A Brief Introduction to UAVs

Introduction

In a previous post I discussed the planning phase of performing a UAV (unmanned aerial vehicle). Today the class met outside to see demonstrations of a few different kinds of UAVs; two roto-copters, a kite, and a rocket.

The roto-copters were equipped with GPS units which can be used to guide the UAV back to its original starting position. This is extremely helpful if for some reason the pilot were to lose visual contact with the UAV. Cameras were also equipped to the UAVs for pictures to be taken. The cameras had a script installed which allowed for them to take a picture once every couple seconds specified by the pilot. Pictures of the roto-copters can be seen below in figures 1-5.

A kite was launched and was equipped with a camera to take still photos. The camera had the same script programmed into it which allowed for a predetermined amount of photos to be taken at a specific interval. The kite had a very stable flight even though the winds were variable. The camera was attached to the string of the kite to and provided straight down shots. An image can be found below in figure 6.

The last UAV was a rocket which was equipped with two cameras which recorded video during the brief flight (figures 7 and 8). Both engines in the rocket did not fire which resulted in the shorter than expected flight.

Flights

Both roto-copters underwent an in-flight calibration which tested out the motors to make sure that the copter was capable of a full flight. Flight times for the copters was around 15 minutes each. Both copters had a range of 1.5 miles but with only 15 minutes of flight it isn't feasible to reach this range.

Figure 1. Pre-flight for one of the roto-copters.

Figure 2.  An image of a roto-copter with 6 propellors that was utilized for a demo. 

Figure 3. A close up of a roto-copter showing a sensor which is connected to a headset that allows the pilot to view where the copter is. 

Figure 4. A close-up of a gimble which when activated keeps the camera level and pointing at the ground. 

Figure 5. A roto-copter in flight. The copters are able to hover to take stable images. They also have very good agility and tight turning radius'

The kite allows for a flight time of however long there is wind and an excellent stable platform for images to be taken with.

Figure 6. The kite with the camera attached to the sting. The camera took a picture every 5 seconds until 90 pictures were taken.

The rocket is incapable of having a pilot because of the nature of it. Below is an image of the rocket and also a video of the flight that I recorded and edited.

Figure 7. The rocket ready to be launched.

Domain and Feature Class Creation for a Micro-Climate Map

Introduction

When collecting data from the field there are many ways to prepare for the influx of data. One of the most efficient ways to store data using ArcMap is to create a geodatabase and to set domains within a feature class. For this exercise a feature class was created which will display information regarding the micro-climate of the University of Wisconsin Eau Claire’s campus.

Part 1. Pre-Planning

A micro-climate map displays descriptive data regarding certain elements of a climate. For this exercise we will be focusing on temperature, dew point, wind speed, azimuth, and direction, relative humidity, notes, and snow depth (assuming snow will not have melted by the time of data collection). In previous exercises data was entered into ArcMap after it was collected but now we will be using ArcPad which is a small scale version of ArcMap which allows for easy data entry into a feature class that can be transferred to ArcMap.

Before data entry occurs it is best practice to set domains on the fields within a feature class. Each domain is set up to set limits on descriptive values such as integers or text fields. These limits can severely cut down on data entry errors. For example if you are entering data for weather it is safe to assume you will not have a temp of 150 degrees. With a domain you can set a range for the data so that errors like these do not occur.

Planning ahead before data collection occurs can save valuable time when processing data. Creating a geodatabase to store feature classes is just one step of data entry. Utilizing domains within the feature class will assist with data entry.

Part 2. Domains and Feature Class Creation

Setting up the micro-climate database for deployment to ArcPad requires several steps. First, a new File Geodatabase must be created within our assignment folder. To achieve this, within ArcMap we connected to our respective folders and right-clicked the folder selection add > new file geodatabase (Figure 1.)

Figure 1. Create a new File Geodatabase. This will contain a Feature Class that will have Domains associated with it for data collection.

Once the Geodatabase is created we can setup domain types by going into the properties section. In ArcMap, right-click on the geodatabase then select properties. The window that appears will allow you to set the domain properties. Within this window use the Domain Name field to enter the different kinds of data which will be collected and give a brief description in the Description field. After entering a Domain Name and Description look at the bottom half of the window in the Domain Properties section. Here is where limits will be set. For Temperature, the Field Type would be Float. Float allows for integers to be displayed with decimals. The Domain Type will be Range since there will be a range of temps collected. The Minimum value depends on the time of year but in Eau Claire it is safe to put down -20 (Fahrenheit) and a Maximum of 99. All other Domain Properties can be left at Default Value. The Coded Values section is for entering one or two letter/digit values which will represent something such as using N for North. Coded Values are suggested for Wind Direction. Figure 2 shows a completed Domains section for this exercise.

Figure 2. Create Domains by setting a Domain Name, Description, and Domain Properties. Coded Values should be used for wind direction or anything else that uses abbreviations.

