military cartographic camera calibration

8/14/2019 Military Cartographic Camera Calibration

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.I EII)I I)I IIm THE CALIBRATION OF MILITARY III 0I CARTOGRAPHIC CAMERAS II IIII

byIi

Robert M. Spriggs

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FIELD OFFICE

U . S . ARMY ENGINEER GEODESY, INTELLIGENCE

AND MAPPING R . & D. AGENCY

T e c h n i c a l N o t e 6 6 - 2

- - - - - - - - -THE CALIBRATION OF MILITARY

CARTOGRAPHIC CAMERAS

R o b e r t M. S p r i g g s



The f i l e s of th e GIMRADA Fie ld , Of f i ce conta in ca l i b r a t i on

ce r t i f i c a t e s fo r a l l mi l i t a ry ca r tographic cameras developed by

the U. S. A i r Force . I n t h i s repor t , t he au thor has ex t rac t ed

per t ine nt information f rom these ce r t i f ic a t es and has presentedth is information in a formwhich should be of a considerab le value

t o personnel i n map and ch ar t production.

M r . Robert Spr igg s, who authored the rep o rt , and Mrs. J e r r i

Amos, who performed t h e ty pi ng , des erv e much cr e d i t f o r t h e work

involved i n the ext r ac t io n of da ta and i n the prepara t ion of th e

repor t .

This technica l note i s one of a ser ie s publ ished i nt er na l ly

by GIMRADA Fie ld Office and disseminated t o suppo rt mil i ta ry mapping

development by t h e Department of Defense.

ROBERT G. LIVINGSTON

Chief, GIMRADA Fie ld Off i ce



TABLE OF CONTENTS

4

I. INTRODUCTION . . . . . . .11. MAPPING CAMERA CHARACTERISTICS . .'. . . . . . . .111. CAMERA CALIBRATION REQUIREMENTS . .,. . . . . . .IV. CALIBRATED FOCAL LENGTH, EF FE CT IV E FOCAL LENGTH . .

V. D I S T O R T I O N . s . m . m . . . . . m . . m . m m . .

VI . CAMERA CALIB RATI ON METHODS AND EQUIPMENT . . . . .V II . RE SO L U T IO N

. . . . .V I S I . CALIBRATION DATA FOR MAPPING CAMERAS . . . . . . .IX. BIBLIOGRAPHY . . . . . .Xe A P P E N D I C E S m o m . o . . e m . m . . . m . . m . .

A. T y p e T - 1 1 C a m e r a D a t a . . . . . . . . . . . . .B. T y p e KC -1 C a m e r a D a t a . . . . . . . . . . . . .C. T y p e T -1 2 C a m e r a D a t a . . . . . . . . . . . . .

Page



4

LIST OF ILLUSTRATIONS--Figure Subject Page. . . . . . . . .. The Type KC-1 Mapping Camera 2. . . .. KC-1 Camera with Film Magazine Removed 2

3. Field Camera Calibration Range at WPAFB . . . . 4

4 . Multi-Collimator Bank Distortion Calibrator . . 5

5. Wild Type T-4 Goniometer . . . . . . . . . . . 7



4

THE CALIBRATION OF MILITARY CARTOGRAPHIC CAMERAS

I n t r o d u c t i o n :

The accuracy of p ho to gr am et ri c mapping methods depends i n pa rt

on th e qu al i t y of th e camera used. For th i s reason photography in-

tended f o r photogrammetric mapping must be tak en wit h a camera desig ned

f o r t h i s p u r p o s e .

11. Mapping Camera Characteristics:

The mapping camera must, (1) have a le ns designed wit h de f i n i t e

d i s t o r t i o n c h a r a c t e r i s t i c s a nd, (2) be a r i g i d n ie chan ic al s t ru c t u r e

which ho lds t h e l e n s , f i du c i a l marks a nd foc a l p l a ne i n a f i xe d o r i e n t -

a t i o n s o t h a t d im en si on al i n t e g r i t y w i l l be maintained. A t y p i c a l

mapping camera ( t h e Type KC-1) i s shown i n Figu res 1 and 2 .

