RAMP: a computer system for mapping regional areas Bradley B. Nickey PACIFIC SOUTHWEST Forest and Range Experiment Station FOREST SERVICE lJ S DEPARTMENT OF AGRICULTURE P.O. BOX 245, BERKELEY, CALIFORNIA 94701 USDA FOREST SERVICE GENERAL TECHNICAL REPORT PSW-12 11975 CONTENTS Page Introduction ........................................... 1 Individual Fire Reports ................................... 1 RAMP ................................................ 2 Digitization Requirements ................................. 2 Accuracy .............................................. 2 Computer Software ...................................... 2 Computer Operations .................................... 4 Converting Coordinates ................................ 4 Aligning Coordinates .................................. 4 Mapping Sections ..................................... 6 Application ............................................ 8 Literature Cited ......................................... 9 Nickey, Bradley B. 1975. RAMP: a computer system for mapping regional areas. USDA Forest Serv. Gen. Tech. Rep. PSW-12, 9 p., illus. Pacific Southwest Forest and Range Exp. Stn., Berkeley, Calif. Until 1972, the U.S. Forest Service's Individual Fire Reports recorded locations by the section-township-range system..These earlier fire reports, therefore, lacked congruent locations. RAMP (Regional Area Mapping Pro- cedure) was designed to make the reports more useful for quantitative analysis. This computer-based technique converts locations expressed in section-township-range notations into latitude-longitude coordinates. Two subsystems make up RAMP. The technique can be applied to other types of land-management problems. Oxford: 439:582:U681.4 Retrieval Terms: fire case histories; burn pattern; mapping systems; coor- dinates; locations; computer programs; RAMP; Regional Area Mapping Procedure. Tho Anthn~ BRADLEY B. NICKEY is an operations research analyst with the Station's fire management systems research unit, headquartered at the Forest Fire Laboratory, Riverside, Calif. He was graduated from San Diego State College (B.S. degree in general engineering, 1961; M.S. degree in business administration, 1966). Before joining the Forest Service in 1967, he worked as an industrial engineer at Norton Air Force Base, in California. Muchinformation useful for land-use planning re- Oregon, illustrates the complexity of the problem mains untapped by computerized retrieval systems @g. 1). because of the cost of correcting inadequate land 10- Sections are nominally 1 mile square; townships cators. A typical example of this problem is found in are 6 miles by 6 miles and contain 36 sections. The the U. S. Forest Service's Individual Fire Report half townships (T.25 1/2S.)?however, contain six sec- (Form 5 100-29). In 1972, the form was revised to tions, and one of them is much smaller than the record fire locations in degrees and minutes of lati- others (see section 31, fig. I). Irregularities such as tude and longitude. But until then, the section, town- these preclude the use of the existing locator for com- ship, and range in which the fire started were re- puter analysis. corded. This location is appropriate for statistical Spatial analysis of the Individual Fire Reports ar- tabulations, but is not suitable for quantitative ana- chives requires a change to a congruent locator, such lysis. Therefore, much of the information in these as degrees latitude and longitude. Highly accurate earlier reports is not available to the fire manager and computer-based mapping systems that use legal land planner. descriptors, least-square error techniques, and other To tap this reservoir of historical information, a sophisticated methods are available, but are costly computer-based technique called the Regional Area (Swann and others 1970). For many jobs a high de- Mapping Procedure (RAMP) was developed. RAMP is gree of locator accuracy is not critical. designed to provide longitude and latitude values of section corners and midpoints from digitized map 10- cations of townships. This report describes RAMP, its characteristics, digitization requirements, and computer software, and suggests how the system could be used in solving other types of land management problems. Instructions on how to prepare input for the com- puter system are found in the Procedural Guide for the RAMP Quantization and Coding Process. The Guide is available upon request to: Director, Pacific Southwest Forest and Range Experiment Station, P. 0. Box 245, Berkeley, California 94701, Attention: Computer Services Librarian. INDIVIDUAL FIRE REPORTS The individual Fire Reports are a primary source of wildfire information used in fire prevention, fuel treatment, and fire planning. Generally, the planning