# Data Filtering and Noise Reduction

#### Summary

This lab utilizes the computer program, Excel. In this exercise students will generate synthetic data sets based on a simplified model of daily high temperatures in Boone, NC and apply several filtering techniques to the data. A key to this lab is that the students must use Excel in an efficient manner; otherwise, this exercise may take a long time to complete. Thus, the synthetic data sets are intentionally large in size. The overarching purpose of this lab is two-fold: 1) Perform some quantitative data processing and determine the effectiveness of several types of simple mathematical noise filters, and 2) Make a professional interpretation and recommendation based on quantitative results.

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## Context

#### Audience

This is the second lab activity in a sophomore level undergraduate geophysics course.

#### Skills and concepts that students must have mastered

Students must have basic algebra skills (translating and stretching a function). Students must also be given a decent introduction into how to efficiently process data in Microsoft Excel.

#### How the activity is situated in the course

This activity is used during our section on data processing. Teaching about stacking and digital filtering is not effective unless students are made to perform this type of filtering and see the results for themselves.

## Goals

#### Content/concepts goals for this activity

The goal is for students to perform some basic mathematical noise filters and determine which is most effective at removing random noise. This also gives students practice at processing a realistically large data set using Microsoft Excel.

#### Higher order thinking skills goals for this activity

The students must be able to correctly program the relevant equations into Excel and then describe the importance of the results.

## Description and Teaching Materials

Assignment (Acrobat (PDF) 397kB May4 12)
Answer Key (Excel Format) (Excel 2007 (.xlsx) 1.8MB May4 12)

## Teaching Notes and Tips

The instructor must be relatively clever with Excel and willing to give students a short crash course on Excel shortcuts. Students always need a surprising amount of help with Excel basics, so be prepared for this. This is a great first assignment because once the students get through this assignment, you do not need to show them how to make plots of data anymore.

## Assessment

The final written lab report is graded.