Building Maps with Pix4D

Introduction


* Why are proper cartographic skills essential in working with UAS data?

Cartographic skills are essential for working with UAS data because it makes the reader have a better understanding of the data.  Having a North Arrow, scale bar, locator map, watermark, and data sources give the reader everything they would need to understand.  It is also important to make sure data created and presented can not be stolen as easily, and it also gives the reader the ability to look up anything or look at data used.


* What are the fundamentals of turning either a drawing or an aerial image into a map?

The fundamentals of turning a drawing or an aerial image into a map involve a few different steps.  The first step is to add a north arrow, scale bar, watermark, sources and a title.  The most important is the north arrow and the scale bar.  Although, most of this is not useful without having a locator map as well.

* What can spatial patterns of data tell the reader about UAS data? Provide several examples.



* What are the objectives of the lab?

The objects of the lab include using processed Pix4D to create a map that meets the criteria for the fundamentals of turning an image into a map. The objectives also includes using a hillshade tool, and learning about the difference between a DSM and a DEM.  Finally, this lab also includes understanding the patterns found in a orthomosaic, reporting statistics between the DSM and DEM, and understanding how UAS data can be used as a tool to enhance cartography for the user.

Methods

Metadata:
Platform: DJI Phantom 3 Advanced
GPS precision level: sub meters
Drone Sensor: Sony 16 Megapixel Camera
Altitude of project: 60m
Coordinate system: WGS 1984 UTM Zone 15N
Projection: Wisconsin State Plain
Date: 3-7-2016

The first step is to open up the orthomosaic and the DSM into ArcMap, and then create pyramids and generate the statistics for each data set. a DSM is a digital surface map compared to a DEM which is a digital elevation map.  A DSM includes many values for elevation which includes trees, plants, and power lines, etc.  A DEM involves just the ground surface force creating the raster.  Georeference Moasic is using ground control points to lock down the image compared to orthorectified moasic which is when images from a drone are stitched together based on tie points done by a computer.  Orthorecified moasic is not nearly as accurate as a georeferenced moasic due to the ground control points.  The statistics created from the DSM are important because it will show the value of the ground elevation and give all the data needed that may be presented.  Finally, to use a hillshade on a DSM use the search tool on and search for hillshade. In the hillshade window delineate the regions of the DSM.  Now the last step is to create a map with all of the fundamentals of map making involved with it. The statistics found within the properties of each group represents the elevation of the ground at different points.

Figure 1: A Map of Sportfield, Wisconsin showing the elevation based on a DSM and Orthomosaic.

Figure 2: This is an oblique view of the sportsfield.  The north arrow gives the direction in the top left corner. 

Results
* What types of patterns do you notice on the orthomosaic?

On the Orthomosaic there are a few different patterns the first would be  that there is a straight line of trees along with a very gradually increasing slope going from South to North.  The map is almost split up right down the middle where it starts to slope down compared to gaining elevation.


* What patterns are noted on the DSM? How do these patterns align with the DSM descriptive statistics? How do the DSM patterns align with patterns with the orthomosaic?

The pattern noticed on the DSM is that there are almost lines going across which indicate the elevation.  This aligns with the statistics due to those numbers also showing the elevation.  There are also the tree and vegetation that can be seen which lines up with the orthomosaic.

* Describe the regions you created by combining differences in topography and vegetation.

I created a region that involved the top area and then one for the bottom area.  I created two separate ones for the vegitation therefore, not allowing it to interfere with the rest of the map.


* What anomalies or errors are noted in the data sets?

The trees and vegetation could make the elevation numbers off due to them being higher up and all being the same height due to how the images were taken.  Another error would be having poor data in the top left of the image.  This would create errors that could be fixed if there were more pictures to be processed in that area.  There are also not any GCP to tie any of the parts down to the actual basemap.


* Where is the data quality the best? Where do you note poor data quality? How might this relate to the application?

The data quality is the best near the middle of the image.  This is due to how many images are being stitched together in that area.  The poor data is in the top left part of the image.  This may be due to having lack of images up there to create a better area of data.  This may relate to the application because it may not give an exact elevation compared to the other areas.

Conclusion

UAS data is a great tool to complement any GIS user.  It has the ability to take high quality data to create high quality numbers to solve many problems.  It is also useful because of the high level of accuracy it has.  It does have limitations as it cannot fly during most types of bad weather, and relies on day time to capture data when light is needed.  When the user is working with the data the user should know that even if the program can process the data, it does not mean that it will be correct numbers.  There is a lot of steps that go into solving a problem and the quick way will most likely be the garbage out method.  This data could be combined with GCP to help tie down the points even better than they are with the platforms GPS.

UAS Platform Consulting Report

Introduction

There are many different kinds and styles of unmanned aerial systems created every year with their own unique take on the build.  Since the beginning of the boom of UAS the companies with the best build and highest quality are breaking their way through the market.  A few of the brands that stick out of the pack would include the Parrot, DJI, Yuneec, and Kespry.  This four companies have a high anticipation for the 2017 market.  Many drones are build with a fix wing or quad copter.  Each has their own strengths and weaknesses.  Comapny XXXX has asked to be consulted on what type of platform to purchase to do volumetrics on a sand mine in Western Wisconsin.  This can be a daunting task due to the amount of variability out there.  Therefore, getting the details of the project will be the first step.  The company want to be able to use a UAS to determine the amount of volume within a sand pile which will take roughly 20-30 minutes of flight time.  Therefore this report will be going into details of a low level/hobbyist drone, mid level, and upper level commercial drone.  For this report a low level drone costs $500-3000, a mid level cost $5000-10000, and a high level commercial costs $50,000 - 150,000.

