PROF. J. E. COLCORD*

University of Washington

Seattle, Wash. 98105

A Survey of Training AidsResults of a questionnaire circulated amongthe schools teaching photogrammetry.

li

JN'I'RODUC'I'IO~

D URI~G THE PAST years there has been anincrease in the complexity and sophisti­

cation of equipment and in the applications ofphotogrammetry both in practice and ineducation. The papers by Merchant,' R. H.Brock? discuss the trends and show the majorcourse offerings. There are still many schoolswho have minimal courses and who utilizeobsolete procedures and equipment. Onepossible way to assist the school operatingwithout modern equipment or funds to ob­tain it is through the use of inexpensivetraining aids in the form of films, slides,stereog"am sets and models. Jt would ap­pear that the less photogrammetry offered

that offered at the University of vVashington3

or Purdue, or by full use of Sabbatical andfellowship programs now available, however,the status of training aids is still important.

NEED FOR THE SURVEY

vVith this increased awareness in photo­grammetry came an increasing inquiry to theEducation Committee of the AmericanSociety of Photogrammetry (ASP) regardingtraining aids. As Chairman of this committeein 1966, the mandate to take on this work wasinherited from some of the recommendationsfrom Professor Baker. This appeared to be afeasible project that may be of value, so,in consultations with Prof. Bruce Stanton,

ABSTRACT: The ASP Education committee has recently conducted a poot by useof a questionnaire of about 350 institutions, firms and faculty about the use ofand need in tmining aids. Based on 23 percent repty sampte the results areshown in this paper, including a list of commonly used tmining aids.

the more these aids are needed. This is not,however the apparen t case. One reason maybe the lack of knowledge of availability ofthese items. It is certainly true that a picturecan not su pplan t good teaching and or aprofessionally qualified teacher and they donot solve a problem needing mathematicalor physical laws. They do, however, show thestudent the modern state of the art and allowhi m to relate his pl'actice and theory to thereal world. They are, of course, especiallyvaluable in the hands of the knowledgeableteacher. It is hoped this last facet can beaided by attendance at the institutes such as

* Submitted under the title "A S"rvey of Train­ing Aids used in Teaching Photogrammetry."

I "A Survey of Courses Offered in Photogram­metry", D. C. Merchant, PHOTOGRAMMETHICENGINEERING, Nov. 1963.

2 "Courses Available in Photograml1letry", R. H.Brock, PHOTOGRAMMETRIC ENGINEERING, Mar.1966, and Addend"m, Sept 1966.

the vice-chairman, a question naire* was de­signed. This questionnaire was distributed toabout 350 individuals, Universities, andfirms known to or presumed to be interestedin training and education by Mr. C. E.Palmer of the National Headquarters of ASP.

As of February 1967 there have been 80 re­turns, or about 23 percent. This is consideredto be a satisfactory sample even though onlya small proportion of the respondents had anyfactual data or ideas.

MOTION PICTURE FILMS

As would be expected, the greatest informa­tion obtained concerns 16 mm. movies. Themotion pictures used by the responden ts areshown in Table 1. The results show that most

3 "A New Approach to Surveying Education,"J. E. Colcord, PHOTOGHAMMETRIC ENGINEERING,Nov 1963.

* ..or editorial rea'ions, a copy of the question,"aire is not reproduced here.-Editol'.

291

292 1'1I0TOGRAMMETRIC ENGINEERING

TABLE 1. ASP EDUCATION COMMITTEE TRAIKIKG r\IDS QUESTIONNAIRE SUMMARY

JIt[otion Picture Films (16 mm. Sound for use in Undergraduate & Graduate in Geometric 1'holo­gramll1etry & Image Interpretation) All are available on loan. See Appendix for addrejses and cOll1ments.

SlIi/ability Rali"g NeedsItem.\'0.