After the domains have been set create a new feature class within the Geodatabase by right-clicking on the database and selecting New > Feature Class… (Figure 3).

Figure 3. Create a new point Feature Class for the data to collected into.

For the purpose of this exercise we created a Point feature class. Once created, enter the properties of the feature class and select the Fields tab. This will allow you to enter new Fields and to associate them with the domains created earlier. In the Field Name section enter the name of the data to be collected and give it a Data Type. In the Field Properties section below click on the box next to Domain to associate a domain with the new Field Name (Figure 4). Only Domains with the same Data Type will be shown so make sure you remember what kind of Data Type you gave to each piece of data you want to collect.

Figure 4. Associate the Domains with the Field Names. The Field Names should represent the data to be collected. The Domains will set limits to the data that can be entered for each field.

Now that the Field Names have been set and Domains have been associated with them it is now time to prepare for data entry with ArcPad. In ArcPad a base map will be needed so that we can tell where we are when collecting data. This is done by importing a raster of the study area to our geodatabase. The study area for this Micro-Climate is the University of Wisconsin Eau Claire’s campus. Our professor has already acquired a raster for us to use. We were required to import this raster into our geodatabase from his. To import a raster right-click on the geodatabase you want it to be imported into then select Import > Raster Datasets… (Figure 5.)

Figure 5. Import a Raster Dataset to be the basemap that will appear on the ArcMap interface.

Once the raster base image has been imported the geodatabase will contain the necessary components to collect data. One more step must be accomplished before saving the map document; connecting the geodatabase to the map document. To do this click on File in ArcMap and select Map Document Properties… This opens the Map Document Properties window. At the bottom of this window set the Default Geodatabase to the one you just created and check the box next to Pathnames (Figure 6.)

Figure 6. Set the default geodatabase and store relative pathnames. This allows for data to be stored directly into the specified geodatabase and if files get moved around the Pathnames will allow for the files to be retrieved saving precious time.

Save the map document containing the raster and the feature class so that it can be used within ArcPad to map the micro-climate of UWEC’s campus. 

Map Construction for Compass Navigation

Introduction

Land navigation with a map and compass is a useful skill because as we learned last week you cannot always rely on technology. Being able to use a map with a compass removes any need for electronics and lightens the load being brought into the field. The kind of map used for navigation is important because if the map is too busy (containing too many features) it will be hard to read and almost useless. A map suitable for land navigation can be created using very few layers.

The maps created will represent a specific location located in southern Eau Claire, WI, the Priory. The landscape of the Priory is dynamic with the main building being built on a steep plateau. The Priory is presently a dormitory used by students of UW-Eau Claire and is the new home of the UW-Eau Claire’s Children’s Center. A navigation course has been established in the woods surrounding the Priory which will be utilized later on in the semester. The maps created in this exercise will be used when we travel to the Priory to practice our navigation skills.

For this exercise two maps were constructed; one using a geographic coordinate system (GCS) and another using a Universal Transverse Mercator (UTM) coordinate system. These maps were created using ArcMap 10.2 with map data provided from the instructor of the course.

Methods

Data Collection

The first step in creating the maps was data collection. As mentioned above data was provided for the maps with the task of selecting pertinent layers to be included in the map. Numerous layers were provided by the instructor but most of the data was not useful. I chose to use the 5 meter contour lines developed from a USGS DEM, an aerial image to provide an accurate representation of the elevation for the Priory, and a Navigation Boundary which shows the maximum extent of the navigation course. 

I chose these data sets to accurately display the elevation changes over space at the Priory while also showing what the surface actually looks like from above. The contour lines are not as cluttered as a 2 foot interval data set which was provided. A digitized contour map was also provided but was excluded because of how the contour lines were overlaid on plain background which does not accurately display the land. Another data set including a No shooting boundary was excluded. This boundary will be used at a later time when paintball guns will be include in the navigation course but for now it can be left off the map. 

Map Creation

Once the 5 meter contour lines, the aerial image, and the navigation boundary were displayed in ArcMap each data set was projected to the UTM zone 15 system. UTM is a projected coordinate system which uses a 2-dimensional Cartesian coordinate system to give locations on the surface of the Earth. UTM system is not a single map projection but a collection of 60 zones(figure 1).

Figure 1. A map of the world with all 60 UTM zones overlaid. Each zone covers a 6 degree band of latitude on the secant transverse Mercator projection.

UTM zone 15 was chosen because of how Eau Claire, WI is located close to the central meridian of the zone and the zone is measured in meters instead of degrees like how the WGS 1984 system is measured. 

 

WGS (World Geodetic System) 1984 was used for the second map containing the same layers as the one using the UTM zone 15 system. WGS 84 is a standard for use in cartography, geodesy, and navigation and is the reference coordinate system used by the Global Positioning System. This system is the result of a unified geodetic system for the whole world because of lack of inter-continental geodetic information, the inability of the large geodetic systems to provide a worldwide geo-data basis, a need for global maps for navigation, aviation, and geography, and other reasons. Figure 2 below shows the WGS 84 system.

