RESEARCH COMMITTEE REPORT 867

Research Activities in the Field of Plotting Theory and Instruments

by S. A. Veres

AERO SERVICE CORPORATION being undertaken to establish the pres­ ACTIVITIES of the Aero Service Corporation ent limitations and the prospects for rt has been devoted to the development and further improvement. These are weighed testing of the Laser-Airborne Profile Recorder against the analytical developments and a new Airborne Magnetometer. The with particular emphasis on the future Laser-Airborne Profile is one of the most economical aspects of the instrumenta­ promising instruments for the photogram­ tion. These studies may resul t in com­ metrist and is capable of achieving accuracy pletely new concepts leading to a sound better than a foot. The Airborne Magnetom­ economical solution. eter has contributed to the exploration needs 3. Special Plotter Applications. New ap- of petroleum and mineral industries since plications of photogrammetry to 1947. The new magnetometers based on the a. Dental research electro-optical properties of cesium vapor, b. Electron-microscopy rubidium vapor and helium, are capable of c. Underwater micro relief studies measuring the magnitude of the total mag­ are being studied. netic field vector to a resolution of one hun­ 4. Projected Scale Micrometer. Two types of dredths of a gamma compared to the resolu­ optical/mechanical measuring attach­ tion of one gamma of previous instruments. ments have been developed for Bausch & BAUSCH & LOMB INCORPORATED Lomb's Stereo Zoom Microscope and Zoom 70 when used as a Stereo Zoom Bausch & Lomb has been conducting the Microscope. The instruments permit the following projects in the field of plotting making of measurements on photo­ theory and instrumentation: graphs to one one-hundred thousandths 1. Projection Plotter Lens Investigations. of a foot (.00001 foot), equivalent to The conventional Hypergon lens has approximately 3 microns. The instru­ been the standard lens for direct pro­ ments attach to the microscope pod. jection plotters for several decades. It The measurements are independent of has served well for angular field coverage the viewing magnification, unaffected up to 90°. Beyond that its limitations by any distortion in the viewing optics become aggravating. These are lack of and do not require the placing of any­ resolution and strong vignetting at mar­ thing in contact with object or film ginal regions of the projected field. being viewed. Angular coverage of 120° has de­ 5. Optical/Electronic Absolute Measuring manded a more complex lens system as System. Several investigations for the already developed at B & L, which ex­ Bausch & Lomb DIG long-travel digital cels by almost doubling the resolution of linear measuring system which utilizes the Hypergon lens and completely elimi­ glass scales for measuring to micron nating the internal vignetting which is precision. At present it is being installed detrimental to the marginal illumina­ on a Mono-Comparator and is proposed tion of the projected field. for use on a coordinatograph type in­ A series of lens systems is presently strument for digitizing the stereo tem­ being developed also in the 90° field plet from projection plotters to permit which can replace the Hypergon. The adjustment on a computer rather than new lenses are of the quadruplet cate­ a templet lay-down. gory and will cover the range of small, 6. Variscale Stereo Point Marking Instru­ medium and large scale mapping pro­ ment. The variscale Stereo Point Mark­ jectors. ing Instrument is currently under de­ 2. Plotter Concept Studies. A general review velopment at Bausch & Lomb for GIM­ of the direct projection system, the opto­ RADA. It is intended for use in produc­ mechanical and the purely mechanical tion mapping to provide for the identi­ system of mapping instrumentation is fication and precision marking of con- 868 PHOTOGRAMMETRIC ENGINEERING