Title B/W Color

RunTimeMin­utes

Dale M ode A vailaole /roll/Ex. Cd. Fair

.~Iodern;:a­tio"

Le"eling for Topographic Map­ping

Transi t Traverse for Topo­graphic Mapping

Triangulation for TopographicMapping

Supplemental Control for TOIXl­graphic Mapping

The Preparation of TopographicManuscripts for Reproduction

6 Negative Scribing for Map Re-production

7 Tellurometer8 ABC System9 Helicopters as Aid in Alaska

Surveys10 Topographic Mapping by Photo- X

gram metric Methods11 Introduction to Photo-Interpre-

tation12 Aerial Photo Interpretation of

Hydrological Resources13 Aerial Photo Interpretation of

Forest Resources14 Aerial Photo Interpretation of

Geological Resources15 Aerial Photo Interpretation of

Soil Resources16 Paving the \Vay to Progress

17 ~Iaking Mars the Efficient \Vay

18 Introducing Phologrammctry

19 Super \Vide Angle Phologram-melry

20 Navy Photography in Intelli-gence

21 From Jennies to Satellites X22 Terrain [nvesligation Tech-

niques23 Photography in the USAF X

(SFP 1028)24 Multiplex Mapping, T, [[ X

(TS-5, 194Q; 1546)25 The Giant Step (SEP 144'1)26 Mapping for Defense

27 Cameras Above, Secrets Below X28 Fundamentals of Optics X20 McBride Photo-Interpretation X30 The Airborne Magnetometer X

X 20 1951 USGS X

X 25 1951 USGS

X 30 1Q53 USGS

X 25 1952 USGS X

X 30 1952 USGS

X 24 1953 USGS

X 12 195Q USGSX 12 1964 USGS XX 12 USGS

90-120 USGS X

X 22 1960 USGS XX XXX

X 39 1960 USGS XX

X 39 USGS X X

X 34 USGS X X

X 36 USGS X X X

X 35 Wild-Heerbrugg Instru-ment, Inc.

X 66 Wild-Heerbrugg Instru- X Xmenl, Inc.

X 25 Wild-Heerbrugg I nstru- X X X X X X X Xmenl, Inc.

X 30 \Vikl-lIecrbrugg lnstru- Xment, Inc.

X U. S. ~avy X

30 Itek Corp. XXIS The Ohio SLale University X

17 JIJ6I USAF Film I.ibr. X

45-50 X X X

X 30 1964 USAF Film Libr. XXX 25 Kational Fill11 Board X

(Canada)30 1'164 ASP (CBS) X X20 U.S. :\'avy X30 U.S. Army X24 1952 USGS

X

XXXX

X

X

XX

X

X

Other films mentioned include:A film on imagery from Geoscience nivi~ion of Texas InstrumentsVarious Canadian Films from Dept. of Mines & Tech. Services, Surveys & Mapping Branch, Ottawa, Ontario, Canada (Note:

Problems of duty even for loan)Many Army and Air Force film sequences on maps, map reading and associated sciences.

Also of special note is a Pre-Programmed Lecture on Photogrammetry & PI in EDEX by AutometricOregon Stale University is thinking in terms of a taped lecture with instruction only in the laboratory period.

films were produced In the 1950's and thatseveral have become obsolete and should bereplaced. The most popular films were Inlro­ducing Pltologrammetry by \ rild- Heerbruggand an Introduction to PllOlo-fnterprelatiou bythe SGS (AID). The suitability rating showndepends 011 a small sample of people with

yanous backgrounds and objecti\'es and IS

not significant. It would appear that theconscientious instructor should pre\'iew thesefilms and see how they fit into his program,or. an emi nen t board of photogrammetriceducators In vanous disciplines should actas a screening board and classify the films

A Sl'I{\,EY OF TIC\I:\I:'\G .\lDS 293

carefully as to suitability for basic courses,elective courses or special graduatc courses.Perhaps then, thc main value is a concise listof films al'ailable to the teacher of photo­grammetry in all its ramifications. It II'ouldalso seem that good, instructil'e, color footagcshowing operation, manufacture and theoryof a manufactures instrument lI'ould be agood ill\'estmcnl in future sales-if thc film iswell donc, essentially non-commcrcial andkept in good repair and up-to-datc. For thedescriptions of somc films and for the ad­dresses II" here the fi Ims arc a vai lable secAppendix A.

