubble, herein used for illustrative purpose. In other words, the principal axis of the lexis of the dflitsight or other equivalent sighting means must be maintained in a constant position with respect tothe V earth, preferably in a vertical position.

It is stressed that the proper control of the driftsight requires the relatively constant maintion is particularly valuable when employed for aerial mapping purposes, in which oase it is necessary, conventionally, to fly an aircraft along a number of parallel courses for the purpose of taking a. sequence of pictures to completely cover the area. In thephotographing of each of the strips ofpicture required to cover the area it is necessary for the aircraft to be flown on a predetermined course with a minimum of deviation therefrom.

The pictures are conventionally taken at such intervals' of time that successive pictures overlap each other by 'a predetermined amount.

The spacingbetween adjacent strips is made such that the successive strips of pictures also overlap 'each other by an amount sumclent to provide for deviation from a straight predetertenance thereof in a constant relationship with respect to the earth, since any rolling motion, or oscillatory motion, of the aircraft about the approximate longitudinal axis of the fuselage is conL duoive to apparent lateral-motion'oi the earth object, or image of the earth, with respect to said drift line, or radical axis, of said driitsight.

As herein disclosed, the driftsight preferably mined compass course that must 'be parallel to' the course of theadjacent strip, or strips. The amount` of lateral'overlap employed in determining the spacing between strip courses is, therefore, a direct function of the precision and facility with. which the aircraft is navigated.

With my method, once the compass has been adjusted for a predetermined compass course, the operator of the camera driftsight is enabled to accomplish the navigational function without expending any more effort than is conventionally required in the normal operation of a conventional mapping camera. No extra mental effort is involved, as the navigational function is automatically accomplished in conjunction with the conventional operation of the camera driftsight, or aerial mapping camera including a drlftsight.

It involves no more eort for the pilot of the aircraft to control the aircraft in response to the indication of a compass indicating instrumentl than is involved in following the indication of'a conventional compass, the pilots duties being actually simplied, since driftcorrection is auto matically accomplished by my method -for causa whether or not the aircraft is following a predetermined compass course as defined by' a -line 'along the 'surfaceof the earth coinciding with said compass course. It is unn to apply a drift correction to the compass indication. as is required in conjunction withv the use of a conventional compass.

Without further explanation. it is assumed that it is understood that, although an aircraft may be down in a conventional manner without drift correction and by reference to the indication of a compass, the aircraft may. under this condition, actually re following quite a different course with respect to the earth than that indicated by the compass. due to the fact that the direction of the wind in' which the aircraft is4 flying may not be parallel tothe desired compass l course, with the result that the aircraft, unless properly crabbed, or turned to compensate for a wind direction not parallel to said desired compass course, may follow a course with respect to the earth that corresponds to the resultant of two vectors corresponding. respectively. to the airspeed of the aircraft and .the velocity of the wind in which the aircraft is'dying.

When theaircraftis flown in a wind. the di- 4 craft, to be extremely erratic, due to lateral drift of the aircraft, and the strip courses flown under conditions involving the'fiying of the aircraft in a wind not parallel to the course it has been desired to ny have been so irregular, due to lateral drift of the aircraft,`that the resultant strips of photographic pictures obtained have often failed entirely to overlap each other laterally, and a portion of the area which it has been desired to photograph has been missed entirely. Ithas A further object of this invention is to provide for installation in a mapping aircraft a condensed and comprehensive indicator panel forl the useof the pilot of said aircraft. thereby facilitating the control and operation of said aircraft for aerial photographic purposes. I

A further object of this invention 'is to provide for use in conjunction with an aerial photographic mapping camera and driftsight, in 'combination therewith. a new and improved type of mapping cameras, or other types of instruments capable of being employed as a means for determlning the angle of drift of an aircraft in night, said mounting includingmeans whereby said camera or instrument may be maintained with a predetermined axis thereof in a predeter-' mined relationship to the vertical axis as defined by a suitable levelling reference means. such as a level bubble.