jugate image points on aerial photog­ er reticle size and located it for a given raphy. The VSPM is designed to point of interest. handle a variety of format sizes (up to Film Holddown-Diapositive . plates 9X 18 inches) on film ordiapositives, and and film chips from 70 mm. to 19" X 20' scale differences up to 16:l. in size are held flat by means of a vacu­ Coarse conjugates of marked points, um system. Vacuum pressure is variable as well as other input data may be re­ for purposes of alignment and positive corded by means of an IBM 526 card holding during operation. punch, which is interconnected. Photo Display-Positive prints of the The VSPM and its related compo­ films on the photo stages are displayed nents are designed for "clean room" on a photodisplay panel. A tracking operation. light spot is projected onto the prints to Optical System-a binocular viewing indicate the actual location of the optical system permits stereoscopic viewing at system axis as the films are scanned. continuously variable magnification This permits the operator to readily from 2 X to 32 X. Each half of the position any desired area of the film in optical train may be zoomed indepen­ the field of view of the optical system. dently for differential scale matching. 7. Zoom 95 Stereoscope. One of B & L de­ Derotation prisms provide 360 degree velopments which was originally in­ image rotation in each optical path. tended primarily as an interpretation Other features such as interpupillary tool has found wide application as the distance adjustment, individual eye­ viewing system used with hand point piece focusing, X- Y phoria adjustment, markers. The following characteristics parallax removal by means of a floating have been found to be especially useful mark, and optical switching are in­ in point marking operations: cluded. Zoom Magnification-4 to 1 ratio Scanning System-X and Y scan Working Distance -51; inches motions are controlled by a joystick for Optical Image a continuous range of film speed from Rotation -360 degrees each side 25 mm.jsec. for slowing to 1 micron/sec. Object Separation -3 to 71; inches accom- for precise micro alignment. modated. Both photo stages may be driven in­ BELL AERO SYSTEMS COMPANY dividually or simultaneously. The illu­ mination level on each photo stage is in­ Bell Aerosystems Co. has developed an dependently variable. integrated mapping system for mapping areas Measuring System-Coarse coordi­ Where ground control is not available, by the nate positions (least count 0.1 mm.) for employment of an inertial navigator. Terrain each photograph are displayed visually clearance laser measurements are obtained to on nixie readout tubes, located on the develop control in photogrammetric param­ instrument panel, and may be recorded eters, which are compared with inertial permanently on command by the opera­ measurements to provide a bound for system­ tor to the card punch. atic photogrammetric error effects. I t is shown The readout system can be switched that all ground control can be eliminated ex­ to the short range micro measurements cept for a single photopoint coordinate triad mode to permit measurements of 1 to serve as the datum for the mapping block. micron increments which are also dis­ U. S. ARMY ENGINEER, GIMRADA played visually. This system provides assistance in parallax removal and serves GIMRADA's-activities in plotting as a check for point marking accuracy. theory and instruments in process as follows: Point Marking-A unique sy~tem a. Universal Automatic Map Compilation molds marks into the film emulsion. Equipment (UNA MACE). A Universal Several marking dies are provided which automatic mapping system fabricated range from a 200 micron circle to a 40 by the Bunker-Ramo Corporation, micron dot. A flagging mark is also in­ Canoga Park, California, is undergoing cluded. Mark intensities may be varied tests. by the operator to provide the optimum b. Automatic Photomapper. A contract has marks for particular emulsions, however, been awarded the Bunker-Ramo Cor­ the marking system is fully automatic, poration for fabrication of a rugged ver­ once the operator has selected the prop- sion of the Universal Mapping System RESEARCH COMMITTEE REPORT 869