SLIDES A:\D STEREOG[{A~IS

Thc replics to thc inquiry concerningslides and stereograms was marc varied(Table 2). Speci fic sets of slides show that ingeometrical photogrammetry, the slides bymanufactures showing thcir equipmcnt wercmost used. Thcre appears to be a need in someareas to del'elop an integratcd sct for loan orpurchase and the Education committce ofASP could do this by copying sclectcd ~igurcs

from thc Jf(/1//wl of PllOlogrllmmelry andManual of Pliolo-lulerjJrelalion, and soliciting

color slides of equipmcnt from all manu­facturers. The availability of an up-to-dateset of this typc, su pplemen ted by locallyproduccd slides should assist in teaching amodern cou rse in photogra mmetry.

The al'ailablc stercograms, show a rela­til'ely hcal'y use of thc annotated set of some27.1, sterco-pairs sclected by the Cnil'crsity ofIllinois faculty. Thcy arc to bc commcndedon their splendid cffort. It is noted, howel'er,that thcsc are nOlI' strictly black-and-whitcphoto imagcry. The latest additions to thcIllinois set do include IR and Radar imagerybut thc incrcasing importance of color,aerial cktachromc infl-a-red, and other sensorsfrom UV, through multispectral band photog­raphy, to microll'al'e mcans that in a shorttime slidcs, stereograms and samplcs of thesctypc imagc,-y must bc produccd for propcrmodernization of tcaching,

:\IODELS A:\D OTHER DEVICES

The u e of this type tcachi ng aid appcarsto bc almost non cxisten t except for the use ofstereo-projections. The usc of modcls andtcaching dCI·ices is perhaps new to manyinstructors howcI'er, a lI'cll design cd model

TABLE 2. :\SP EDl:C.ITIOX C<))IMITTEI·;-TI<.\I);I);<; .\IIJS Qn,;sTIOX);AII<I'; SL'~nIAI<Y

Set Tille Avail. frolll Jj II' Color Sumba/·;x.

5iuiJability

Cd. FlIlY

a. ."'fides 3S min. unles!:i noted

XX

X

xXX

x

X

XXX

X

XXX

xXX

10

50

12241'>1

100

SO,zs,~)

2530

206

XX

X

X

x

XXXX

Dennis Richter, Geog. Dept.\Vise. State V., \.vhilewater.\Vi::;coll~in 5.1190Wiscon:..;in 53190 Whitewater,Zeiss (Aerotopograph)U of Illinois

elMSWild-lleerbruggItekZeis~ (AcrOlOpOgraph)ITC. DelftL'SFS. Wash. D.C.Attn: :Mr. RinehardtAttn: ~Ir. Rinehardt

b. SiereoRrllms &" Film Slrip'i-Usually HI''''

Dr. Bell. C. E. Dept.Oregon Sr. Univ.Corval1i~. Oregon97331Olin Mintzer. C.E.OSU Columbus. Ohio43210

Intermediate P.1.(with tape)

Photo Interpretation

AMS Tr. Col (9 X9 Viewgraph)Photograllltlletric Instrument:,Photogra1l1111etric InstrumentsPhotog-ram metric Equipmt>nlITC Slide CollectionBasic P.1. (with tape)

Photo Interpretation

STE-UrbanGeologicMilitaryVegetatioll

ST E Zei!:is Instrument::.;ST E IIIinoi, PI Set

(5X7 & 8XIO)STE PI (Edition Technique) Pari,. FranceF.S. Basic PI Workbook USFS. Div. of Timbt::r :Management

(With tape for LaBelle Rapid .\ction Automatic Slidp Magazine & LaBelle 88 projector & matching sound system)STE Ba<ic & Intermediate PI l:SFS. Portland. Oregon l.iO (color) X

(Bob POI,e)

----------

-------- ---

(also slides-with tape ([13~ ip,,)------------------- -

294 PHOTOGRAMMETRlC ENGINEERl NG

TABLE 3. ASP EDUCATION COMMITTEE-TRAINING AIDS QUESTIONNAIRE SUMMARY

Models and Other Devices

1. Plastic" clip board" for estimation of angle of dip2. 3-D Projectors

a. Jackson's-DeHavilland Aircraft Co.,Toronto, Ontario, Canada3t slides

b. Stereo-Vividc. T.D.C.

