In this lab, you will build on what you did in the previous lab in order to do an adjustment of the small trilateration network you designed there. You will need to reduce the observations to the mapping plane, in turn requiring you to code the related functions. Like other labs in the series, this one about bringing spatial networks to life for yourself and understanding them as deeply as possible as you build out your own coding library.
The practical applications of this one are being able to:
- Reduce slope distances to the ellipsoid;
- Reduce those ellipsoidal distances to the grid; and
- Carry out an adjustment of the observations you determined were required last time.
You’re also going to:
- Add the related new functionality in order to build on your C++ network library; and
- Work as a team to develop and submit a final implementation.
1. Watch the introduction
2. Consider the following context
This time I want you to imagine that you sent your field crew out to measure the distances you specified in our earlier lab, and that they’ve provided you with the field-corrected and calibrated slope distances you told them were needed in order to meet the specifications.
Now it’s your job to do the adjustment.
But first you’re going to need to reduce the slope distances to the mapping plane!
And, because I want you to build out your library, that means you’re going to have to write functions that allow such reductions, as well as the last few steps required to carry out a least squares adjustment.
Deadlines + assessment + individual vs. team work
If you’re taking this from me as part of a university class then:
- The due dates for this work are outlined on our activity schedule which you can access with the tabs at the bottom right side of any page on this site.
- A detailed marking rubric will be handed out via D2L and discussed in class. Don’t hesitate to reach out if you have any questions at all.
- You’re asked to use the lab report report template when submitting your lab.
This lab requires individual work and then requires you to work as a team with others. As discussed in the following, you are asked to:
- Develop a Google Sheet for the reduction in Part 1
- Code your own solutions in C++ to round out your own library (in Part 1, Part 2, and the first half of Part 3); and
- Come together as a team (in Part 3) to land on one C++ implementation that you’re going to submit to represent the work of your team, and do some analysis of the situation.
We find it helps the learning a lot when each person has done the individual work in this lab before coming together on a solution, which is why it’s structured that way and why you each need to hand in your individual solutions as an appendix to the final report. Each person’s understanding gets stronger this way. They do better on the related tests. And the overall results are stronger.
3. Check out these related modules
The following modules might be helpful:
- Introduction to using spreadsheets as a sandbox tool for spatial applications
- Introduction to browser-based coding as a sandbox tool for spatial applications
- Measures of precision and accuracy of coordinates in spatial networks
- Introduction to the reduction of observations for geospatial networks
4. Get started!
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