Figure 2. Image of the world displayed in the WGS 84 coordinate system. Notice how this image and the UTM image are similar. The WGS 84 system is measured in Degrees whereas the UTM is in meters.

This projection was chosen because it is the system used by the Global Positioning System which will be utilized by using a handheld GPS for part of the navigation. 

Grid Creation

For the purpose of the navigation maps we were instructed to use an 11x17 inch landscape orientation. In order to do this the layers were displayed in ArcMap using Layout View. To do this select change layout in the layout toolbar. Click the North American (ANSI) Page Sizes tab and finally the Tabloid (ANSI B) Landscape.mxd. This template has a default 11x17 inch size (Figure 3).

Figure 3. The Select Template window with the Tabloid (ANSI B) Landscape.mxd template highlighted. This template is defaulted to 11x17inches which will make for a large map but one that is still easily carried.

After the layout is selected the map can be repositioned and adjusted to suit the user and features such as a title, scale bar, north arrow, and other map features can be added. For the purpose of plotting the navigation points a grid must be used to provide accurate placement of points. Two grids were created, one for the UTM zone 15 projection and one for the WGS 84 system. The UTM zone grid is in meters and the WGS grid is in degrees. 

To create the grids there are many steps which must be done.

1.   With the map positioned within the layout view navigate to properties of the data frame

2.   Click the Grids tab and then New Grid…

3.   Within the Grids and Graticules Wizard pick either Graticule or Measured Grid. Then name the grid. For the purpose of these instructions I’ll be using the Measured Grid. Figure 4 will show the windows that should be on the screen at this point.

Figure 4. Windows showing the first three steps of grid creation in ArcMap with red numbers indicating at which step to click or make adjustments.

  4.   Click next and then properties to select a coordinate system

  5.   Then decide on an interval for the grid. For my grid I chose a 50 meter interval on the X and Y axis

  6.   After the interval is chosen the user is able to make changes to the aesthetics of    the grid. Once finalized click Finish in the wizard to make the grid appear in the layout.

Both grids are created in a similar fashion with the only major difference being the coordinate system that is chosen within the wizard.

 

Results

The resulting maps of the study area with the grid and layers are below. Figure 5 is the map with the UTM zone 15 system and figure 6 is the WGS 84 system.

Figure 5. Priory map with 5 meter contours, a transparent aerial image and a navigation boundary. The grid on the map is measure in meters with 50 meter intervals on the X and Y axis.

Figure 6. Priory map with 5 meter contours, a transparent aerial image and a navigation boundary. The grid on the map is measure in degrees with 2 second intervals on the X and Y axis..

Compass Navigation

In order to use the maps created to their fullest potential the use of a compass for navigation must be learned. A standard compass (figure 7) will be utilized for navigation at the Priory. To use the compass there are a series of steps which will get the most out of what the compass can do.

Figure 7. A compass with many features that is identical to what will be utilized for the orienteering activity. The rotating Housing With Degree Dial will be referred to as a "bevel" later in the directions.

  1.   Place the compass on the map having the direction of travel arrow (DTA) pointing in the desired direction of travel from your starting point to the ending point.

  2.   With the compass still on the map rotate the bevel so that 0 degrees on the bevel is pointing to the Northern part of the map. Use the grid lines to help point the bevel north.

  3.   Finally, take the compass from the map and hold it steadily in front of one’s self. Rotate until the red end of the magnetic arrow fits into the holler orienting arrow. This is commonly referred to as being “red in the shed”. As long as you maintain this red in the shed you will be moving in the desired direction of travel to approach the destination.

 

Discussion

The creation of the maps and grid will prove beneficial for navigation practices because of how easily readable the maps are. With only showing an aerial image and contour lines as well as a navigation boundary anyone should have an easy time navigating around the Priory. 

A legend was not included on the maps because the only main feature that was necessary to label was the contour lines. The navigation boundary, although being a layer on the map, provides nothing more than an extent for the map similar to a state or county boundary. The contour lines are clearly labeled in the heading of the maps as being 5 meter intervals. 

With the aerial image being more transparent it is easier to plot points than if it were to be its full color. Having it transparent also allows for the contour lines to stand out showing the landscape more clearly.

 

Conclusion

Both maps were created encompassing the Priory in southern Eau Claire, WI as the study area showing 5 meter contour lines, an aerial image, and a navigation boundary. These maps will be utilized in an orienteering activity at a later point in the semester. 

The maps look good on a computer screen but once printed out and worked with in the field will their true strength be known. It is easy to make a map look good on a computer but nothing can truly emulate a hard copy of a map besides a hard copy. By knowing the assignment and being familiar with the region I selected what I believe to be pertinent data for the map.