A further objectof this invention is to provide an improved type of rotary mounting for aerial mapping cameras, or other instruments capable of being adapted to determine the angle of Udrift of an aircraft in flight, said mountingl including means to facilitate the maintenance of said cameras or instruments with a predetermined axis thereof 'at all times having a predetermined relationship with respect to'the vertical as often been necessary to, at great expense and loss of time, make additional flights for the purpose of obtaining photographs of the area which f has been missed in this manner. Because of the defined -by a conventional levelling reference means such as a level bubble, and said mounting further including means to control a conventional compass in such a manner that said compass may be caused to indicate whether or not another predetermined axis of said camera or instrument is in coincidence with a predetermined compass course.

A further object of this invention is to provide, in conjunction with the mounting previously described. a compass controllng means previously described and further compass controlling means to permit the adjustment of said compass to cause it to indicate the relationship between a predetermined axis of said camera or' instrument and any predetermined compass course.

A further object of this invention is to provide,

in conjunction with the mounting and compass mal lateral drift of the aircraft which has occurred when existing methods have been employed in aerial photographic mapping.

My method of navigation permits the reduction to a minimum of said lateral overlapping of the resultant strips of photographic pictures, with a resultant economic saving, as well as a saving in time.

, It is contemplated that' the aerial photographic camera driftsight herein described, when used in conjunction with the method of navigation herein described. will permit the use'o'f aircraft p ilots who have not had special training in the art of aerial navigation for photographic mapping purposes.

A further object of thisinvention is to provide a new and improved method of navigating aircraft.

controlling means and camera and/or drlftsight or other instrument, respectively previously described, a means to indicate the predetermined compass course for which said compass has been preadjusted.

A further object of this invention is to provide a releasable means for holding the -said :haunting in any position of rotational orientaion. v

A further object of this invention is to provide in conjunction with said camera, or other instrument, an altimeter adapted to cooperate with and control a remotely located means to indicate the reading thereof.

A further object of this invention is to provide,

' in conjunction with said camera. means to facilitate the determination ofthe velocity of motion of the aircraft with respect to the earth.

The invention consists in. the novel parts and combination of p to be described hereinafter, all ofwhich, in coniunction with the method def scribed hereinafter. contribute to the accomplishment of the function of navigating an aircraft in 'an improved mer.

l is p viewer the camera and'moimt.

nonlinsd-Bof ills. i and closes the era and mount.

3 is a ses plan view, partly in section, i -i on line 3--3 of Fig. 2 I the earth inductor com b drive shaft.

d is a lower part i 2 and disci the cards, or indicar di.

Fig. i5 is a sectional view taken'in plan on line l-Iof Fig. 2 and discloses the-compass dial or' `card driving gear and means for the earth inductor brush drive pinion from the' rack or segment on the camera mount carriage.

Fig. 6 is a side elevation taken on line l of Fig. 1 and discloses the camera and mount.

Fig. 7 is an end elevation taken on line 'I-l ofv Fig.; and discloses the camera and mount from the opposite direction to that shown in Fig. 2.

Fig. 8 is a. sectional view in elevation taken on the une ci rig. 4 and discloses :negeer drive to the compass cards.

Fig. 9 is a side elevation taken on line H oi Fig. 1 Aand discloses the camera and mount taken from the opposite direction to the elevation shown in Fig. il.

the line iii-Il of Fig. 2 and discloses the earth inductcr'compass drive shaft and the gear drive tothe compass cards. f

Fig. 11 is a sectional view in elevation taken on line Ii--H of Fig. 2 and discloses the earth iiin chieste or this invention will Pwwtahen animal-4 v sa' Fig. is a sectional view in elevationtalgen on ducto!" brush drive shaft and means fordisensing the earth inductor brush drive Ashaft pinion from the rack on the camera mount carriage.

Fig. 12 is a sectional view in elevation taken on line I2i2 of Fig.' i and' discloses the'installation of the earth inductor compass indicator inv strument in the camera and also discloses one-oi f the warning lights. Y

Fig. 13 is a sectional view in elevation taken ori line II--Il of Fig. 1 and discloses the disposition y of the reflex elements of the camera driftsight.