111. Camera Ca li br at io n Requirements:

Cameras a r e c a l i b r a t e d t o de te rmine t he p re c i se va lue o f t he

c a l ib ra t e d foc a l l e ng th , t he ma gn itude o f t he ra d i a l and t a nge n t i a l

d i s t o r t i on , t he pos i t i on o f t h e f i du c i a l marke rs a nd o the r d ime ns ions .

The ma nufa c tu re r pub l i she s c a l i b ra t i o n c e r t i f i c a t e s fo r e a c h ca mera.



Fig. 1 The Type KC-1 Mapping Camera



V. D i s t o r t i o n :

D i s t o r t i o n i n a l e n s r e s u l t s i n a change i n s c a l e o ve r t h e

p i c t u r e a r ea . D i s t o r t i o n g e n e r a l l y i s expressed i n polar coord inates

a s r a d i a l o r t a n g e n t i a l d i s t o r t i on .

A. R a di al d i s t o r t i o n ; o f t e n r e f e r r e d t o a s l l d i s t o r t i o n , l l i smade up of two components, sym met rica l and asy mm etr ical . Symmetrical

d i s t o r t i o n i s a c h a r a c t e r i s t i c of t h e l e n s d e si g n; i t s e f f e c t c a n

be minimized by cor rec tor p la te s when the negativ es ar e prin ted nrby using cams on the ste re op lo tt er . Asymmetrical d is to r t io n (ofte n

c l a s s i f i e d a s p ri sm e f f e c t ) i s a proper ty of le ns manufacture induced

by th e decenter ing of one or more of the lens elements, by i rr eg ul ar -

i t i e s i n th e sur faces of th e lens elements , and by t ipp ing of t he

f o c a l p l an e w i t h r es p e c t t o t h e l e n s a x i s .

B. T a n g e n t i a l d i s t o r t i o n is a function of ' lens manufacture and

i s caused by the prism ef fe ct . The axi s of maximum ta ng en ti al d is -

t o r t i o n u s u a l l y w i l l be 90° from t h e a x i s of maximum asymm etri cal

r a d i a l d i s t o r t i on .

V I . Camera C a li br a ti on Methods and Equipment:

Cameras a re c al ib ra te d by e it he r of two methods - photographic

o r v i s u a l .

A. The photographic method i s th e most des ire d and can be ac -

complished on a f i e l d range or by use of a m ulti coll ima tor bank.



Fig. 3 Field Camera Calibration Range at Wright-Patterson AFB, Ohio.



Fig . 4 Mult i -Col l imator Bank Dis to r t io n Cal ib rato r (Perk in-Elmer)

.: -..,-h..,,&.~~&..:A: i<;g:?%r>.:. . , ~. . . ; . .@". ' - ." . . . . ."> "& 3 :.a. .:-

. .. if,:;--. <,:. i - : 5 :. * . ... . . , ,, ~ ",. ... .',.. .- ~. 7 " . i



image and the t ar g et image a t each ang le i s measured with a comparator.

R a di al d i s t o r t i o n i s th e di ffe ren ce between t he computed dist an ce and

th e measured d is tan ce t o each ta r ge t image. The point of symmetry i s

d etermined by making th e d i s to r t io n t o th e l e f t i n d r i g h t o f th e ax i s

symnetr ica l . The ca l ib ra t ed foc a l leng th i s computed and th e di s to r t io n

i s a d j u st e d t o t h e c a l i b r a t e d f o c a l l en gt h.

44. The tange nt i a l d is to r t io n i s measured fo r each d iagonal

on t h e t e s t p l a t e .

B. Visual methods may lead t o d is to r t io ns which ar e d i f f e r en t

i n magni tude than th e d is to r t io ns recorded photographica l ly because

of l a t e r a l chromatic ab er ra t i on in the camera lens . The proper l i gh t

s o ur c e a nd /o r f i l t e r s sh ou ld be s e l e c t e d s o t h a t t h e s p e c t r a l s e n s i t -

iv i t y of t h e ey e i s matched t o t ha t of photographic films .

