DE1623475A1 - Photogrammetric method - Google Patents

Description

Kassel Institution, Vaduz (Liechtenstein)

"Photogrammetric method"

In recent years, photogrammetric instruments, which are referred to as orthoprinting devices (or orthoscopes) are becoming increasingly important.

The general task of such instruments is to record a record which always contains errors the inclination of the recording camera or the topography of the ground to another form of photography to implement, namely in the so-called. "Orthophotography", which contains essentially all the details of the original image taken from the aircraft, differs from this, however, in that the details are registered in their exact position.

In general, the orthoprinting devices can be of two types Groups are divided into electronic and optical orthoprinting devices.

The electronic orthoprinting devices use a device such as Closed circuit television ("closed circuit television") can be referred to while the optical

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Orthographic printing devices use optical means to transfer the image. Both groups of orthoprinting devices use the principle of breaking the photograph down into narrow, parallel strips while simultaneously doing them a small differential part of the photograph transferred and corrected so that the same on a photographic one Disk can be registered in its correct form.

The accuracy limits of both electronic and optical orthoprinting devices are based on the fact that the image element that is transferred and corrected is always limited in size, but the corrections made are only perfect if the topography of the ground does not vary greatly within the limited area to be transferred Picture element it has. It appears that the electronic orthoprinting devices have the advantage of being able to rectify the picture element in a relatively easy manner, so that it ^{corresponds to an "extremely good fit plane 11} " which approximates the area of the picture element.

This plane can either be horizontal or run at an angle. In the case of optical orthoprinting devices, only a horizontal plane can be used as an approximation. This difference is from an economic point of view seen of great importance, Ua Jie electronic

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Orthographic printing devices can use a larger picture element if the final accuracy is the same, which is why they can convert a photographer into a orthophotography in a shorter period of time ",. * . - ", ■:

On the other hand, the optical printing devices have orthoprinting devices the advantage of orthographies with a greater ability to decompose and, as a result, with a better quality and higher To generate benefits.

The purpose; of the present invention is to perfect the optical orthoprinting devices in such a way that that in most practical cases they allow an image to be broken down into strips of greater width. This allows orthographies to be carried out more quickly with optical means, without the image sharpness or the accuracy to affect.

The device according to the invention is primarily Can be used together with a special type of optical orthoprinting device, but it can be used with other optical Crthoprinters, especially those with an anterior image, are advantageously used.

The inventive optical orthoprinting device with a front image is characterized in that the geometric errors are reduced by performing the orthoprint using line elements which are rotated during the transfer of the photographic to the orthoprinting device and reduced to an appropriate scale. "-.:■■ ^r

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1BH3475

Further advantages and features of the invention result from the description of an exemplary embodiment based on the

Fig. La - Ib show the scheme of a rotary pressure device according to Br * Parenti (for the calculation of to which the invention relates.

In Pig »2 is the. Detail of the servomotor shown *

The scheme illustrated in Fig * la must be used as in the Points 4 and B are considered combined with the scheme shown in Fig * Ib * It is of the greatest importance that in the instrument according to the invention, the image element, which needs to be transferred and corrected from the image of the filament of the illumination lamp is blanked. The image of the thread is greatly diminished, so that its Width is very small (about 6 * 1 this width is so small * dags because of what can be achieved in practical work Decomposition and the achievable accuracy may be said * that the device is more of a line? as a surface element transfers> like the latter with the others Orthographic devices in this case *

The general idea of the invention is that by linfiihruftg of Drehänderungs- and Maßstabänderungskprre-kdas Miiienelemeiit such corr-igiertwird) that it depicting # ll% _f liel ^ he gemäSB "eiiaer feesteii

fe isii | da, isieB Hermal makes it possible der Se: iimi | gkeit imd Me iphöiWiftg der

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speed of the orthoprinting device according to the invention. In the diagram of FIG manual setting. The point further down on the left and ^{labeled »z tu} indicates the arrival of the" Stereovorreisser ¹¹ ("stereoplotter") »The point below and ^{labeled" x 1} ", which is enclosed in a square means the servomechanism coupled to the "stereo tab". The point below and ^{labeled "y * n} ", which is enclosed in a square, represents the servomechanism ¹¹ connected to the "stereo tab. The square on the right that contains" tgi <"means the "Servomechanism of tgixT", while the line proceeding from the same to the right represents the "exit of tgoC.

The immediately below exploiting Dende triangle represents the "servo amplifier." In the scheme of Fig. Ib, the left with "designated Γ ~ Λ" point, the manually taking place setting is ^1, while the right with ^"w f ^l * Marked square the Servomechanism of " -f " and * the line going out to the right from the same signify the exit of "^", while the triangle immediately below represents the "servo amplifier". The mathematical "off"""

press for the required rotation and scale changes according to 109820/0251,

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of the invention can easily be obtained by starting from the basic equations of analytical photogrammetry, namely: - -; ■; · ■; ·, -:,;,: '? "- · = ■ .-: ■; ^ i: ' ^ -: -;: ^%: yh ^ s-- ■ / ■:.,.} ^ .-.

^a ii ^{xt + a} 12 ^; 'i · ~ - ' ^{έ: a} 31 ^{X1 + a} 32 ^T ζ « a _2l l ' ^r -f "Ζ * ' ^{1 + a} 33 ^r . ^: t " ^a 23

I = - X

a _3l X ^T. + · ., Zy ₂ Ϊ '■ ■

the image coordinates are:. . -.