Fig. 14 is a sectionalk view in elevation taken on line lI-M-of Fig. 16 and discloses the warn ing switch actuated by the intervalometer.-

Fig. is a sectional view in plan taken on line iB-Ii of Fig. 12 and discloses the construction of the reflex elements of the camera driftsight. Fig. 16 isa sectional view in elevation taken on the line 'll-II of Fig. 13 and shows the ground glass, or viewing screen, of the camera in elevation. together with means for facilitating the deasvacce l 3' glass,orvicwingscreenofthereiiex camerawith linea thereon facilitate navigation of the .air-

Flaco is a wiring diagram for theesrin inductorcompassindicato'rsysiem.`

-Fig.21isaplanviewofthecameramountata reducedscaleandissimilartollg. 1 with'thecamera driftsight removed. Fig. 21 also shows a.

wind excluding apron omitted in -other views.

Fis. 22 'is a side elevation of the camera mount shown lnFig.`2l and is similar to Fig. 6 with the ra driftsight remgyed.

Fig. 23 is an end elevation of the camera mount sh0WninFi$.2 1andissimilartoFlg.2with the era driftsight removed.

Flam is a fragmental sectional view` tekenen line 2'4-2 of Fig. 21 and-discloses the camerav mount yoke Journal and bearing 'by means of which said yoke, or trunnion, may be tilted in the mount.

. ne. as is s fragmentsl sectional view taken on line Il -II of Fig. 21 and discloses the spring actuated pins on which the .camera driftsight pivots in the yoke.

rig; 2s is a fragmentai view taken on une' -zl of Fig. 21 and discloses a portion of the carriage and track with partsbroken awayto disclose the spring brake in a holding position.

:visavisaviewsimiiari.c1\'is.26andaisciosesv the spring .brake released to permit rotation of the mount. A

F18. 2 8 is a sectional view taken on line 2l-2I of 21 and discloses the bearing and centering rollers on which the camera mount carriage rides and by means -of which said mount is centered over the track.

Fig. 29 is an elevation of the remote indicator panel.

Fig. 30 is a side elevation of the remote indi cator panel.

Fig. 31 is yasectional view taken online "-31 portion of the track.

- Fig. 35 is a sectional view taken on line 35-32 oi Fig. 38 and discloses the shape of the supporting members for the vconventional gimbal wh is mounted a conventional camera to which 'a driftsight has been added. v

' Fig. 36 is a plan view at a reduced scaledistermination of the velocity or motion of the aucraft with respect to theearth.

Fig. 17 is a sectional view in elevation taken on line ll-i'l of Fig. 16 and discloses means for tripping the camera tocause a sequence of exposurestooccurinaccordancewiththevelocity ofv motion .oi the image on the ground glass oi the camera. Y

closing the modiiled camera mount in further detail. i

Fig. 37 is a sectional view taken on line 317-313 oi' Fig. 33 and Fig. 43 and discloses the edimable indicator by means of which is determined the proper distance the earth image must travel between successive photographic exposuresA to Fig. 13 is a sectional view in elevation taken 'on line ll-ll of Fig. 1d and discloses the beit employed to synchronize the mechanism shown in i'i with the motion of the image on the'm 3mm@ oi the am,

obtainv a predetermined percentage ofV picture overlap.

Fig. 33 is an end elevation taken on line 3-3 3 of Fig. 36 ard further discloses the m camera mount.

. rig. as iss/side elevation taken on une ss-sa Fig. 36 and further discloses the modiiled compra mount.

g. 40 is a side elevation taken on line Il-Il of Fig. 36and further discloses the modified camera mount. Fig. 41 is a fragmental view taken on lin li-Ilvof Fig. 42 and discloses a plan viewl of the driftsight.

Fig. 42 is a fragmental plan view taken on line 42-42 of Fig. 39 and further discloses the driftsight.

Fig. 43 is a fragmental elevation taken on line 63-43 of Fig. 38 and further. discloses the drift- Fig. 44 is a'fragmental elevation taken on line u-u of Fig. 40 and further disclom the driftsight.

Fig. 45 is a fragmental sectional view taken on line ll-- of Fig. 42 and further discloses thedriftsight. v

'I'he navigational method and means disclosed in this specincation includes the following units: Referring to Fig. 6 the camera driftsight is i. Referring to Fig. 6 the mount is l. Referring to Fig. 4 the earth inductor compass controlling mechanism is 3.