1. Goniometer method: An a c c u ra t e ly c a l i br a t e d t e s t o b j ec t

on g lass is p laced i n th e fo ca l p l an e and i l l umin a ted in a d i r ec t io n

toward th e le ns . The camera i s s e t on th e goniometer (See Figure 5)

s o th a t t he a xi s about which the angles ar e measured passes through

th e cen t er of th e en t rance pupi l of th e lens . The te lescop e of th e

goniometer i s p o in ted a t su ccess iv e p o in t s on th e t e s t o b jec t and th e

f ie l d ang les de termined. From the fo ca l leng th o f the l ens be ing

te s t ed and th e ca l ib r a t io n of t h e t e s t o b jec t , t h e an g le s su bten ded

by the var io us p oint s on the t e s t o bje ct can be computed. The dis-

t o r t i o n i s computed from the d iff ere nc e i n angles on the obj ec t si d e

and image si de of th e lens and converted t o th e sta ndar d form.

C. Some work has been done an s t e l l a r ca l i b r a t io n of b a l l i s t i c

cameras. The s t a r f i e l d i s photographed on a g la ss p la te i n the

fo ca l plane of th e camera. The po si t i on of each s t a r i s measured



F ig . 5 bii ? t i ?'y:.,-, ; c : . ~ ~ ! - c r, ,



radiu s drawn from th e cen ter of t he format and tan ge nt ial re so lu t io ni s measured wi th t he l in es perpendicular t o th e radius . A s i n g l e

average va lue f or re so lu t ion i s determined as the area-weighted

average resolut ion (AWAR) by dividing the format in to concent r ic

annu lar zones. The ar ea of each zone lyi ng wi th in the format i sused i n de termining the weight ing r a t io . The squ are roo t of th e pro-

duct of t he r a d i a l a nd t a r g e n t i a l r e s o l u t i on i s computed for each +

zone and mu lt ip l ied by th e zone ra t i o t o ob tain t h e zone-weighted

resolut ion. The AWAR i s th e sum of t he zone-weighted re so lu tio ns .

VIII. Cal ib ra t ion Data:

The ca l ib ra t io n da ta fo r th e mapping cameras , l i s te d i n the

appendices , was ext r ac ted f rom the camera ca l ib ra t io n ce r t i f ic a t es

issue d by th e manufacturer. Some of the cameras have been overhauled

and reca l ib r a t ed and the da t a f rom each ca l i b ra t i o n ce r t i f i c a t e i sl i s t e d .

The probable e r ro rs of th e ca l i bra ted f oca l l engths a re :

T-11 0.100 mm

CA- 14 0.100 mm

The probable e r ror s o f t he d i s t o r t i on s a re :



1. "A History of Military Mapping Camera Development," Robert G.

Livingston, Photogrammetric Engineerinq, ~01'.XX, No. 1, 1964.

2. "A Simplified Method of Locating the Point of Symmetry," F. E.

Washer, NBS Report 4273,:August, 1955.

3. "American Mapping Cameras," rs. Clarice L. Norton, FairchildCamera & Instrument Corp., Paper delivered at the X Congress,International Society of Photogrametry, Lisbon, Portugal,September, 1964.

4. "Calibration of Precision Airplane Mapping Camera," F. E. Washer& F. A. Case, J. Research NBS 45, 1 (1950) RP 2108, -Photogrammetric

Engineering, Vol. XVI, No. 4, September, 1950.

5. "Calibration of Surveying Cameras," Brig. M. Hotine, RoyalEngineers, London, 1929.

6. "Calibration of Survey Cameras an6 Lens Testing," D. E. MacDonald,

XVII, 363 (June 51), Photogrammetric Engineering.

7. "Correlation of Data from Various Methods of Aerial Camera Cali-

bration," Robert M. Spriggs, Paper delivered to X Congress, Inter-national Society of Photogrametry, Lisbon, Portugal, September,1964.



. .'a,i n .rr:;:$doc,,il."..;; 13.

"Evalua t ion of D is t o r t ion by the Inver se Nodal Sl id e ," F. E.

Washer, NBS Rep ort 4690, May, 1956.

14. "Field Camera ca l i br at io n, " E. L. Me rr i t t , v L ~ . IV , 303 (June,

1948), Photogrammetric Engine ering.

15. "Field Ca li br at io n of Aer ia l Mapping Cameras," Eldon D. Sewelt ,

Photovrametr ic Engineer ing , Vol . I V Y No. 3, Septemb er, 1948.