3. Mossners Parallax Test (USFS)4. 3-D Models

a. See PI-JOTOGliAMMETRIC ENGINEERING Sept 65, Mar 65 (Colwell)b. Navy Photo-interpretation Center, Suitland, Maryland

Contact: V. Vakearen or Page Truesdellc. Plastic Models of Tilt & Relief Displacement

Contact: A. ]. McNair-Cornell University5. Charts on basic mathematics of photos6. Wild B-9 Training Samples

can supplement even the real thing at times.The models mentioned are listed in Table 3.J t is obvious that model deformation asmeasured in an Wild A-7 autograph is helpful,bu t perhaps models of the distorted surfaceswould help the beginning student. Anothertype of model is men tioned by K ul han 4 andthis idea certainly has merit in some teachingsituations. As a recommendation, the sched­uling of a model seminar at some futureASP Meeting, using a panel of experts to showhow models are used in their teaching situa­tions may be warranted.

One interesting hint of information comesfrom Autometric who appear to be interestedin the field of programmed learning. Theproduction of a text with illustrations andcomputer simulation is intriguing. Similarthinking apparently is taking place at Ore­gon State University. They are consideringtaping a similar but less sophisticated ap­proach to be used in their teaching of basicphotogrammetry. This is, then, perhaps aglimpse to the future where models and audio­visual techniques will have a place.

CONCLUSION

Tt is hoped that this small effort will makea contribution to upgrading of teaching of

1 "Terrain Model Aerial Photo" E. F. Kulhan,PHOTOGRAMMETR]C ENGINEERING, Nov. 1965.

Geometrical Photogrammetry and I mage In­terpretations. Some pertinen t curren t com­ments received are shown in Appendix B.These certainly give an idea of the currentthinking in the field. Clearly, an up-to-date,color film showing the use, manufacture andbasic design elements of a product can be use­ful. The production of an up-to-date slide setutilizing figures from the Manuals publishedby ASP supplemented by color slides ofequipment from manufacturers and users willalso assist in a more informal presentationthat is more adaptable to an instructor'schanging needs. Good models can also sup­plement good teaching and a seminar onwhat can be done would be helpful. Finally,new instructional techniques will necessitatea continual modernization and awareness bythose of us in the teaching profession. (Onelogical method of presentation and updatingof available training aids may follow thepractice used by the Institute of TrafficEngineers in their brochure entitled, "Se­lected Audio-Visual Aids for Traffic Engi-neers."S)

After all, we are in the business of workingeffectively with images and a (good) pictureis worth a thousand words.

5 "Audio-Visual Aids for Traffic Engineers,"lTE Committee 2C(63) an Inventory of Audio­Visual Aids. 1725 De Sales Street N.W., Washing­ton, D.C. 1965.

A Sl'RVEY OF TRAINING .\IDS

APPENDIX A

295

AGE:\CY ADDRESSES A;\D FIUl DESCRIPTlO:-lS.

WILD HEERBR GG INSTRUMENTS, INC., 465Smith St. Farmingdale, L.I., N.Y. 11735.\ \"est Coast Represen ta ti ve. (Films markedIV a\'ailable only.) Sun'eyor's Service Co.,2942 Century Place, Costa l\1esa, Calif.

(W) Introducing Photogrammetry. 16 mm.sound film in color-duration 25 minutes.

The film demonstrates the principles ofPhotogrammetry and shows some applicationsto demonstrate the versatili ty of th is modernsurvey tech niq ue. I t is of in teres t both to pro­fessional and laymen audiences.

