Initial Publication Date: April 24, 2018

Assessment of Module Goals

Instructions

There is no single summative assessment for this module. This is because kinematic and static GNSS require different equipment and different interpretative tools. Instead, we offer a suite of questions that can added into the summative exercise of different units. Alternatively, these questions can be asked as part of a final exam.

Although there are three fundamental questions that all students should be able to answer at the end of this module, instructors may select additional questions from the list below. This selection can include a minimum of one task-based assessment, one question justifying the given technique, and one question that asks the student to consider the societal benefit of answering a given question. Instructors should feel free to design questions that ask details about the specific field site they used. Specifically, open discussions with students on the societal value of answering a research question about that location and why the technique chosen was the most appropriate for the job.

Grading rubrics are provided as an outline for knowledge-based assessments, but instructors are encouraged to heavily weight student progress and active participation in field-based activities. Remember that the key goal for these modules is to teach students the skill of designing and executing a survey with the given technique.

Module Goals

While assessing student skills, remember the overall module goals.

Students will be able to:

  1. Design and conduct static and/or kinematic GPS/GNSS surveys to address a geologic research question.
  2. Apply the findings of GPS/GNSS surveys to issues important to society
  3. Justify why different high-precision positioning techniques are appropriate in different situations.

Assessment Questions

Kinematic GPS Questions (Units 2, 2.1, and 2.2)

Core Questions

  • Evaluate how well your selected survey design was able to answer your question of interest. Given unlimited resources, how could you modify this survey design to improve the results?
  • For a given geologic application, justify why it would be worth the extra effort to use kinematic GNSS rather than a simpler mapping-grade tool or the more complex static tool. Answer this question by explicitly discussing uncertainties in the methods and the precision needed for your application.
  • What are the societal benefits of this research? Write three sentences in plain English that would communicate this benefit in some public medium like a newspaper.

Additional Questions

  • You are executing a kinematic GNSS survey. Something goes wrong (e.g., your precision begins to drop off, your precision erratically switches from low to high, etc.). Walk through the potential causes of this issue and propose a solution. (Instructor selects the particular issue.)
  • You are tracking the down-slope movement of monumented boulders on a talus slope using repeat kinematic GPS surveys. In subsequent years, you find that the boulders have all roughly moved the same amount (~1.3 m) but in a direction that seems unrealistic, e.g. toward the side-slope. What are a few potential explanations for this issue and how would you resolve it?
  • I want to measure the course of a winding, bedrock river (think Grand Canyon). Would it be better to use the post-processed kinematic or real-time kinematic method and why?
  • You want to quantify topographic change at an active fault scarp by creating two successive topographic surfaces before and after an event. Why is it important that the two surveys are executed consistently? What could happen if points are collected in different locations during the two surveys?
  • An active landslide is flowing down-slope. You have two options: (1) you could create monuments and track those points through time, or (2) you could generate a topographic surface using a broad array of nonmonumented points spread across the surface. If you wanted to calculate volumetric change of the landslide, which technique is best and why? If you wanted to calculate the surface velocity of the slide, which technique is best and why? For each answer, explain also why the alternate technique would fail.
  • Consider: you are surveying the slumping of a hill-slope within a suburban area that is encroaching on a public building. How would you design a kinematic survey to quantify the rate of deformation of the slide? How would the measurements benefit land managers who need to mitigate the threat of this and future threats?
  • Consider: you are surveying the migration of a river within a floodplain that is open for development. Land managers would like to know how to best utilize all the land but need to understand the how the river will interact with the terrain. How would land managers benefit from a topographic survey of the floodplain and channel? Justify why a kinematic system would or would not be ideal for this project.
  • Given a large work group of 5–6 people and a limited amount of equipment (1 base station and 2 RTK rovers), make up a survey scenario and explain how you would allocate labor and resources to complete a job efficiently.

Static GPS Questions (Unit 3)

Core Questions

  • Evaluate how well your selected survey design was able to answer your question of interest. Given unlimited resources, how could you modify this survey design to improve the results?
  • For a given geologic application, justify why it would be worth the time and effort to use static GNSS rather than a simpler mapping-grade tool or a kinematic GNSS survey. Answer this question by explicitly discussing uncertainties in the methods and the precision needed for your application.
  • What are the societal benefits of this research? Write three sentences in plain English that would communicate this benefit in some public medium like a newspaper.

Additional Questions

  • You are executing a static GNSS survey. Something goes wrong (e.g. technical issues with power or connections on the station, poor precision recorded, no satellites listed on receiver, etc.). Walk through the potential causes of this issue and propose a solution. (Instructor selects the particular issue; this may be best done hands-on.)
  • You are measuring the movement of monumented objects on a landslide using campaign static GNSS surveys. In subsequent years, you find that the monuments have all roughly moved the same amount (~1.3 m) but in a direction that seems unrealistic, e.g. up-slope. What are a few potential explanations for this issue and how would you resolve it?
  • You want to measure the differential movement of a basin as it is deformed by an active feature, e.g. fault, water withdrawal, etc. What would be an appropriate spatial and temporal sampling design for a static campaign survey and why?
  • You want to quantify topographic change at an active fault scarp by measuring two successive leveling lines before and after an event. Why is it important that the two surveys are executed consistently? What could happen if points are collected with different methods or techniques during the two surveys?
  • An active landslide is flowing down-slope. You have two options: (1) you could create monuments and track those points through time, or (2) you could generate a topographic surface using a broad array of nonmonumented points spread across the surface. If you wanted to calculate how the landslide deforms with response to another variable in time, which technique is best and why? If you wanted to calculate the surface velocity of the slide, which technique is best and why? For each answer, also explain why the alternate technique would fail.
  • Consider: you are tasked with understanding the effect of groundwater on the subsidence of a river basin that is extensively utilized for agricultural purposes. How might a static survey of the area help to answer this question. Would a campaign or continuous survey be the most appropriate option and why?
  • Consider: you are working with a seismologist to mitigate the hazards of a local volcano on a town. How would you design a static survey so that it could capture the inflation of the volcano as an indicator of volcanic activity? How could this be a beneficial addition or complement to seismic sensors or remote-sensing techniques such as InSAR? What style of survey would be most effective and why?

Method Comparison Assessments

  • What are the costs and benefits of kinematic versus static survey styles?
  • What are the pros and cons of using real-time (RTK) versus post-process (PPK) kinematic surveys?
  • How can you adapt the proponents of a given system—Kinematic (high density/low precision) or Static (low density/high precision)—to solve a problem that benefits society.

Example Rubric


Example Summative Assessment Elements and Accompanying Rubric (Microsoft Word 2007 (.docx) 214kB Apr14 18)

This is an example rubric containing a small selection of questions that are currently used within module assignments to assess summative learning from students. Not all questions used appear here. Review individual assignments for more ideas.