16 . "Field Res olut ion Te st s with t he Metrogon Lens," EldonD.

Sewell& Robert G. Livi ngs ton, Report 1176, Engineer Research & Develop-

ment Laboratories, August 4, 1950.

17 . "High Perfor mance Mapping Equipment and M at er ia ls ," L. W. Crouch,

Photo gramme tric En gin ee ri ng, Vol. XXVII, No. 1, March, 1961.

18. "Improving A e ri a l Mapping Photography," Eldon D. Sewell, Photo-

g r a m e t r i c Engineerinq, Vol. XVIII , No. 3 , June, 1952.

19. "Interpretation and Use of Lens Tests and Camera Calibration, '!

I . C. Gardner; 111, 13 (March, 1937), Photogrammetric Eng ine erin g.

20. "In st ruc tio ns f o r Ca li bra t i ng Ae ria l Mapping Cameras on t he Fi el d

Range a t WPAFB," Rob er t M. Sp r ig gs , CMSgt., USAF and Ro be rt G.

Livingston, Lt . Col. , CE, USAR, Wrig ht A i r Development Div .

Te ch ni ca l Note 60-267, November, 1960.

21. "Locating th e P ri nc ip al Point of Pr eci s ion Airplane MappingCameras," F. E . Washer, J. Res ea rc h NBS 27, 405 (1941) RP1428.

22. "Manual of Photo granwe try," American S o ci e ty of Photograrmnetry,



27. "Resolution, Distortion and Calibration of Air Survey Equipment,"

L. E. Howlett, Vol. XV I , 41 (Mar SO), Photogrammetric Engineering.

28. "Sources of Errors in Various Methods of Airplane Camera Cali-

bration," F. E. Washer, NBS Report 2534, June 1953, Vol. XXII,

727 (Sept 56) Photogrammetric Engineering.

29. "Star Exposure Method of Camera Calibration," Report No. 131-50,

Photographic Interpretation Center, Department of the Navy.

30. "The Aerial Camera," Clyde E. Berndsen and Robert G. Livingston,

GIMRADA Field Office, Technice? Note 64-1, April, 1964.

31. "The Calibration of Air Cameras in Canada,'' RH Field, Vol, XII,

142 (June 46), Photogrammetric Engineering.

32. "The Fairchild Precision Camera Calibrator ," 'C. L. ort ton; Vol.

XVI, 688 (Dec 50), Photogranmetric Engineering.

33. "The Significance of the Calibrated Focal Length," I. C. Gardner,

Vol. X, 22 (March, 1944), Photogrammetric Engineering.

34. "Tangential Distortion and Its Effect on Photogrammetric Extension

of Control," John Pennington, Photogrammetric Engineering, Vol.

XIII, No. 1, March, 1947.

35. "Tangential Distortion in the Metrogon Lens," Robert G. Livingston,



151.16 - -

52-009.- . -- .- - - - -- - - 52-009

152.43

52-011

52-012

52-013- - - - . - -

52-015--- - -- . --.- -

-52-017- - -.- - -

52-019

5;-020- - . -- A - -. --

52-021- -- . --52-022. -- -

52-023

5P-024

52-026

52-027- -52-027--

52-028- - .. - -52-029

52-030 52-030-52-031

52-032 153.26-- - -

52-033 153.27

52-034

I F -W I CJUl I4 100 *



1 11 CAMERA (Cgq'2 )

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--- - --52-077

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5 2 -0 8 0

5 2 -0 8 1

52-082

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T-11 CAMERA (CONT'D) f~.F;.RA -r-- 1- pmx FCEL ~ ~ ~ ~ ~ - ~ - ~



1-11 CAMERA (CONT'D)



T-11 CAMERA (COW'D) a



T-11 CAMERA (CONT'D)

54-2131

54-215

54-2171 - -AS-WP S JULU %E



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T-11 CAMERA (CONT'D)



T- 1 CAMERA (COW 'D)

-- TENS - I1 gq

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T-11 CAMERA (COK'D)



T - l l CAMERA (CONT'D)

54-442

54-447

54-450

8



T-11 CAMERA ICONT'D)



T-11 CANERA (CONT'D)



T-11 CAMERA ( ~ o m ~ ~ )--- --1 G~T - LENSX L

DF7327

DF7273

- --

- - -

DF5181

54-618 --RF5611

U-WI-cNL U

y-11 CAMERA (COW'D)- -



B N S L - - TANG - G- 1- 7.50-1e1 '1 -- 4 : -1 ~ l s2- l ---T - I



KC-1 CILlRA (1) CaliUration Certificate Obsolete - New Certificate 18sued. (2) Recalibration Certificate - Previous Certificate Obsolete.



