APPLICATION OF SHAPE-PRESERVING SPLINE INTERPOLATION TO INTERACTIVE EDITING OF PHOTOGRAMMETRIC DATA
Original Publication Date: 1978-Dec-31
Included in the Prior Art Database: 2005-Sep-15
Software Patent Institute
L. E. Deimel, Jr.: AUTHOR [+6]
Let the points ((xl,Yt)) be decreasing (y,>y,+,, and let (SI )j sAttsfy Sl_<01 1<1
THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.
APPLICATION OF SHAPE-PRESERVING SPLINE INTERPOLATION TO INTERACTIVE EDITING OF PHOTOGRAMMETRIC DATA*
L. E. Deimel, Jr. D. F. McAllister C. L. Doss, II J. A. Roulier** R. J. Fornaro
*This work supported in part by Rome Air Development Center under contract no. F30602-75-C- 0118 and in part by NSF grant no. MCS76-0403.
**Department of Mathematics, North Caroli'nA State University
Let the points ((xl,Yt)) be decreasing (y,>y,+,, and let (SI )j sAttsfy Sl_<1
The Integrated Photogrammetric Instrument Network (IPIN) is being:denigned And developed by the Defense Mapping Agency Aerospace Center in St. Louie., No. to meet database demands for terrain elevation information. IPIM is a network of cam-puters and instrumentation dedicated to digitizing and editing photo-source terrain data . Editing procedures are required because of digitizing errors inherent in the data-collection process. Some of these errors are random; others are systematic and predictable.
The techniques of one of the editing procedures being developed may find application elsewhere. The procedure of interest here involves smoothing raw data that have been collected by the operator of an analytical atereoplotter. When digitizing geomorphic features from aerial stereaphatogrnphs, the double-line drain (DLD) presents Special problems. The digitizing of a DLD (a relatively broad river or stream) requires specifying, triples (x,y,z) (lati- tude, longitude, elevation) at points spaced along the length of each shoreline. The drain boundaries thus collected.usaally have Acceptable latitude and longitude values. The elevation values, however, require st-onthing.
11. THE DOUBLE-LINE DRAIN EDIT
The double-line drain edit Involves modtfi-cation of raw boundary data to meet two require- ulentn: the data must not -.how the river flowIng uphlll, and each point nit a boundary must be At oe vamp. elevation as a corresponding location $#opposite" that point on the other shoreline. Although the latitude-longitude co-ordtnatos of drain boundaries can be obtained with acceptable accuracy from the analytical stereoplotters, elevation values so obtained are less reliable. For this reason, the boundaries muet be edited to ansure that the requirements are met.
North Carolina State University Page 1 Dec 31, 1978
APPLICATION OF SHAPE-PRESERVING SPLINE INTERPOLATION TO INTERACTIVE EDITING OF PHOTOGRAMMETRIC
Data editing for IPIN is done by operators at edit stations using CRT graphics terminals. A witti- computer, sharad by two edit stations, pro- vi4es most of the computationa ' I power needed for data editing. Unedited data are transferred to this edit mini from other units of the network and edited data are sent back. Although other computers are available for particularly time- consuming editing computation, it is desirable to do as much computing at the edit mini as posgible....