Technical aspects covered include determina­tion of geodetic points, air survey lenses andtheir design, explanation of the A-8 plotter'sdesign principles using animation, demonstra­tion of relative orientation, determination ofscale and leveling of the model in the plottinginstrument, plotting of a map with the A-8.

Uses of photogrammetry are shown in Aus­tralia, Japan, Paris and other areas around theworld for forestry, geology, cadastre, planningand engineering. .

(W) .!faking Jlaps the E'/jicie1lt Way. 16 mm.sound film, 2 reels, sho\\'ing time 66 minutes.

Fir,t reel: Assembly and adjustment of photo­gram metric instruments (phototheodolites, Ae­rial Cameras, Plotting Instruments) at the \\'ild­Heerbrugg Factory.

Second reel: L'se of Photogrammetric equip­ment as follows:(a) Large-scale mapping for a technical project

flight with the Wild RC-7a Camera in theSwiss Alps and plotting with the A-7 Auto­graph.

(b) Photogrammetric Land Registry Survey::\llarking the boundary corners, graphicplotting and Registering of the boundarycorner coordinates with the A-7 and thetransformation of the instrument coordi­nates.

(c) Small Scale Mapping: Survey flight with theWild RC-Sa Film Camera. Plotting withthe Wild A-8 Stereo-Plotter. Preparing theprinting plates according to the procedure oflayer engraving.

(d) Aerotriangulation in the 'vVild A-7 Auto­graph.

lntrodu.cing Superwide-A ngle Photogram-metry 16 mm. Sound Film in Color, ap­proximately 30 minutes.

The film gives a fine comparison between wideangle and superwide angle photogrammetry. Itexplains how \\'ild Herrbrugg solved the prob­lems of developing a lens with 1200 angle, thenumerous parameters that had to be consideredand shows clearly how greater economy can beachieved without giving a tribute to accuracy.The large coverage, the reduction of time con­suming ground control work, the favorable ba"eto height ratio and the fewer flight strips which

must be flown proves that such a lens was des­tined to have success.

Aids for mapping and interpretation areshown including:

1) Comparison of infrared and panchromaticemulsions under various flight conditions,advantages of color photography.

2) Determination of pass points combiningelectronic distance measuring and theTheodolite.

3) Point transfer with the \\'ild PUG-3.-I) The use of navigation aids during flight.5) Triangulation in the \\'ild A-9 Autograph.6) And a brief introduction of large scale

mapping with superwide angle photogram­metry.

DEPARTME1\T OF THE AIR FORCE. Air ForceFilm Library Center (MAC), 8900 SouthBroadway, St. Louis, Missouri 63125.

/1 merican Society of Photogrammetry 105 ;\!.

Virginia Ave., Falls Church, Virginia22046.

Film Data:

Cameras .,ltaft, Secrets Below. Black & \\'hite,25 to 30 minutes.

This was a CBS lilm prepared for television in1964. It shows the role of photogrammetry inthe Cuban Crisis and depicts photo-interpreta­tion from the layman's viewpoint.

.S. GEOLOGICAL SUR\'EY

For areas listed, add,'ess inquiries to:

Arizona, California, Hawaii, Idaho, Ne\'ada,Oregon, Utah, \\·ashington. Pacific Re­gion Engineer, U.S. Geological Survey,345 Middlefield Road, Menlo Park, Calif.94025.

Alaska, Colorado, M on tana, New Mexico,Montana, Texas, \Vyoming. Rocky Moun­tain Region Engineer, U.S. GeologicalSurvey, Federal Center, Bldg. 25, Dell\'er,Colorado 80225.

Arkansas, Illinois, Iowa, Kansas, Louisiana,Michigan, Minnesota, Mississippi, Mis­souri, Neb"aska, North Dakota, Okla­homa, South Dakota, \\·isconsin. CentralRegion Engineer, U.S. Geological Survey,Box 133, Rolla, Missouri 65401.

Others. Coordinator, Motion Picture Films,.S. Geological Survey Room 2647 Interior

Bldg., \\"ashington, D.C. 20242.