which will be suitable for mapping generate directly on-line. Plots up to 100 operations in direct support of the Field points per minute. Army. 3120 Dataplotter. Output-point or line c. Reconnaissance Plotter. An analytical plot. Input-cards or punched tape. Will plotter which will accept various types operate directly on-line. Plots up to 100 of non-mapping, reconnaissance-type points or 150 lines per minute. photography is under development at 3130 Dataplotter. 3110 or 3120 on-line with the Bendix Corporation, Southfield. a computer or a data processing unit. Michigan. This activity is co-sponsored 3440 Dataplotter. Output-line, point or by Air Force and GIMRADA. Delivery symbol plots. Input-magnetic tape, is expected in early 1966. This plotter punched tape, cards and manual keyboard. will utilize an analog-type computer. Points can be plotted at a rate of 350 d. Ultrawide Angle Plotter. An anaglyphic points-per-minute. Lines may be drawn at projection plotter designed and built a speed of 4,500 points-per-minute. Allows under contract by Belfort Instrument for use of 16 or 48-character symbol printer. Company, Baltimore, Maryland, IS As many as 180 distinct symbols-per­ undergoing tests. minute may be printed. e. High Altitude Plotter. A projection-type plotter for 12-inch focal length photog­ GALILEO CORPORATION OF AMERICA raphy fabricated by Aero Service Cor­ Galileo Corp. has introduced Stereocarto­ poration, Philadelphia, Pennsylvania, graph Model V as a more sophisticated ver­ under contract, will accept 9 X9, 9 X 15, sion of the popular Model IV. The instrument or 9 X 18-inch frame photography. is based upon the mechanical projection £. AP/2. Tests are in progress to deter­ principle arranged in "horizontal" position mine the capabilities of the AP/2 Analyt­ which reduces the distance between the two ical Stereoplotter. A series of tests will cameras. The focal length range is from 85 be conducted to determine the plotter's mm. to 215 mm., so the instrument is suited suitability for military mapping from a for evaluation of super-wide-angle photo­ wide range of types and sizes of photog­ graphs. There are four correcting devices for raphy. Mapping procedures using this each camera. Two are for correction of "sys­ instrument are also being developed. tematic" instrumental errors and the other two for correlation of "accidental" errors of CARL ZEISS/ZEISS AEROTOPOGRAPH photographic images. The possibility of base­ As the results of extensive research done by in and base-out enables the instrument to be the company several new products have been used for aerial triangulation. The Stereocarto­ marketed. These are: the TS4 pocket stereo­ graph Model V effectively can be used as a scope, the L 2 viewing desk and the N 2 mirror stereo comparator. As a further achievement stereoscope. In addition the company is oc­ the introduction of Stereosimplex lI/c should cupied with optical, mechanical and electrical be mentioned, which is the modification of problems. Thus they have completed the Stereosimplex lIlb designed for adoption of drop-line device for the Orthoprojector, pro­ super-wide-angle photographs. The instru­ duced the rotary lamelle shutter with a ment is based on the mechanical projection 1/3,000 sec. exposure time for aerial cameras principle. The instrument also is capable of and tested a color attachment for SEG V solving small graphic or numerical aerial tri­ Rectifier. In addition the PSK stereo com­ angulation and for evaluation of oblique and parator and the automatic coordinatograph terrestrial photographs. have been modified to a certain extent. GENERAL ANILINE & FILM CORPORATION ELECTRONIC ASSOCIATES, INC. Extensive research has been conducted by In every-day photogrammetric research the corporation in the field of Microdensitom­ and routine production more and more re­ etry. As a result of this several microdensi­ quirement is placed upon a graphical repre­ tometers have been made available to the sentation of digital information and data. The photogrammetrist who is interested in the EAI developed a dataplotter system which is evaluation of samples of photographic ma­ capable of fulfilling this requirement. This terials where the recorded image is of impor­ system consists of: tance. The G.A.F. precision photogrammetric 3110 Dataplotter. Output-point plot only. instruments include microdensitometers, mi­ Input-cards or punched tape. Will also croline evaluator and micro-image scanners. 870 PHOTOGRAMMETRIC ENGINEERING

GOODYEAR AEROSPACE CORPORATlO)l in elevation so as to provide a true ortho­ graphic radar presentation. Arizona Division has conducted a research program in All Weather Mapping sponsored Akron Division has done several studies in by the U. S. Army Corps of Engineers support of mapping and reconnaissance data GIMRADA. The objectives of this program reduction. The most important from a point are: of view of the plotting theory and instru­ In addition to supplying radar mapping mentations are: systems directed toward satisfying tactical mapping needs, the Army is also required to The Stereo Viewer. This is an optical device that is a product of a company-funded de­ provide a capability for producing topo­ velopment effort. It projects a three-dimen­ graphic maps under peacetime conditions in sional image from the overlapping portions geographical areas which are continually ob­ of 70 mm. serial-frame photography. The scured by clouds. To fulfill this need, the U. S. operator sees a three-dimensional image by Army Engineer GIMRADA conducted in­ looking at a semi-specular screen without vestigations which led to the following pro­ wearing any polarized or colored lenses. A posed system concept. unique optical system, employing a Fresnel The data acquisition portion of the All lens, produces a spatial mode. that allows Weather Mapping (AWM) System would be the photointerpreter to maintain an ex­ contained in an RC-135 type aircraft. The tended eye relief. ControIs include scale­ major components for this airborne subsystem factor compensation, brightness, and dis­ would consist of a terrain profile recorder placement of one projected image with re­ (TPR), a position system (SHIRAN), and a spect to the other in translation and rota­ high-resolution coherent Side-Looking Radar (SLR). Mapping information of an area tion. would be obtained by flying the aircraft along Psychophysical Viewer. The psychophysical various flight paths with all three sensors in viewer was conceived, designed, built. and operation. From these flights there would be installed aboard the ]KC 63596 aircraft recorded the area imagery in slant range from within three months under contract AF33­ the radar, the aircraft's positions from the (657)-9476. It was used by the 665A project SHIRAN ranges, and the terrain profiles office for in-flight psychophysical tests. The beneath the aircraft flight paths from the viewer contains three independent optical TPR. channels that project imagery from 5-inch I t is the purpose of the current investiga­ strip films onto three 11 X 11-inch rear-pro­ tion to analyze the system parameters to jection screens with coordinated, servo­ determine optimum data acquisition tech­ controlled cross hairs. The three strip films niques and flight configurations, and to es­ can be driven at variable speeds in syn­ tablish design requirements for ground-based chronism, or individually, in either direc­ data processing equipment. This effort can be tion. The cross hairs are driven in unison by separated into two main areas of investiga­ velocity servos in response to a manually­ tion: manipulated tracking control. Intensity 1. Computer Studies-provide and demon­ can be controlled and polarity of the cross strate the validity of a computer pro­ hairs can be reversed (black vs. white). gram for the interpolation of contours Live film can be displayed directly from an from an array of spot elevations and in-flight correlator and processor. determine the most suitable spot array configuration. Also, recommend a com­ High-resolution Electronic Display System. mercially available plotter along with all Goodyear Aerospace is currently designing necessary modifications to provide a and fabricating an 1100 line electronic dis­ plotting unit capable of processing this play system that utilizes a high resolution data so as to provide a contour sheet for P-16 flying-spot scanner with a half mil a 1/250,000 scale topographic map. spot size. The Monitor utilizes a 14-inch 2. Orthographic Rectifier-establish and CRT with P-4 phosphor and a spot size of design requirements for an orthographic 3-mils. rectifier which will utilize the elvation data from the computer program to con­ High-resolution Radar Viewer. Under Con­ vert the slant range radar image to tract AF33(657)-9461 for a high resolution ground range and compensate for rela­ radar data-processing and display investi­ tive displacements caused by variations gation for the RS-70, Goodyear Aerospace RESEARCH COMMITTEE REPORT 871