Low Level

The low level drone picked for this project would be the DJI Phantom 3. The DJI Phantom 3 has four different models that can currently be purchased between $500-$999.  This includes the Standard, 4k, Advanced, and Professional. The standard was created for people on a budget and released after the Advanced and professional models were already created.  The standard does not have the 4k video capability, and the Phantom 3 standard comes with a 2.7k video or 720p.  This also uses the Panasonic image sensor instead of the Sony Exmor R sensor which comes on the more expensive models of the DJI Phantom 3 Advance, 4k, and professional models.  The control made for the standered model comes with a control that looks like the one from the DJI Phantom 2 and does not have an easy way to mount an Ipad to the controller.  It also does not have any custom buttons and does not have any dedicated buttons for the video playback.

The 4k DJI Phantom was realeased with the capability of 4K playback, and has the more expensive controller allowing it to easily connect to an Ipad or Iphone.  It also has all the capabilities of the standard model.

The Phantom 3 Advanced was part of the first release with the DJI Phantom 3's.  This model does not have 4k video and therefor uses the same camera as the standard model.  The difference between this model and the two listed above is that this uses a technology called Lightbridge.  This technology offers a more dependable video and control signal.  With the Lightbridge technology the DJI Phantom 3 Advance can travel up to 5000m or 3.1 miles from the pilot.  This is 4.1 times farther than the phantom 3 4k and it is 5 times farther than the standard model.  Therefore even though this model does not have the 4k video is comes with more impressive technology allowing greater control over the drone. The Advance also has 720p play back to the streaming goggles compared to the 480p in the two listed above.

The last DJI Phantom 3 model is the professional model.  This model also includes the 4k camera, 720p playback, and Lightbridge GPS technology.  The difference with this model is that it comes with a 100W charge with allows the professional model to be charged in less than an hour compared to all the others which take up to an hour and twenty minutes.  This is the most expensive of the models at $999, but has great reviews at the low level tier.

All the models also allow the user to create a point of interest which the Phantom 3 will continuously face it as the user flys or by circling around the object.  It can also be programmed to follow the user as a 'personal film crew.'  it can also be programmed with flight paths, and has intelligent orientation control allowing the user to use the easiest mode to fly with.  The DJI Phantom 3 also has LED lights which indicate the battery level.  Parts are easy to order from the DJI Store and reviews suggest that the DJI is not hard to fix when parts break as well.

Figure 1: The video above explains how to set up and get started with the DJI Phantom 3 Professional.  It goes over the app used on the Iphone and how to use the controls with the device.

Mid Level

The Freefly Systems Alta 6 UAV costs $11,995.00, which is slightly over budget for the mid level, but this is a very impressive drone.  It is made with 8 motors, allows the user to use a 9.1kg payload to allow expensive cameras to be mounted onto the platform.  This Drone also allows the user to put the camera on top or on the bottom depending on the needs of the drone.  This drone comes with Freefly's own flight control systems and it also works with a range of different transmitters so when upgrading to this drone there may not be a need to buy a new controller.

 The flights modes that can be used with this drone include manual, height hold, climb rate control, position hold, ground speed control, return-to-home, and auto-l;and.  This drone also works with first person video systems.  The freefly ALTA has a very robust hard case.  To take out the drone just unfold and put the battery in and it is ready to go.

The system comes with weather-resistant electronics and has a silent drive technology built into the motors. This drone can fly up to a mile away, but it can be more depending on the weight.  The sensor used on this drone is up to the user since it can be attached using the gimble. The flight time on this drone is around 40 minutes.

This drone is great for users that want to get unique angles and carry high end cameras that weigh more than the average drone can carry.

Figure 2: The video above shows the Freefly Systems Alta 6 UAV.  This offers some video of the unboxing and review of the system.

High Level

The Penguin B Platform made by UAV System Integrators.  This platform currently holds the world record for endurance at 54.4 hours of flying time.  It has a fuel injected engine that allows the Penguin B to fly up to 20+ hours for normal use.  It can also carry a 10kg payload, and has a 80W on-board generator. The Penguin B has been sold since 2009 and has over 140 different customization. This drone is mostly used with research organizations and universities due to the price and the customization that can be done to fit the research being conducted.

The Penguin B Platform is a fixed-wing UAV which is why it has such a longer flight time, and also gives it the ability to have such a large payload.  This platform is shot into the air using a catapult, car-top, or runway take off to give the platform enough velocity to keep it in the air.

This drone comes with free Piccolo autopilot configuration files and comes with a four day integrator training.  This UAV flies at speeds up to 36m/s, but the general cruise speed is 22 m/s.  It also comes with the ability to deice the wings with its heated pitot probe.  It comes with quick release joints which allow fast and quick assembly.  the Penguin B has the option to have heavy duty land gear to land on rough terrain.  The platform also comes with the portable control station which is compatible with Cloud Cap Piccolo, Procerus Technologies Kestrel, Micropilot autopilot systems. This platform can carry any type of sensor as long as it fits into the universal mount on the drone.

This is a highly advanced UAV that comes with over 140 different customization, and if needed the company can also come up with different ones for different needs that may not have been met yet.

 

Figure 3: This video shows a take off and landing from a car mount for the Penguin B UAV.


Conclusion

The best option for the project at hand would be the DJI Phantom 3 Advanced model.  This one was chosen because of the price point and capabilities.  It matches the amount of flight time needed.  It has a camera that has a high enough resolution to use for calculations.  It also has the ability for other projects as well.