techniques currently used require manual processing of this information. But computer-produced tabu- lations and summary reports are available by using keypunched copies of the form. Analyzing the spatial information in the Individual Fire Reports by advanced quantitative techniques would require a computer. However, such work has been hampered by the format of the report-partic- Figure 1-The township configuration found on the Deschutes National Forest, Oregon, includes half ularly its location of the fire by the use of the sec- townships (6 sections) as well as full ones (36 sec- tion-township-range system. The township and tions). Some of the sections may be much smaller than section pattern of the Deschutes National Forest, in others. RAMP The time required for digitizing is a function of the number of townships within a forest, the amount RAMP (Regional Area Mapping Procedure) accepts of key information required, and the number of non- the errors inherent in a map, and converts the section- rectangular sections it contains. For example, on the corner projections into degrees latitude and longi- Clearwater National Forest, in Idaho, it was necessary tude. Briefly, the system involves digitizing the loca- to digitize 463 records to cover 3646 sections. Many tions of the corners of a few sections in each town- of these records were required to process an extraor- ship. Variations from nominal size are identified and dinarily large number of nonrectangular sections. distributed among the sections, by procedures similar This work took about 3-112 hours. On the other .to the General Land Office survey rules for handling hand, only 116 records were needed to cover 54 1 1 errors. Finally, the locations of all remaining sections sections in the Tonto National Forest in Arizona. In and the centroid of each section are computed. With this case, about 2 hours were needed to digitize the this system, digitizing one township can result in as maps. many as 35 section locations being calculated auto- The average number of sections calculated for each matically by the computer. Locations by lati- digitized record for seven forests is 15.4 (table I). tudellongitude and section/range/township are then However, considerable differences from the average cross-referenced. existed for different forests. RAMP consists of two interrelated subsystems: one converts section corner locations on a map to a digital ACCURACY recording of an x-y coordinate in a form compatible for computer processing; the other provides instruc- Analysis of the magnitude and direction of calcu- tions that take advantage of township surveying prin- lated locations for 53 points, taken from nine dif- ciples and section numbering configurations to mini- ferent forest maps, showed no systematic errors over mize the amount of digitizing. the range of latitude and longitude examined. The computed standard error for latitude was 252 feet DIGITIZATION REQUIREMENTS and 437 feet for longitude (table 2). The scale of all of the maps digitized was % inch Many different characteristics exist on commer- to 1 mile. The smallest line digitized on these maps cially available digitizers. Some of the more critical was clearly legible at a viewing distance of 5 feet. This differences are (a) fixed versus variable length digital would indicate that the lines were at least 0.03 inch records-a record is the unit of data to be transmitted wide (Robinson and Sale 1969). A line of this width to the computer, (b) nu~nberof x-y coordinate points is equivalent to a distance of 316 feet on the maps that can be entered on a record, (c) availability or analyzed. One of the more accurate computer-based limitations or both on keying information into a rec- systems accepts calculated points which have an error ord, and (d) coordinate alignment procedures. Each of less than 200 feet at the latitude/longitude inter- difference affects the digitizing and coding proce- sections (Swann and others 1970). It would appear dures. In turn, each procedure influences the com- from this comparison that the errors associated with puter program used to process the digitized infor- RAMP are reasonable-especially for maps of the mation. scale used in the study. In RAMP, nine different digitized records are used. They provide the essential information for (a) devel- COMPUTER SOFTWARE opment of scale coefficients for conversion of x-y corner locations to degrees latitude and longitude, (b) Many commercially available digitizers have built- alignment of the x axis of the digitizer coordinate in functions to insure the alignment of the coordinate system with the longitude axis of the map, (c) identi- system with a map system that covers a small geo- fication of the latitude and longitude at the origin of graphic