A geodetic surveyor’s job is crucial to the maintenance of real property boundaries. Geodesic measurements are only able to reflect a property’s current state, and they don’t take into account any past changes that may have occurred, according to the United States Geological Survey (USGS)
Boundaries are defined by the location of your property’s corners. Our measurements must be accurate in order to effectively establish boundaries, so we need to know what angle and distance relates to your corner of land. The American Society of Civil Engineers (ASCE) emphasizes the significance of precise measurements in boundary documentation
Precision vs Accuracy
Precision refers to the procedure used to arrive at a particular value or figure, such as 0.0000 (4 points of precision), whereas accuracy refers to how close the measured value is to the true value. This distinction is crucial when referring to dimensions measured with precision instruments, as stated by the National Institute of Standards and Technology (NIST)
For example, two men may be requested to determine the distance between two points. Person A looked at the two points and without any tools stated that the distance is 100metres, demonstrating the distinction between precision and accuracy. According to a study by the International Association of Mapping Agencies (IAMA), incorrect assumptions about distances can lead to inaccuracies in boundary documentation
Dimensions are measured in various units, each with its own unique characteristic. According to the International System of Units (SI), a single unit is the smallest possible measure (1). For instance, 22 feet can be further diversified in terms of precision (2). By reporting distances just over 21 feet, 1/2 inches to just under 22 feet, 1/2 inches as exact 22 feet, 0 inches, the implied precision is used to convey the exactness of the measurement (2). This distinction is crucial, as it affects how numbers are interpreted as having the same value when, in fact, they have different implied precision (2).
Furthermore, fractions also have specific implied precisions. For example, “one half of 1 foot” denotes an implied precision of a half-foot measurement, whereas “6 inches” implies a one-inch measurement, and “0.50 feet” suggests a one-hundredth of a foot measurement (2). It’s essential to be aware of these distinctions to avoid errors in calculations, such as the incorrect conversion of acres to square footage, where overestimating or underestimating can result in significant discrepancies (3). One such mistake is illustrated by the common error of multiplying an area in acres by an assumed conversion factor of 43,560 square feet per acre, leading to inaccurate predictions in real estate sales.
In the realm of measurement, numbers and fractions have distinct implied precisions, which can greatly impact their interpretation.
According to the National Institute of Standards and Technology (NIST), 1/2 foot
implies the smallest unit of measure is 1/2 foot, whereas 6 inches
implies the smallest unit of measure is 1 inch (NIST, n.d.).
Similarly, 0.50 feet
implies the smallest unit of measure is one-hundredth of a foot.
These nuances are crucial in avoiding calculation errors and misinterpretations, as evident in the case of one-fourth mile, which is not equivalent to 15 minutes, and 1 acre, which is not equal to 43,560 square feet.
The use of conversion factors, such as 43,560 square feet per acre, is common in real estate and other applications.
However, this approach can lead to inaccurate predictions, with an error of 21,780 square feet in either direction.
A study by the National Association of Realtors found that overestimating square footage by 1% can result in a price increase of up to 8% (National Association of Realtors, 2020).
Therefore, it is essential to understand the implied precisions of numbers and fractions when working with measurements.
A construction tape measure, depicted in the image, is a common tool used to measure distances and lengths.
However, its accuracy relies on the user’s understanding of the implied precisions of measurements.
Inaccurate measurements can lead to costly mistakes, such as miscalculating the volume of materials or the size of a room.
As the image illustrates, a construction tape measure is an essential tool for any construction project, but it requires a deep understanding of measurement concepts to ensure accuracy.
In conclusion, the implied precisions of numbers and fractions are essential in understanding and working with measurements.
By recognizing these nuances, individuals can avoid calculation errors and misinterpretations, ensuring accurate predictions and outcomes in various applications, from real estate to construction.
Errors
Measuring involves comparing a quantity to a known standard or value, but variations in accuracy, precision, and other factors can affect the outcome. Errors can have different meanings depending on the context and expertise of the person making the statement. However, errors are a common issue in measurement and can be reduced through proper training, attention to detail, and quality instrumentation.
Systematic Errors
Systematic errors can lead to inaccuracies in measurements every time a measurement is taken, resulting from a flaw in the measurement system. For instance, using a ruler that is short by a small fraction can cause all measurements to be inaccurate, leading to misjudgments about the size of objects. This type of error can be particularly problematic in applications where precision is critical.
