Geospatial Field Methods

Final Project Overview and Expectations
Geospatial Field Methods
Spring 2020
Your final project will consist of two parts, for the first part you will compare your
hand drawn map to GPS points collected over the same area. For the second part,
you will use the photos and GPS points collected by your group in the field to
produce two separate Digital Elevation Models (DEMs) and orthomosaics of your
selected study area. Recall, you were testing a hypothesis about some element that
changed between flights that would results in different DEM resolution or quality.
You will analyze the difference between the DEMs by comparing the reports
produced by Agisoft Metashape (Professional Version), and by mapping the
difference in surface elevations between the two DEMs using GIS. Your final project
should include:
Part 1 (1-2 pages)
1. A picture or scan of your hand drawn map
2. A map of the GPS points overlaid on satellite imagery
3. Discussion of how they compare
Part 2 (5 pages)
1. 5 Maps (2 Orthomosaics, 2 Digital Elevation Models/Hillshades, 1 Difference
map)
2. Discussion of how they compare
The data processing and analysis can be carried out as a group or individually, but
the written reports must be written and turned in individually, in your own words.
Any plagiarism or copying will results in a zero on the final project.
Data Acquisition
Data was collected over spring break using Juno GPS units and DJI quadcopter UAVs
to collect overlapping photos.
Data Processing
Post process your GPS points using the instructions provided by Hannah.
For part 1, you can import those points into Google Earth, ArcPro, or other GIS
software and visualize them with satellite imagery as the base map. You can choose
either the cabin area, or the ‘Top of the World Area’. Then assess the difference
between your hand drawn map and map including the GPS points in terms of
distance and scale, and discuss challenges associated with mapping without
modern tools.
For part 2, you will be importing the GPS points that are associated with your
ground controls points in your flight area as a CSV into Agisoft metashape.
Process your photos in Agisoft Metashape (Professional Demo version)
 For both flights, produce a separate DEM and orthomosaic
(https://www.agisoft.com/index.php?id=34)
 For both flights produce reports (File->Export->Generate Report)
Assess the difference between the two DEMs
 The report will contain useful statistics/metrics that can be used in the
comparison, for example, pixel size or number of pictures used to produce the
surface model
 Export DEM’s and orthophomosaic (I suggest Geotiff file format)
 Create a difference DEM in ArcPro or other GIS software. This can be done by
opening both DEMs, converting them to the same resolution (resample tool),
and then using raster math to carry out a ‘minus’ operation. This will map the
differences between the two DEMs (i.e. the difference map will show where
elevation is higher/lower in one DEM relative to the other)
 Feel free to come up with other ways to compare the surface elevations of the
two DEMs
 Write up your findings in a report consisting of an introduction, methods,
results, and conclusion. The group may do the analysis together, but each
person must turn in their own report, written in their own words.
Maps
 Using GIS software, produce your maps and include all map elements (i.e.
Title, North Arrow, Scale Bar, Legend)
 Your DEM’s can be visualized either as surface elevations, or as a hillshade
Final Reports
The report should be ~7 pages of text with 11-12 point font text with single or 1.5
line spacing. You must include a minimum of seven figures. Two from part 1: your
hand drawn map, a map of GPS points over the same area. Five from part 2: an
orthomosaic and DEM produced from the first and second flight, and a difference
DEM. DEM’s can be visualized in map form using surface elevations or by producing
a hillshade. You can include more figures as you see fit. Figures are not part of the
report length and should be included after your references rather than embedded
within the text. The report will be turned in electronically.
Reports are a standard part of field work/field methods. Treat this like you are
turning it in to a client or boss. Use proper paragraph structure and full sentences.
When writing any report, consider the following mantra for organizing
your paper:
INTRODUCTION. METHODS/TOOLS. RESULTS. DISCUSSION/LESSONS
LEARNED. CONCLUSION.