KC-1 CAMERA (CONT'D) -



- -- A -

3-099C 5

53-100 [

3-106 1 -I

: . - - __AFWI-CJUL M ZOO



I F - W T 8 JVL U



K C - 1 ~MRA (1) Certificate Bbsolete - New Certificate Issued (2) Recalibratidn Certifi cate - Previous Cert. Obsolete (3) No Platen Calibration Certr ficat e- --

-59-004. - - --

152.563 .OM

- -59-010

59-011

59-013

59-015

59-020 -59-021

55-026

59-028



KC-1B CAMERA (CONT'D)-

CFL- - - - -

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-- -151.228

152.311-- - -151.019--- --

151.489- --- -151.237



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+.009 +.007

+.OM +;-or07+.008"it+.OM

-- -



CA-14 CAMERA . I MAR IDA= 7.5' 15' 22.5O 27.5' 1 30°

i 2 m 3 7 F / k T - q-- - -- - - -- - -A - -- -

CA- 4 CAMERA (CONT D)



THE CALIBRATION OF MILITARY

CARTOGRAPHIC CAMERAS

TECHNICAL NOTE 66-2

ADDENDUM NUMBER 1

Robert M. Spriggs . -



FIELD OFFICE

U. S. ARMY ENGINEER GEODESY, 3ibllTLLXGENCE

AND MAPPING R. & D. AGENCY

TECHNICAL NOTE 66-2

ADDENDUM NUMBER 1

TRE CALIBRATION OF MILITARY CARTOGRAPHIC CAMERAS

by

ROBERT M. SPRIGGS



ADDENDUM NUMBER 1

TO4 ,a

''THE CALIE?2AW'ri~RF MILITARY CARTOGRAPHIC CAMFRAS"

TECHNICPA NOT& 6 5 = 2L

1. A.ddi tiona1 cal ibr at i on ce r t i f ic at es for car tographic cameras i n

the USAF inven tory have been re ce ive d by th e GIMRADA Field Off ice . Soate

of th ese cameras were developed fo r rese arc h purposes; t he ref ore ,Appendtx G i s added t o inc lud e cameras which a r e not made in production

quan t i t i es . Many of th es e cameras were developed by modifying KC-1

cameras.

2. The KC-6A camera i s des igned and produced s pe ci fi ca ll y f o r th e

USQ-28 mapping and ge od et ic subsystems. Two cameras ar e in s t a l l e d i n

each system. The cameras have many f ea tu re s t h a t were not found i n

previou s mapping cameras i n t h e A i r Force inventory:

a. Platen reseau, 25 points

b. Image motion compensation

r - --c . Ve rt i ca li ty read out re fer en ced t o the,_-Hiper-* 11

In e rt ia l R-eference Unit

?. Synchronous operation of two cameras

e . ~ u t a m a tc Exposure Con trol

to the ri gh t of the page. The maximum radi al d is to rti on in the format

of each camera is included for your information.



..

; 7

d . Appendices F and G are new additions to the report..'

R . M. Spriggs



- -TECHNICAL NOTE 66-2 ADDENDUM T-11 ClWZRA

APPENDIX "A"

:*APPENDIX "B" .



,yf ::::?xA>'. ... -. CAMERA- DATE-

9/25/61 Deleted from Inventory - Modified to

KC-3 camera.

8/3/61 Deleted from Inventory - Modified to

KC-3 camera.

3/27/63 Deleted from Inventory - Modified t o

KC-& 63-1001 ;



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Maximum Maximum

Asymne t r y am Distortion arm

Maximum

Asynnne t r c

Maximum

Distortion m



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4 .010

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.013

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.014

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.011

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military cartographic camera calibration

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