has studied and fabricated a breadboard of the study of soil, minerals, geography, a rear-projection display system including techniques of map making and transfer of two screens with coordinated cross hairs. map information. The objective was to Both displays are projected from a single identify the factors in radar photogram­ image. In the small-scale factor display, the metry that are pertinent in the mapping of cross hairs move over the scene, while in the information from radar returns. Results in­ large scale display the scene moves under cl uded development of procedures and the cross hairs. techniques adaptable to an all-weather mapping system that uses high-resolution Change Detection Studies and Development. radar as a terrain sensor. Under Contract DA-44-009-ENG-4462, Modification No.2. for the U. S. Army HRB-SINGER CORPORATION Engineering Cent'er, Fort Belvoir, Virginia, For over a decade HRB-Singer has con­ engineering studies were conducted on ducted research and development programs principles and methods to automatically applicable to airborne infrared thermal map­ detect changes in two photographs. Two ping systems and other electronic informa­ techniques of change detection were eval­ tion projects. Based on these experiences the uated. Company made available for military and Goodyear Aerospace is currently under commercial use, several remote sensing sys­ government contract to design and fabri­ tems. Among others the Airborne Radiom­ cate a change detector that will quickly and eter, Model AR1, the Reconofax VI infrared accurately detect and display comparative thermal-mapping system. Furthermore sev­ differences that exist in any two photo­ eral studies conducted by the Company in graphs covering the same scene. This elec­ connection with the application of these sys­ tro-optical instrument automatically reg­ tems in the field of oceanography, infrared isters the two photographs being compared, imagery for mapping drainage patterns and and within seconds presents changes as for fire detection. prominent bright areas on a background display of the two superimposed photo­ KELSH INSTRUMENT COMPANY, INC. graphs. Theoretical and experimental investiga­ The Kelsh Instrument Co. has recently tions are being conducted on long-term developed a dodging projection type printer change detection under a classified contract for making diapositives. The printing time 40 AF33(657)11379, with ASD. to 90 seconds depending upon plate speed and negative density. Scale can be varied to pro­ Synthesis of Radar Imagery. Basic research, duce uniform scale diapositives taken with development of techniques, and the fabrica­ cameras of 150 to 156 mm. £.1. The printer tion of hardware for synthesis of radar also can be used to print negatives taken with images has been conducted to expand the cameras of other focal lengths, to produce a 1 operational capability of the ATRAN to 1 diapositive. The company has also com­ guidance system in the TM-76A Mace pleted development of a full-size inverse tele­ Missile. This included extensive studies of photo type projection lens which can be used terrain classification, radar target charac­ in the latest model K-IOO plotters. teristics, and simulation equipment. The KERN INSTRUMENTS, INC. coordinated efforts of cartographic, photo­ graphic, electronic, and optical scientists The Kern PG 2 Stereo Plotting instrument culminated in the activation and operation is well-known to the photogrammetrist of this of the Air Force's Map Synthesis Section at country. The several unique features em­ Orlando Air Force Base, Florida. This facil­ bodied in this new plotter have been reported ity is an integrated system for the genera­ to the photogrammetric society; the latest of tion, on a production basis, or synthetic these was given by F. Goudswaard, on the radar reference films for the TM-76A Mace "Compensation for Earth Curvature Influ­ Missile System. ence in the Kern PG 2" reported to Tenth International Congress of Photogrammetry, Mapping Study. Goodyear Aerospace con­ 1964. However, the Company is presently en­ ducted a program to extract mapping de­ gaged in a research for the further develop­ tails from high-resolution radar photo­ ment of PG 2. Unfortunately, details on this graphs under Contract DA-44-009-ENG­ program are not available at the time of this 4462 with GIMRADA. This work included report (December, 1965). 872 PHOTOGRAMMETRIC ENGINEERING