Le'"ueling For Topograpllic .llapping. Color­Sound, 16 mm., duration 20 minutes.

Depicts technical procedures used by theGeological Survey for the third-order levelingrequired as vertical control for topographic map-

296 PHOTOGRAMMETRIC ENGINEERING

Interpretation of Hydrological16 mm., Color, duration 35

ping. Opening with a rudimentary explanationof the principles of leveling ba-.;ed on sea leveldatum, the film shows the equipment and actualfIeld operations of a Geological Survey levelingparty. Prism levels and precise, invarstrip, self­reading rods are used in the surveying operations,not for the purpose of obtaining greater accuracybut primarily for obtaining a speclic accuracyat the least cost.

Transit Transverse for Topographic Jlapping.Color-Sound, 16 mm., duration 25 minutes.

Sho\\·s the equipment and technique..; used bythe Geological Survey, in terrain of moderate re­lief for transit traverse to determine po.;itions ofth ird-order accurac,· for the basic horizon tal con­trol-the frameworl, upon which the topographicmap is constructed.

The film explains the purpose of transitlraverse and shows in detail the equipment used.A mong the operations shown are the measuringand recording of angles, measurement of dis­lances, methods of locating phologrammetriccontrol points and an astronomic observationfor azimuth.

Triangulation for Topographic Jlapping.Color-Sound, 16111111, duration 30 minutes.

·hows the equipment and techniques used bythe Geological Survey, in terrain of considerablerelief, for triangulation to determine positions ofthird-order accuracy for the basic horizontalcontrol-the frame\\:ork upon which the map isconstructed. I t also sho\\·s the measurement ofvertical angles to determine supplemental con­trol elevations, a method commonly used interrain of this character.

Supplemental Control for Topographic J!ap­ping. Color-Sound, 16 mill., duration 25min utes.

Shows equipment and techniques used by theGeological Survey for determining the elevationsof supplemental-control points for photogram­metric mapping of areas with variolls conditionsof terrain and vegetation.

The film shows how aerial photographs areobtained for modern mapping, the office planningand the field operations used in determining ele­vations. Planetable and stadia surveys, triangu­lation methods, and two-base altimetry methodsare discussed.

Preparation of Topographic j\frtnuscripts forReprodnction. Color-Sound, 16 mm., dura­tion 30 minutes.

Describes in delail the preparation of final("opy for reproduction of topographic maps bysmooth drafting procedure". Since the stepsshown are no\\· somewhat outmoded and arebeing replaced by scribing procedures, thosedesiring to view the current processes of finalpreparation of topographic maps should requestthe film "Negative Scribing for i\Jap Reproduc­tion." However, the drafting procedures shownhere are still being used in connection with therevision of some maps produced during the past20 veal'S, and therefore those interested in bothmethods should view bOlh films.

Negative Scribing for JIap Reprodnction.Color-Sound, 16 mm., duration 24 minutes.

Shows in detail the procedures involved inpreparing negatives for map reproduction byhand scribing. heet coating, guide copy prepara­tion, and close-ups, of the various scribing opera­tions and instruments are presented.

Tellurometer. Color-Sound, 16 mm., duration12 minutes.

Shows the equipment used in the Telluromete'­System of microwave distance measurements.Explains how equipment is transported to thestation from \Vh ich the measuremen ts are takenand shows the crew setting up and operating theinstruments.

TTEK CORPORATION. 10 Maguire Road, Lex­ington, Mass. 02173. Washington ContactOffice: 1735 I Street N. W., Washington,D.C.

From Jennies to Satellites.

The film is a production of an Educat ionalTelevision Station (\\"GH S-TV). I t should notbe considered a training aid but an untechnical,general interest production on the personal his­tory of General George Goddard and his experi­ence in Air Force reconnaissance.

Aerial Photo Interpretation Films

Introduction To PllOto Interpretation. 16 mm.,Color, duration 22 minutes.

Provides training in the techniques of photointerpretation for the discovery and evaluationof the natural resources of a country or region.