The modified conventional altimeter unit is l. The remote indicatorpanel is l. i The modified camera mount is l. The conventional aerial camera is 1. The driftsight for the conventional aerial camera is I.

The driving elements for the reflex mappingA camera are l.

The drawings illustrate an embodiment of my 35 whereby the image of the earth is, practically at all times, formed, in conjunction with a camera lens and a reflector on a ground glass or viewing screen, said image being in focus thereon. The

operator of the camera drlftsight views the image on the ground glass by means of a reector included in a viewing-hood. The reflection of the earth image on the ground glass is interrupted only for a brief period during the photographic exposure of a negative. Further means are also provided whereby the frequency with which the photographic exposures occur automatically may be regulated in accordance with the velocity of motion of the image on the ground glass.

The aerial photographic camera driftsight herein described is mounted pivotally in a rotary mount in such a manner that the camera driftsight may be manually levelled in coniunction with a suitable conventional means, such as a level bubble, at which time the ground glass in my reex type of camera driftsight is in a vertical plane, or substantially so, and the principal axis of the camera lens is substantially in la vertical position. In the case of a conventional camera modiiied to include a driftsight the principal axis of said driftslght, or equivalent means.

is similarly maintained in a substantially vertical position. and the ground glass, or viewing screen, 15

Other types of conventional of said driftsight is substantially in a horizontal piane at this time.

l This levelling ofthe camera drlftsisht facilo itates ythe accomplishment of a very accurate l drift'reading, or determination, in conjunction with the observation by the operator of the direction of motion of the image appearing on the ground glass. Reference means, in the form of a line on said ground glass, or other equivalent l0 means, is provided to facilitate the orientation of thecamera driftsight in such a manner that the motion of the earth image on the ground glass ls tion of motion' of the aircraft with respect to the earth. Any lateral rolling motion, or longiaudinal pitching motion of the aircraft would otherwise cause the earth image on the ground glass to appear to move in a manner not truly 20 representing the direction of motion of the aircraft with respect to the earth, and an erratic drift reading lwould be obtained in the latter case. It is imperative that a driftsight be provided with means to eliminate the error arising 25 from motion of -the aircraft other than motion corresponding with the forward progress of the aircraft. The method of navigation herein disclosed includes the flexible mounting of the driftsight to permit the levelling thereof by mov- $0 ing said driftsight independently with respect to the aircraft to permit correction of said error. The motion of the earth image on the ground glass of the driftsight is truly in accordance with the motion of the aircraft with respect to the earth when the driftsight is levelled as described.

The driftsights herein described are, respectively, provided with mountings which permit I them to be tilted with respect to the aircraft for levelling purposes and which incorporate car- 40 riages which lturn with said driftsights as manuing, the brushes in a conventional earth inductor compass, said brushes being thereby caused to maintain a constant orientation with respect to the radical axis of each driftsight. Said constant orientation of said brushes may be termed the angular relationship." The application of other types of remotely controllable compasses to the navigational method herein disclosed will be obvious to anyone skilled in the art.

'I'he pilot of the aircraft is provided with an indicator panel incorporating a conventional earth inductor compass directional indicator instrument. When the camera driftsight is oriented in such a manner that the motion of the earth image is parallel to the radical axis of the driftsight said earth inductor compass directional indicator instrument will indicate to the pilot of the aircraft whether or not the aircraft is travelling in a direction vwith respect to the earth corresponding to a predetermined compass course for which the compass has been initially adjusted and which it is desired to'ii'y. Said conventional earth inductor compass directional indicator instrument is conventionally adapted to also indicate in which direction the aircraft must ling means and conventional connecting shaft- 2.8705606 l l, l be turned to cause it to trav'elalong laid pre- Aan acceleration component which is incidental determined compass course in the event' the head-f ing ofthe aircraft is not correct.

A meansisjprovides whereby the 'said mn inductor compass brushes may be adjusted for sired to fly, further means being provided to' in'- dicate the heading for which. brushesare initially adjusted.

