CAVE SURVEYING PROGRAMS A List of Features Compiled by the Texas Speleological Survey General-- 1. Name & version of program: Walls v1.0 2. Written by: David McKenzie, Austin, TX (davidmck@bga.com) 3. Year completed: 1994-95 (should be available in Spring, 1995) 4. Price: Free or nominal cost 5 Available from: To be determined 6. Thumbnail description: Walls is a Windows based program for cave survey data management still in the early stages of development. Its design is motivated in large part by the desire for better data screening capabilities for ongoing projects in Texas and Mexico. 7. System requirements & capabilities, including peripherals: Any system capable of running Windows applications. Notebook operation is feasible, but a video capability of 1024x786x256 and a laser printer is nice to have. 8. Can use math coprocessor: Yes 9. Printer/plotter drivers available: Depends on Windows support. 10. Advantages of program: A graphical interface, much of which should already be familiar to users of Windows applications. Project components are kept in a tree-like hierarchy that can be rearranged by dragging branches around with the mouse. Any subset of the data can be processed, which can produce multiple network fragments. Blunders are quickly localized with a detection algorithm based on how much an individual traverse's deletion would reduce the sum of squares in a linear statistical model. Suspect measurements are highlighted (in dialog listboxes and screen plots) along with their "best corrections". These are the corrections that would in effect be applied if the corresponding vector had been given zero weight in the adjustment. Walls employs a numerical algorithm (matrix modification) that makes the efficient computing of such statistics possible. 11. Possible disadvantages of program: Restricted to Intel-based computers running some version of Windows. The program will not be generally available until I complete a few features considered necessary for serious use (rather than just demonstration). As this is being written (Feb 12. 1995) work has been temporarily suspended due to lack of sufficient free time. Data Management-- 12. Data management style (one file, hierarchical, etc.): The program is similar in some ways to the graphical programming environments offered by Microsoft and Borland. Like program source code, raw survey data are maintained in multiple ASCII text files which can be organized into a tree-like project. Any branch or leaf node can then be "compiled", producing a network that can be examined in various ways. There is normally a separate file for each surveying team and/or date. (The style of maintaining a single large file is possible but not nearly as convenient.) 13. Data entry screen can be customized: A built-in Windows MDI-style text editor with enhancements to support easy entry of columnar (tab-delimited) data and auto sequencing/prefixing of names is provided. Proportional fonts can be selected. 14. Station name auto prefixing/suffixing: Auto prefixing and auto sequencing is provided, but not auto suffixing. 15. Input/output units: Meters, feet, degrees, mills. Order and type of columns may be specified for data entry. The allowed measurement formats are currently rather limited but sufficient to represent the field book data I've seen. 16. File import/export: Walls will import an SEF file created by SMAPS v5.2. The SMAPS hierarchical directory structure is represented by the Walls project tree. Also supported is the conversion of Bob Thrun's CMAP data format to the Walls format. When the HTO survey data exchange standard (currently being developed under the leadership of Doug Dotson) takes hold, an export/import capability will be provided. 17. Database/inventory features: When the program compiles a selected project branch or survey, a corresponding set of work files is created. The files are XBase compatible except for the presence of binary numeric fields. A separate program is available for examining them. Data Processing-- 18. Maximum number of vectors: The current 16-bit version of the program limits the number of vectors in a processable component to about 16000 (the only practical limitation likely to be encountered). 19. Type of loop closing: Linear least-squares. For the sake of processing efficiency the program uses by default a simple statistical model where errors in vector components are assumed uncorrelated with variances proportional to vector length. This approach has proved effective enough for data screening purposes. To obtain the required statistics the numerical algorithm computes directly a partial inverse of the normal equation coefficient matrix. The Win32 version of Walls may offer (as an option) a realistic model for variance that doesn't ignore correlations. (Its practical advantages will be insignificant for most projects, but at least we're not limited so much by the hardware.) 20. Processing speed (slow, medium, fast): Fast enough. With the current version, complete processing of the Systema Purification data (11000+ vectors and 900+ adjusted traverses) takes 15-20 seconds on a 486DX-66. This will likely change. 21. Statistical error analysis: Effective for detecting blunders and data recording errors, even with the simplified model for error variance. This can easily be tested by introducing fake blunders. The Walls user should be able to immediately locate such a blunder unless the perturbation is too small to constitute a departure from the model. Also, the suggested correction should reveal the amount that a measurement was perturbed. Other statistics are provided that gauge the overall quality of projects, of independent loop systems, and of traverses within loop systems. A so called confidence region for a relative location can be determined from the statistics. Graphics-- 22. On-screen graphics: The map panel of a "tabbed dialog" displays a plan view of the selected network component. Colors are used to differentiate between 1) vectors outside of loop systems, 2) vectors in non-selected systems, 3) vectors in the selected system, and 4) vectors in the selected traverse. Zooming and panning of the map panel and spawning of additional plot frames is provided via a "tracker rectangle" controlled by the mouse. A few other graphics and printing options (profiles, labeling, coloring and marking by vector and station attributes, grid lines, etc.) are being developed and will be available in the program's first release. 23. On-screen scale & north arrow: Yes 24. Map rotation: Yes 25. Oblique/profile views: Profile options planned 26. Perspective view: No 27. Attributes/colors: Yes (see above) 28. Coordinates/GIS features: A table of station coordinates can be generated. 29. Cross-sections: No 30. Clipping: Yes 31. Positioning of title, scale on plot: Planned 32. Quadrangle plotting: Planned