.lerial PhotoResources.minutes.

Provides training in the techniques of photointerpretation in the discovery and evaluationof the hydrological resources of a country orregion.

Ii erial Photo Interpretation of Forest Resources.16 mm., Color, duration 39 minutes.

Illustrates how the techniques of photo inter­pretation are used to assist in the discovery andevaluation of the forest resources of a zone.

A erial Photo Interpretation of Geological Re­sources. 16mm., Color. duration 34 minutes.

Illustrates how the techniques of photo inter­pretation are used to assist the geologist in thediscovery and evaluation of resources such asminerals, fuels, and constructive materials.

,.ferial Photo Interpretation of Soil Resources.16 mm., Color, duration 36 minutes.

Shows how soil surveys are expedited by theuse of photo interpretation. I t points ou t thatproven techniques in this field combined with alimited amount of field work, make possible a

r\ SURVEY OF TRAINING AIDS 297

general evaluation of the soil resources of a rc­gion quickly and economically.

U.s. GEOLOGICAL SURVEY.-The InformationOffice, Washington, D.C. 20242.

Airborne Jfagnetometer. 16 mm., Black &\,"hite, Sound, duration 24 minutes.

Explains use of the airborne magnetometerwhich allows scientist, in aircraft, to gain infor-

mation on mineral bodies in otherwise inacccs­sible areas.

ABC System. 16 mm., Color. Sound, duration13 minutes.

Shows how the recently developed AirBorneControl Survey System (ABC) used the helicop­ter as an aerial electronic target in surveying andmapping opera tions. Demonstrates basic ele­ments of system including the unique StabilityAugmentation System for precision hovering.

APPENDIX B

Selected Comments from Correspondenls(Out of approximately 60 specific comments received)

"1 would be interested in seeing a summarylist of films, slides, and special structuraldevices that other institutions are using.... "

"Due to curriculum changes resulting in afewer number of electives, we have not offeredour elective course in photogrammetry forseveral years. However, recently there seemsto be a demand for this course so we hope tooffer it again soon. I am looking forward torenewed activity in this area so we would beinterested in the results of your survey."

"'Xe are developing our Engineering Sur­veying course and we hope that we will ha\'esome of the training aids which have beenused in teaching photogrammetry at theUniversity level in the near future. Unfor­tunately, we have no motion pictul-e films,slides or special I nstructional devices at themomen t at our U niversi ty. Therefore. wewill be very pleased to use any training aidsavailable from the Committee in our under­graduate program."

"Vve need a collection so transparencies,with appropriate overlays, for use withoverhead projector, to develop systematicallythe visualization of basic photogrammetricprinciples and carrying on to instrumenta­tion, etc. A measure of animation can thus beobtained without resotring to movies whichare expensive and Jess readily revised, northe order of presentation altered as situationdemands."

"\\'e need air photos, black-and-white aswell as color on 35 mm. slides. Carrousel-typeprojector has made the Ii ttle slide the bestpossible training aid for nearly any class.Film strips are too restrictive on the lecturer.

Good solid models of some sort should beavailable to illustrate. Geometry of single airphoto. overlapping pair, the tilted photo,the earth ellipsoid, orientation of stereo pairetc. Training aids should be used with dis­cretion in University level instruction. Photo­grammetry and Photo I nterpretation bytheir very nature lend themselves to the useof training aids.... "

"I have used very Ii ttle in the way of films,slides. or models in my photogrammetrycourse. Howe\'er, I probably "'ould if theywere readily available and [ believe yourcommittee is undertaking a very worth­while project. I shall be interested in theresu Its.... "

"I believe there is a need of a film or filmstrip which can be used at Junior High orHigh School level for Public Relations. Pos­sibly there should be a consolidation by ASPof slides and film stl-ips available and thenpublicized to all Universities and colleges ato their availability."

