Cartography: Contemporary vs. Manual Surveying
Exercise
Manual
Manual cartographical efforts included hand tools to survey targeted areas, early compasses, and mathematics where contemporary efforts include less hand tools for surveying and more implementing technology, such as handheld GPS devices and computers that calculate for the users. This project draws comparisons between manual map-making and surveying methods to contemporary map-making and surveying methods within Memory Grove Park (~coordinates 40.77657, -111.885139), a public green space located within Salt Lake City, Utah. The study took place on a Monday, the date October 11th, 2021 with cloudy weather at 40℉ (~4.44℃).
The manual map-making was conducted first for approximately one hour from 11:06 A.M. to 12:04 P.M. The region’s midsection, slightly north of the bench area, was the target. Measurements were taken with toe-to-heel steps; the shoe size was a women’s 7, which is approximately 9.25 inches, and when converted to feet with the equation ((x inches / 12.00 inches) = (9.25 inches / 12.00 inches)) = 0.77 feet—the amount of steps taken were converted to feet multiplying by 0.77.
I decided on a rectangular path around the study area and an arbitrary starting point southwest of the City Creek River, moving north 448 steps (~344.96 feet), then moving east 253 steps (~194.81 feet). Then moving south, making sure to cross the outermost bend of the footpath then west back to the starting point. The rest of the footpaths were measured, then the lengths of the river edges, noting the bench, grate, and monument on the map. The scale was determined as a one-inch scale equalling 65 steps (~50.05 feet), and I’m no math genius so unfortunately the margin of error was around 15 feet.
Contemporary
The modern map-making was done with a Trimble GPS, an old ~$100 Juno 3B with meter accuracy depending on the user’s expertise, to take note of the coordinates mostly around the footpaths, river edges, and bridges for a total of twelve points, which took less than thirty minutes after booting up the device from 12:45 P.M. to 01:11 P.M.
Points—Names
A—southwest corner
B—center of south bridge
C—river southwest side
D—bell
E—river west middle
F—river northwest side
G—center of north bridge
H—northwest corner
I—northeast corner
J—river northeast side
K—river southeast side
L—southeast corner
The coordinates were taken and input through a post-processing application, GPS Pathfinder, to create and export .csv data points from an .ssf to a .cor file, one uncorrected and the other corrected with the Differential Correction tool. These points were then transferred over to ArcGIS to map the points, and compared to the manual hand-drawn map with the XY Point Data tool.
Map notes: Forgot to label points, apologies.
Thoughts
The manual mapping method was proportionate, although there’s some distortion due to my inaccuracies making the map and the appalling 15 feet margin of error. The modern mapping methods had margins of error no more than 3 meters (less than 10 feet), so they were significantly more accurate compared to my manual map. Comparing the corrected and uncorrected points, the latter was shifted approximately 2 meters westward compared to the corrected points, which were more aligned with the pathways and river edges.
However, the major differences between the two methods were the efficiency and time of the efforts. Where manual mapping took around 2 hours for the entire process, modern mapping was more or less around 10 to 20 minutes taking points and no more than 40 to 60 minutes to post-process the data in GPS Pathfinder and create maps in ArcGIS Pro. Distance, scale, and proportion were automatically calculated, requiring little to no user changes—digital map making methods are generally reliable representations compared to manual mapping methods, which are prone to human error, though don’t think I did too horribly my first time.
Cartography made great strides and technological improvements, providing many different methods to map-making—not only did technology improve the diversity and variety of ways to survey, it also significantly improved accuracy, accessibility, efficiency, effort, time, and reliability in mapping. Technology has allowed information and other important data to be stored in virtual files for safekeeping instead of curating hand-made maps, files that could be re-used for a variety of projects and re-used in mapping as well as post-processing applications—there’s little room for human error and I’m glad I live in the era of technological dominance because I wouldn’t want to manually survey in 40℉ weather ever again, so this made me greatly respect pre-GPS map makers.