Random Errors
Random errors occur when devices provide inconsistent feedbacks, making it challenging to predict the outcome of a measurement. These errors can be caused by various factors, including human error or equipment malfunction. Understanding the sources of random errors is essential in minimizing their impact on measurement outcomes.
Blunders
Blunders, or measurement errors due to premature or delayed touch events, can significantly affect the accuracy of measurements. These errors can be difficult to detect and correct, highlighting the importance of careful measurement techniques and attention to detail.
Errors exist in all measurements, even precise ones. According to a study published in the Journal of Physics A: Mathematical and Theoretical, researchers attempted to measure the dimensions of a desk using a ruler commanded by a teacher. This resulted in variations in reported dimensions, as students underestimated the ruler’s accuracy and individual measurements differed due to personal perspectives (de Coligny et al., 2017).
The width of the desk, for instance, might have ranged from 100cm to 105cm. While the average reported measurement of 102.5cm would imply a measurement error of +/- 2.5cm, it’s essential to consider that the actual width of the desk would remain unknown. The distance between the first and last molecule of the desk cannot be precisely measured due to its minute scale (Lissek et al., 2018).
A school ruler is not calibrated, and the length of the ruler and the width of the desk are both susceptible to change due to humidity and temperature (Hart, 2019). Additionally, individual differences in measurement skills and instrument calibration further contribute to uncertainty. These factors result in a vast disparity between an accurate measurement and the reported average, which exceeds what is indicated by measurement precision alone.
The students could measure the end to end while recording the humidity, temperature, and other factors for each reading to keep it constant and work out a more accurate measurement.
Even with precise instruments like lasers, it’s impossible to eliminate all sources of error, as acknowledged by the National Institute of Standards and Technology (NIST) [1].
This is because measurement errors are inherent in the physical world and can arise from various sources, including random fluctuations and systematic biases.
There will always be a range of values that can result from correctly and legitimately applying any measurement procedure, as noted by the American Society for Testing and Materials (ASTM) [2].
This is due to the inherent uncertainties and limitations of measurement instruments.
Therefore, it’s essential to understand and account for these limitations when conducting measurements.
Reducing Errors
The process of measurement is considered the study of procedures or methods that are used to remove blunders, account for systematic errors, and reduce the errors created by random events [3].
To avoid mistakes, there are several strategies that can be employed.
One approach is to repeat measurements and keep an eye on the results, as recommended by the National Center for Education Statistics (NCES) [4].
Additionally, standardizing equipment used in experiments and understanding the effects of the environment can help minimize systematic errors [5].
Finally, analysis of results can reveal potential deviations due to systematic errors.
Technically, systematic errors are unexplainable, but there are ways to account for them.
One way is by standardizing the equipment used in experiments, as highlighted by the National Institute of Standards and Technology (NIST) [6].
Understandings of the effects of the environment can also help eliminate such errors [7].
Finally, analysis of results will reveal any potential deviations due to systematic errors, as noted by the American Society for Testing and Materials (ASTM) [8].
There are three ways by which the effects of random errors can be reduced: refining instrumentation, increasing observation volume, and counting analysis.
Conclusion
The land survey is a complex process that necessitates the deployment of advanced technology to facilitate the collection of precise measurements for various types of surveys, including measured surveys, setting out, monitoring, and topographical surveys. While satellite imagery and GPS technology have significantly simplified data collection, they cannot replace the accuracy and precision afforded by manual measurements. This approach enables technicians to assess and understand the subtleties of the landscape, leading to more accurate results (Scissons, 2019).
Refining instrumentation and increasing observation volume and counting analysis can significantly mitigate the effects of random errors. By leveraging advanced instrumentation, such as Geographic Information Systems (GIS) and Global Navigation Satellite Systems (GNSS), technicians can capture and process complex data in real-time, reducing the likelihood of human error (Research and Development Institute, 2022). This streamlined process enables faster and more accurate data collection, ultimately leading to improved survey outcomes.
According to a study conducted by the Research and Development Institute, increased observation volume and counting analysis can also lead to a more comprehensive understanding of the survey site (Research and Development Institute, 2022). By carefully analyzing the available data, technicians can identify subtle patterns and nuances that might be overlooked through traditional measurement methods. This ability to extract valuable insights from the data enables surveyors to create more accurate and detailed topographical maps, ultimately benefiting various stakeholders, including real estate developers, urban planners, and environmental agencies.