X ^f , Y ',, Z * are the coordinates of the kodelies (with - "referring to the nadir);

f is the Fokalliaige *.,., .. _,

/ \ is the scale factor from the photo to the kuster a _{n η} is the function of the K ^ mera rotations 7, QJ , yC

These formulas are simplified / if the scanning of the .Pho-to ₄ graphie._in ,. is carried out regularly by following lines which are parallel to the Acti.SA. 4 run ,, .. and if the angles /, G) and ^ f are small ,,,,, yj ^ y & xxiss -.,. is a valid requirement for almost all practical cases. One obtains ti-ann: ... "'''■ -? ■' ^τ · ■ ·. _.

f-λ

y ^ lä25ΐ "

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this

greater

Θ "Ζ *

BY -. , f. [Λ · f

Γ) ν '/ * 7 / V

At Äbteqtuftg, for example. Zerlegutig t in the IGT ßicbtüsig

where K did a coefficient that of the slope of the model in llielitting Y

diteer 0 | hurry lit to notice:

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X * remains constant for each sample or
Cutting strips;

I »changes regularly:
Z ^? and K change in a random manner.
The angle of rotation ( ni /) of the line element can be expressed as follows:

cL = arc tg y

dx
Nevertheless, it is advisable to use the following expression:,

{L \ j- _ _ / ■ _ dy

O; tg ck * ^β

dx

Similarly, the scale factor ^ C can be expressed as follows:

The practice of the invention can be divided into two parts:

1) Calculation of tgoC and

2) Elaboration of the optical devices which are suitable, the required rotation and the required scale
to create.

The computational problems related to the present invention are not difficult to solve for those skilled in the art have experience in the field of electronic computation. One can prove that the value of tg <? C depends on the geometry

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of the aerial image and of the inclination of the palpable ground (dead space) on one. Value that is less than 1 (one).

For the same reasons, the scale ^ can be between 0.7 and vary, although a much smaller change will suffice for many practical applications.

For these reasons it can be proven that a calculation accuracy of about 1% is sufficient to achieve very good results. This accuracy can be achieved by means of analog electronic calculations. From an economic point of view, the problem of the calculation can be solved in an expedient manner by making use of the fact that the input variables are already given as shaft rotations in order to control the scanning displacements of the orthoprinting device, and that the output for the purpose of Actuation of the optical devices must also appear as shaft _{rotation 0} These two facts can be appropriately used in the calculation in order to save numerous calculation steps.

The values for / S, X ⁵ disappear from the end formulas-

Daa diagram la - Ib illustrates a block diagram of a preferred for this calculation analog computer _o Of course, those skilled in the field of electronic analog computer numerous other embodiments

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planned and designed that implement the principle of the present invention. The optical devices required for realizing the rotation and horizontal bar change of the line element are ^{already present in the ortho printing device to which the inventive T} / Ervollkoniirinuu £ is to be attached. These optical door directions consist of the following parts:

1) Off putty to rotate the lamp around the optical acnso the orthoprinting device u: -i an angle .. <,.

2) From putty to compensate for the rotation by means of a

Dove prism As the Γ image transmitted through a Dove prism rotates twice as far as the prism itself, must be

, Prism one at a time. Kinkel ⁰ ^ be rotated.

3) From a lens system with variable focal length, a so-called "zoom", to change the ί ·. ate it from the line element transferred as a function of - ¹ P.

Since the mechanical-optical gowns are already present in the orthoprinting device, the description of the gowns is sufficient to convert the large tg JLr into a rotation oC o A mechanical realization of this function

2
is shown in FIG.

The mechanism consists of gear rings 1-2, which such are assembled together «that when a ring is rotated, the other turns in the opposite direction. These rings are mounted around two rotatable cylinders, so that when a ring is turned, the corresponding one is also turned

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Cylinder rotates around its axis. In the end connected to the ring cylinder 1, a lamp 3 is accommodated such that its filament passes through the axis of the cylinder itself. In the cylinder connected to the ring 2, a Dove prism 4 is mounted, the longitudinal axis of which coincides with the axis of the said cylinder. The ring 1 is provided with an arm 5 which has a longitudinal slot 6 in which a mandrel 7 is arranged, which is attached to a cutter 5 which in turn is actuated by a control screw 9. The rotation of this screw is carried out by Servouechanisnius tgcX. «10 and is therefore proportional to t £ csS. -

It is obvious that when the cutter moves and thereby moves away from its position Ό by a value equal to tg.; £, the ring turns 1 uiü an angle pC. If the diameter of the ring 2 is twice larger than the diameter of the ring 1, the Dove prism is rotated through an angle cC.

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Claims (1)

ί. Photo-graphical method, especially for optical orthographic back devices with front UiId _f, characterized in that, to reduce the geometric errors, the orthoprint is carried out by means of line elements , which are rotated during the transfer from the photograph to the orthoprinting device and reduced to a suitable scale « 2 · Method according to claim 1, characterized in that the twist and wet bar corrections from an electronic one Analog computer are calculated « 3 «Device for carrying out the method according to claims ί and 2 :, .. characterized in that to convert the magnitude of ig ot <in rotations oL and 'g fc"" two interlocking and therefore rotating in opposite directions gears or" Gear wheels are provided> the diameter of which has a ratio of qC / oC to each other, ■■ ι ■■ :: ".-: ^■: ■■■ - ² wherein the first gear | contains, while the second gear | | 1) on its axis the filament of a lamp {3 2j on its axis a Dove -Prism. Contains and. The rotation of the first gear wheel is generated by an arm (5) | which with a slot (6) guides a small pin or mandrel (7) which is firmly connected with a screw nut (8) which is displaceable by a screw | 9ί controlled by the servomechanism for tg oC (10) proportional to ig ^ C « BAD ORIÖINAt ^ i ₂ -