Lab 7: An introduction to survey 123

Introduction:

The goal of this lab was to learn how to create a survey using Survey123 for ArcGIS to collect field survey data. This was done via an online ESRI tutorial. In this tutorial a survey was created for a homeowners association (HOA) with 9 safety checks to determine a communities preparedness in the event of a disaster.

Methods: 

The first step of the tutorial involved creating a survey. On the Survey123 website, a template was filled in with the following information.

Name: HOA emergency preparedness survey

Tag: HOA,emergency prepardness

Summary: This survey is being conducted by the HalloOA to help assess the community's emergency preparedness in the event of a disaster, such as an earthquake.

Figure 1
Template for creating a new survey

After creating the survey, the design tab is opened. This tab contains several options for editing the survey. These include add, edit, appearance and settings. The main functioned used to create the survey is the add function which allows the user to insert a variety of question types into the survey layout.

Figure 2
Types of questions that can be added to a survey

The following question types were included in this survey

Singleline text: Allows for a single line response

Single Choice: One choice can be selected from a list

Dropdown: An answer can be selected from a drop down menu

Date: Allows for answers to be entered in date format

Number: Answers can be intergers or a range of numbers

GeoPoint: Users can place a point on an interactive map

Hints may also be added to guide participants in their responses. Also, rules may be added to make questions appear depending on how previous questions were answered. (If a question is answered YES, the second question appears)

29 total questions were included in the survey. Under the collaborate tab the survey was shared with members of my organization (UWEC Geography and Anthropology) 

Figure 3
Sharing survey under the Collaborate tab

The next step was to complete the survey to gather data. This was done a total of 8 times ( 5 times on web browser and three times on the mobile app). The mobile app allows for users to complete surveys on their smart phone in the field.  All eight responses were provided by myself, however in a real world situation multiple individuals would provide responses. 

In Survey 123 data can be analyzed as a group or individually. Many different charts and statistics related to the survey results can be examined here. 

Figure 4
Example of graph under the analysis tab

The final step involved sharing the data with others. This involved creating a map and a web application. When creating the map, certain data was censored so personal information would not be shared. 

Results: 

The final product was a web application that allows users to examine the survey results on a map. Information about each response appears in a pop-up window when the response is clicked on. This makes it very easy to examine specific data related to each individual survey.

Figure 5
Web Application showing locations of surveys

 

Figure 6
Pop up window showing results for one survey

Conclusion

Survey 123 is a powerful application that allows users to collect survey information for a variety of uses. After obtaining my undergraduate degree I aspire to continue my education and pursue a career in Urban Planning, a field in which survey 123 could potentially be used. For example, a survey could be created asking citizens what type of businesses they would like to see in their neighborhoods and their results could put into consideration when developing an empty plot of land. Overall, this tutorial covered the basics of what is a very useful application for a wide variety of data collection purposes. 

Bad Elf GPS

Intro:

The purpose of this assignment was to use the IOS app Bad Elf GPS pro and a Bad Elf GPS receiver, accurate up to 2.5 meters, to track a route that was taken around campus. This route was then converted into a GPX and KLM dataset and uploaded into ArcMap to be mapped. The Bad Elf GPS unit is able to connect to an Iphone via bluetooth and take advantage of the phones superior computing power. This is important, because for a GPS unit to have similar capabilities it would take years to develop, whereas by connecting to existing technology the developers can instead focus on applications for the GPS rather than the GPS unit itself. 

On the topic of applications, the Bad Elf company has created numerous applications for their GPS software, ranging from a wide variety of uses. A few examples are noted below

Pix4d Capture- This app is meant to serve as a companion to Pix4d photogrammetry software. Using the app, drone data can be accessed with an Iphone or Ipad. Additional features include a drone flight checklist as well as a wide variety of image processing.