"Vve do not use any visual aids of any typein any of our course .... "

"I am able to teach our course in Photo­grammetry which meets six hours per weekfor one quarter without using slides or films.\\-e visit the Highway Department Photosection to observe Kelsh A-7 plotters, and theoperation of a mapping section.... Byactually doing this work the student learnsmore than by viewing a film."

"Preparation of airphoto stereo pairs to beused with 35 mm. stereo slide projector which

298 PHOTOGRAMMETRIC ENGINEERING

uses polarized method (projector availablecommercially) and polarized glasses worn byaudience, such stereo slides would be extremelyval uable for classroom discussion of photointerpretation."

"Vve need more modern testing materialfor examining and training stereo vision. Allmajor instrument companies as well as majorgovernmental and private surveying, photo-

grammetry, and mappi ng agencies shouldprovide the pertinen t University Depart­ments with demonstration material such asfilms, slides, stereograms, etc."

"The University of Illinois Series isexcellent. ... vYe intend to make use of thisseries of Stereograms when we can obtainthem. Other items of teaching equipmenthave had greater priorities."

Discussion of I Down to Earth I

Dear Editor:

Presiden t H ei nz Gruner has presen ted inhis paper, "Down to Earth," PHOTOGRAMMET­RIC ENGINEERING, October 1967, the case forpractical photogrammetry, and quite rightlysays, "Traditionally the surveying profes­sional observes an honored code of ethics andsound practice inimical to exaggerations andspeculations." I am in hearty agreement withhis approach to preserving the integrity of themapping profession and to aiding the photo­grammetrist whose work is routine (in thesense that he provides a standard product tohis customers) in making the most efficientand best use of his skills and equipment.

But I am also in great disagreement withhis tenet that the articles in PHOTOGRAMMET­RIC ENGINEERING are becoming oriented to"very specialized fields remote from earthlyusefulness and remote from the needs of themajority of our members," and that suchorien tation is undesirable. The scien tists andengineers in these "very specialized fields,"are not motivated by a "search for excitementand revelation" but are motivated by a desireto find solutions to the problems of copingwith our environment. Photographic, photo­grammetric, and remote sensing techniquescan aid in these solutions.

Let me cite an example. Aerial photographsare routinely taken under rigid specificationsfor use in standard topographic mapping. Thebasic metric quality of the photographs is wellutilized by the photogrammetrist when heplots the metric and cartographic data on acontrolled map projection. The finished topo­graphic map is his product, and a good one.But the task of the map user has just begunand, because the map contains only a smallpercentage of the information in the originalphotograph, the user needs both the map andthe photograph to accomplish his task. Thus,

the geologist uses the map as a metric base toplot the interpretive data that he extractsfrom the photograph on geologic structure,outcrops of bedrock, extent of alluvial de­posi ts, and so on. The forester may use thesame photograph and the same map to guidea timber cruise. Thus, the photograph has amultitude of uses beyond its originally in­tended photogrammetric use (a fact oftenoverlooked in determining the cost/benefitsof aerial photography).

As important as photogrammetric qualityis, we can not overlook the in terpreti ve as­pects of aerial photography and the need forcon ti nually assessi ng the q uali ty of our en­vironment, a task for which aerial photog­raphy and space photography are admirablysuited.

The resource scientist who is earnestlysearching for better ways to assess the en­vironment has seen that space photography,such as the Gemini photographs, is useful forsuch evaluations, quite apart from its short­comings as metric photography. From both atheoretical and an engineering standpoint, ithas been demonstrated that small-scale met­ric photographs can be obtained from spaceand at a cheaper cost per unit area than aerialphotography. In addition, useful photog­raphy and imagery suitable for interpretivepurposes, but lacking in complete geometricfidelity, can also be obtained from space.

I t is well to beware of exaggerations in theclaims for space sensing but it is the job of thescientist to speculate and say, "vYhat if ... ?"If it had not been for such speculation in the1800's, practical photogrammetry would notbe the indispensable tool it is today. Today'sspeculation, fenced in by scientific methodand harnessed by the hard facts of engineer­ing, may lead to a new era of practical photouse-both in photogrammetry and in photo(and image) interpretation.