MARK HURD AERIAL SURVEYS, INC. extraction of altitude data and simultaneous The technicians of Mark Hurd's Santa preparation of an orthographic projection Barbara Office are perfecting a "Miniprinter" photograph as a step in the production of which will enable a photogrammetrist to print topographic maps was proved feasible with the aerial negatives at a 50 per cent reduction. development of the Automatic Map Compila­ This is planned to save time and space in the tion System. A second generation system for indexing phase of photogrammetric practice use in a production environment, the Univer­ and the filing of proof prints. sal Automatic Map Compilation System equipments (UNAMACE) have passed initial SYRACUSE UNIVERSITY acceptance tests. These systems use hybrid Syracuse University has completed a study analog and digital techniques to locate corre­ of Photogrammetric Measurements of Dy­ sponding imagery on stereo pairs of aerial namic Displacements. The study was spon­ photographs to determine attitudes and ex­ sored by National Science Foundation and pose a new photograph on which the image conducted by B. A. Wasil, D. C. Merchant elements appear in correct map relationship and J. J. Del Vecchio. An analog method has with all photographic distortion removed. been developed during the investigation in These instruments besides being fast and ac­ order to reconstruct the bundle of imaging curate compilation instruments, have a 4­ rays from two or more camera stations. The micron Lm.S. capability as comparators, and reconstruction is made to generate a three di­ theassociated computer has been programmed mensional optical model of the vibrating plate to perform resection calculations. effectively fixed in some selected phase of the oscillatory cycle. The Porro-Koppe principle \¥ILD HEERBRUGG INSTRUMENTS, INC. has been employed. Viewing of the model is An experiment with super-wide-angle pho­ accomplished through stereo observation of tographs using Wild A9 Plotter has been com­ the processed negatives directly by means of pleted as reported by Prof. Hugo Kasper, special stereoscope located above the projec­ Federal Institute of Technology, Zurich. The tion camera. The three dimensional model is experiment utilized photographs taken of plotted by introduction of a reference mark 2,900, 4,400 and 7,200 feet altitudes over a into optical model consisting of a point source test area that had previously been surveyed of light and located under the projection for cadastral purposes. The standard error cameras. The instrument is able to provide for the A9 compilation with the lowest alti­ the evaluation of close-up photographs. tude found to be ± 23 cm. horizontally and ± 18 cm. vertically. With this investigation it THE BUNKER-RAMO CORPORATION has been pointed out that the users of the A9 The Corporation has been engaged in the and B9 group of instruments in developing past with research on automatic map compila­ countries are able to produce engineering tion from stereo aerial photograph. Automatic plans or cadastral maps at the scale of 1 :2,000.

Recent Research and Development Activities in Aerotriangulation by H. F. Soehngen

NUMBER of large photogrammetric organi­ U. S. GEOLOGICAL SURVEY A zations have continued research and The current investigation of the Topo­ development programs in aerotriangulation. graphic Division encompasses two general The major emphasis is on the development of approaches to the aerotriangulation problem, analytical aerotriangulation techniques utiliz­ the analytical and semianalytical. Both sys­ ing medium and large size electronic com­ tems utilize electronic data processing proce­ puters. dures in conjunction with digital readout A report in detail of the activities of the equipment. agencies which answered a questionnaire will The analytical system derives both vertical indicate the scope of the large effort being and horizontal positions of ground points by a exerted to automate this branch of photo­ purely mathematical approach of an iterative, grammetry. simultaneous, least squares adjustment based