Air Navigation Pro  - This app allows pilots to plan and track flights using real-time gps information. It provides access to a large database of way-points and flight information. If elevation data is added, flights paths and terrain may be viewed in 3d

Cachly- This app is used for the recreational activity geocaching. This involves participants using a gps follow coordinates in order to locate a small item or "geocache" The app shows an interactive map of geocaches around the world as well as an activity log showing when others located the cache.

Methods:

For this assignment the class was divided into groups; one group was the "hiders" and the other were the "locators". The group in charging of hiding was given an Eureka Marco Polo brand tracking receiver that resembled a small USB drive. The unit is intended to be attached to a pets collar so they can be located if they become lost. The other group used the handheld tracking unit to locate the transmitter and used the Bad Elf app/ GPS unit to log the path they took during the search.

Processing UAS Imagery

Objective and Background

The objective of this exercise is to process imagery using Pix4D, a premier software for generating point clouds. This lab builds off of the previous lab which covered the basics of Pix4D. For that exercise the data was already processed, however this lab will focus on how to process this data. This includes calibrating ground control points, creating an image mosaic and exporting the scene as a shapefile to be mapped in ArcMap. The processed data was obtained from a UAS flight at South Middle School in Eau Claire, Wisconsin by Dr. Joseph Hupy of the University of Wisconsin Eau Claire.

Figure 1
Aerial View of Study Area as seen on Google Maps

Methods:

The Pix4d software is relatively easy to use, however a few parameters must be set before the data may be processed. The first step is to create a new project. This can be done on the opening menu screen. 

Figure 2
Pix 4D opening Menu

 After a project was started, a series of images provided by Dr. Hupy were uploaded. A very important step here was to change the camera settings to linear rolling shutter, which is the particular way that the UAS captured this data. Some processing options that can be selected include the ability to generate shapefiles which can than be imported into ArcMap for mapping. For this exercise the option to create a 3D map was selected. The next step was to import ground control points, or known coordinates in the area of study, to improve the accuracy of our final product. The last step is to uncheck the options for point cloud/mesh and DSM/Orthomosaic on the bottom processing bar. The initial processing can then begin. 

Following the initial processing, a quality check report is generated. This shows any potential errors that could affect additional processing. The error in this quality report was corrected in the following step. During this step, the Raycloud editor was opened and the GCPs were calibrated to match with their actual locations, marked by pink squares in the study area. Three calibrations were done for each GCP

Figure 3
Matching GCP in the software (small blue circle under green x) with real world location (pink/black square)

After the GCPs are calculated, the re-optimize option in the processing bar must be used to adjust the images for the corrected GCPs. The second two processing boxes were checked (the first is unchecked to save time) and after some time the processing finished. The final product was then imported into ArcMap to create a final map.

Results

Figure 4
Orthomosaic Map created from processed UAS Data.

Figure 5
DSM map created with processed UAS data

For this exercise two maps were created. The first of these was a map of the Orthomosaic generated from the data that was processed in Pix4D. This map also includes a locator map to show where within the state the study took place. Overall the final product turned out well. there is enough overlap between all of the photos to create a good mosaic. When compared to an actual satellite image, the difference in quality can be observed, however with the orthomosaic overall the quality is good.

Figure 6
Othomosaic (Top) compared to Satellite image (Bottom)

The second map was a DSM map that showed the surface elevation of the study area. A hillshade generated using the DSM which was created during the image processing. This was overlaid on an imagery basemap which was made 40% transparent so it can provide spatial reference but not distract from the DSM. The DSM was given a red to blue diverging color ramp. Areas  of high elevation on this map can be somewhat deceiving because many of those areas are trees.

Overall the Pix4D software is easy to use, however it should be noted that for this lab a very small UAS data set was used. Even with this small size processing took roughly twenty minutes. With larger data sets the processing may take several hours. 

Conclusion

UAS data collection and image processing is becoming a very high demand geospatial field. These last two exercises have provided the basic information on how to use Pix4D, a UAS imagery processing software, to generate point clouds, DSMs and Orthomasics. These were then imported into shapefiles and mapped with ArcMap software. This lab demonstrated only a few of the several applications of UAS data