Introduction:
The purpose of this lab was to familiarize us with processing data in the Pix4D software in order to create maps later with ArcGIS pro. In this lab Pix4D is utilized in order to construct a point cloud, create a true orthomosaic, and generate a digital surface model. Pix4D is currently the most popular Structure From Motion Multi-View-Stereo software for constructing point clouds. Pix4D and similiar software are integral to UAS because they allow you to create useful maps and orthomosaics from what would otherwise be plain aerial photographs.
Methods:
I processed both the Wolf_Paving_UASdata and the Flight1_Nadir datasets. The first step I took in this lab was to make sure that my files were managed appropriately. Three folders are created; collection, processing, and analysis. The collection folder contains the images, ground control points, and based station data. The processing folder is where the data is processed. The analysis folder is where the actual GIS data is created and analyzed. After creating the appropriate folders it is time to name the Pix4D file. The names for both files I created included the date, site, sensor, altitude, and correction info.
Next it is necessary to select the images you wish to process. It is important during this step to make sure the program is using the correct shutter model. In both cases it is necessary to change the shutter model to "rolling shutter". You also need to select an output coordinate model. The model used for this lab was WGS84/UTM.
The processing will be done in two separate parts. It is important to note that initial processing is done separately from the generation of the point cloud and orthomosaic. After reviewing the processing options it is time to begin initial processing. This takes some time, and a quality report is created once initial processing is finished. Figure 1 shows the initial processing phase. Figure 2 shows some of the information from the quality report. Figure 3 shows what the project looks like after initial processing.
After the initial processing is finished it is important that the check box for this operation is un-selected. For the second part of processing the other two boxes "Point Cloud and Mesh" and "DSM, Orthomosaic, and Index" are selected. After the second round of processing the orthomosaic and point cloud have been created. Figure 4 shows the Ortho and DSM generated for the first data set.
Figure 5 shows the Ortho and DSM generated for the second data set. Figures 6 and 7 show the ortho and DSM created in previous labs without GCPs.
(Figure 6)
After the second round of processing is finished it was necessary to use Pix4D in order to create an animation of the orthomosaic. Different way points are used in order to create a POV video animation. Figure 8 shows the animation created within Pix4D. Figure 9 shows the process of selecting way points for the video.
Conclusion:
Pix4D is important when it comes to processing UAS data because it allows you to turn aerial images into useful information and models with little manual effort. One of the drawbacks of Pix4D is the processing time. For both data-sets initial processing took 30 minutes to an hour. On the other hand Pix4D is very easy to use and incredibly user friendly. I appreciated this lab because it allowed for me to better understand how data is processed before it is used to create maps in other programs like ArcGis Pro.
Methods:
I processed both the Wolf_Paving_UASdata and the Flight1_Nadir datasets. The first step I took in this lab was to make sure that my files were managed appropriately. Three folders are created; collection, processing, and analysis. The collection folder contains the images, ground control points, and based station data. The processing folder is where the data is processed. The analysis folder is where the actual GIS data is created and analyzed. After creating the appropriate folders it is time to name the Pix4D file. The names for both files I created included the date, site, sensor, altitude, and correction info.
Next it is necessary to select the images you wish to process. It is important during this step to make sure the program is using the correct shutter model. In both cases it is necessary to change the shutter model to "rolling shutter". You also need to select an output coordinate model. The model used for this lab was WGS84/UTM.
The processing will be done in two separate parts. It is important to note that initial processing is done separately from the generation of the point cloud and orthomosaic. After reviewing the processing options it is time to begin initial processing. This takes some time, and a quality report is created once initial processing is finished. Figure 1 shows the initial processing phase. Figure 2 shows some of the information from the quality report. Figure 3 shows what the project looks like after initial processing.
(Figure 1)
(Figure 2)
(Figure 3)
Figure 5 shows the Ortho and DSM generated for the second data set. Figures 6 and 7 show the ortho and DSM created in previous labs without GCPs.
(Figure 4)
(Figure 5)
(Figure 7)
After the second round of processing is finished it was necessary to use Pix4D in order to create an animation of the orthomosaic. Different way points are used in order to create a POV video animation. Figure 8 shows the animation created within Pix4D. Figure 9 shows the process of selecting way points for the video.
(Figure 8)
(Figure 9)
Pix4D is important when it comes to processing UAS data because it allows you to turn aerial images into useful information and models with little manual effort. One of the drawbacks of Pix4D is the processing time. For both data-sets initial processing took 30 minutes to an hour. On the other hand Pix4D is very easy to use and incredibly user friendly. I appreciated this lab because it allowed for me to better understand how data is processed before it is used to create maps in other programs like ArcGis Pro.