-With the navigational method herein disclosed the aircraft maybe readily flown on a prede termined compass course along the earth regardless of wind conditions, as theaircraft Vis automatically placed at the proper angle of 'crab to compensate for cross-winds when the motion oi l the navigational method herein disclosed, othertypes of aerial photographic cameras may be proor equivalent means, and used in conjunction with the camera vmountings herein disclosed.

The camera driftsight preferably includes means whereby the mechanismtherein may be ter. Means are included'in the camera driftsight to manually vary the frequency with which to auch maneuvering and which causes an erratic indication of the level bubble,with the result that-an exposure made at 'such a time will resuitin a tilted. o r distorted, photograph. The any desired compass course which it may be desaid' compass l same warning'means is also caused to function manually tripped to cause thel when the camerale exposure of a negative. e camera varmsteun 'me camere. dntsight l induces a housing mL' is projected onto .the iilm therein-by the lens when .an exposure of a negative is caused to take place.l At substantially all times when a nega- \tive is not beingexposed the image projected by the lens is reflected in focus on ground glass II by means -of mirror I2. The lens is I3. Said image may be observed by the operator of the camera driftsight through window I4 in conjunction with mirror il, which is supported by a portion" of the camera driftsight housing enclosing the chamber It that functions as a viewing hood.

The reflex camera shown is, therefore, essenvided with suitable View nders, orvdriftslghts,

tially employed as a driftsight, and the navigational method herein disclosed is, therefore adaptable for useingconjunction with any driftsight which provides an equivalent means for '30 viewing an earth object or an image of the earth,

herein for convenience termed the earth image." For reasons before set forth herein'levelling of the camera driftsight is imperative, and

isaccomplished in conjunction with reference to.

level bubble Il, see Fig. 1. The principal axis of the'intervalometer cau'sesthe occurrence of the to be synchronized with the velocity of motion of the image on the ground glass.

' ground glass between exposures to enable the operator to manually trip the camera mechanism at intervalsof 'time corresponding to the travel.

exposure of a negativeysaid means being adaptedl lens Il is in a vertical position when the camera is properly levelled.

lThe bottom of the aircraft incorporates an opening of suiiicient size to clear the neld of light 40 included within the angle covered by lens IQ., sufof the said image. between two lines defining said v distance. Means are also provided to adjust the location of one of said lines to vary said distance in accordance with the amount of picture overlap desired. i

The camera driftsight herein disclosed, incorporates means whereby, when thecamera is being automatically controlled by the intervalometer mechanism and the interval of-time between the occurrence of exposures is determined there- .ilcient clearance being provided to allow for the normal amount of motion'o'f the camera driftsight with respect to the aircraft occasioned by levelling the-driftsight. The lens is preferably 4s centered over said pening when the longitudi- Said ground glass Il is preferably disposed in a vertical plane, or parallel to the principal axis by, a warning of each impending exposure is sure and, further is enabled to change the orienwjl, which is suitably guided by tation of the radical axis of the camera with respect to the longitudinal axis of the aircraft fuselage at a time 'whichwill least interfere with of lens Il, and is supported in a iixed position partly by means of a portion of the camerahousing Ii and strips. I'I, which are attached to the said housing by means o'f screws,.see Fig. 13. v

Referring to Figures 13 and 16, shaft I8 is driven by means of a conventional intervalometer mechanism I! and is journaled in bearings I Sa. Said shaft incorporates a roller 20 which`is xed to shaft Il and drives a transparent endless belt rollers 22 which turnfreelyinbearings 23.

One side of said belt 2I ls sufficiently close to ground glass II to cause lines 2t on said belt 2| to be clearly visible through said ground glass Il g5 and to appear to be superposedfon the earth the stabilized condition of the aircraft and the levelled condition ,of the camera at the time of the occurrence of an exposure. The pilot'of the image. 'I'he other side of said belt is at a sum- .cient distance from groundglass Il to cause the lines 24 on said belt to be so indistinct that they `are substantially invisible. The thickness of said ,belt 2| is made such that the refraction of the light passing through it does not materially affect the focus of the limage on ground glass I I.

Asthe aircraft moves forward the image on ground glass I I will appear to travel from the top `1s of said ground glasslto the bottom thereof, and

Images