Aero-M

The Aero-M is one of two aerial mapping platforms introduced by 3D Robotics, it is a fixed wing aircraft . It is designed to have everything that you need for mapping straight out of the box and as well as having standard elements includes:

• Pixhawk autopilot system.
• Canon SX260 with custom 3DR EAI software and fixed mount.
• Pix4Dmapper LT 3DR Edition, which is only capable of creating two-dimensional maps.
• It also includes a custom-designed hard-top travel case.

Additional elements that can be purchased include:

• An upgrade to Pix4Dmapper Pro 3DR Edition, this allows the creation and export of DSM (Digital surface models) and terrain models as well as orthomosaic editing. This costs an extra $5000.
• An OSD (On screen display)/FPV (First person view) system which uses a Sony HAD 520 line camera to stream video to a viewing device while a MinimOSD on-screen-display module superimposes live telemetry data onto the video feed. This costs an additional $249.99. A monitor needs to be purchased to view the data.

It has a 40 minutes flight time and can record up to 250 acres in one flight.

http://store.3drobotics.com/products/aero-m/

The basic price of the Aero-M is $5400, with all of the additions it costs $10724.99. According to 3D Robotics this is providing “advanced mapping capabilities at a price five times less than that of our nearest technological competitor”..

The 3DRobitics Aero-M fixed-wing drone

Example
An example of an photo-mosaic map creating using the Pix4Dmapper software from an aerial platform.

Potential
The flight time of the Aero-M is significantly longer than the other mapping system, X8-M, which demonstrates the benefits of using a fixed wing platform over a multi-rotor platform which needs to power all of the rotors to stay in the air.

The multiple overlapping photographs taken by the camera can be used to create digital elevation models (DEM) these are an important element is archaeological prospection, although they can be created with LIDAR data a much higher level of detail can be generated from those created by photogrammetry using UAV (Unmanned Aerial Vehicle) photographs. The overalapping photographs can also be stitched together to create a high quality mosaic. They can also be used to create a 3D model of the site.

3d Robotics is part of the open-source hardware and software community based at DIY Drones which can help with all aspects of drone construction and use.

The Pixhawk autopilot system allows the easy creation of a flight path by selecting points on a map displayed in the mission planning software. By selecting a polygon around the area the software can create a grid flight pattern to fly; the altitude, camera type and overlap of images can also be set which alters the amount of times the aerial vehicle flies across the area under study.

Limitations
The problems with using a fixed wing platform for mapping are, takeoffs and landings, and tree cover around the area under study; the X8-M multi-rotor platform has the ability to turn on the spot.

Although the Aero-M is an expensive purchase it appears to still be a bargain.

The extra $5000 for software is also a lot, there are other cheaper options such as Agisoft Photoscan Professional which costs $3499.

It comes with a Canon SX260 camera which is a cheap, compact, lightweight, digital camera that fits well into the system; but it has neither the optics nor the image size (12.1 megapixels vs. 24.2 megapixels) of a higher quality digital SLR camera, so information will be lost from photographs that could be taken by a higher quality camera. The Aero-M platform can carry 500g so it will be able to carry higher specification digital SLR cameras than the Canon, allowing higher definiti0on pictures to be taken.

It is designed solely for mapping so the camera is in a fixed position and can only record downwards.

Although accuracy may have its limitations, by placing targets on the ground in a grid pattern and recording their position with GPS (Global Positioning System) the accuracy can be improved, and as the DEM is accurately georeferenced it can be imported accurately into GIS software.

X8-M

The X8-M is one of two aerial mapping platforms introduced by 3D Robotics, it is a multi-rotor UAV (Unmanned Aerial Vehicle) with a fully redundant propulsion system thanks to the fact that four of the propellers face up while the other four face down on the same struts, so if one fails there is still propulsion from the other. It has the ability to conduct mapping at a low altitude, at a low speed and at a high level of accuracy which is impossible to capture by manned flights or using satellite imaginary.

It is designed to have everything that you need for mapping straight out of the box and as well as having standard elements includes:

• Pixhawk autopilot system.
• Canon SX260 with custom 3DR EAI software and fixed mount.
• Pix4Dmapper LT 3DR Edition, which is only capable of creating two-dimensional maps.
• It also includes a custom-designed hard-top travel case.

Additional elements that can be purchased include:

• An upgrade to Pix4Dmapper Pro 3DR Edition, this allows the creation and export of DSM (Digital surface models) and terrain models as well as orthomosaic editing. This costs an extra $5000.
• An OSD (On screen display)/FPV (First person view) system which uses a Sony HAD 520 line camera to stream video to a viewing device while a MinimOSD on-screen-display module superimposes live telemetry data onto the video feed. This costs an additional $249.99. A monitor needs to be purchased to view the data.

The basic price of the x8-M is $5400, with all of the additions it costs $10729.98. According to 3D Robotics this is providing “advanced mapping capabilities at a price five times less than that of our nearest technological competitor”.

The X8-M has a flight time of 14 minutes covering 25 acres.

https://store.3drobotics.com/products/x8-m

Potential
The multiple overlapping photographs taken by the camera can be used to create digital elevation models (DEM) these are an important element is archaeological prospection, although they can be created with LIDAR data a much higher level of detail can be generated from those created by photogrammetry using UAV (Unmanned Aerial Vehicle) photographs. The overalapping photographs can also be stitched together to create a high quality mosaic. They can also be used to create a 3D model of the site.

3d Robotics is part of the open-source hardware and software community based at DIY Drones which can help with all aspects of drone construction and use.

The Pixhawk autopilot system allows the easy creation of a flight path by selecting points on a map displayed in the mission planning software. By selecting a polygon around the area the software can create a grid flight pattern to fly; the altitude, camera type and overlap of images can also be set which alters the amount of times the aerial vehicle flies across the area under study.

Example
An example of an photo-mosaic map creating using the Pix4Dmapper software from an aerial platform.

An example of this type of work with a multi-rotor UAV can be seen here.

While a 3D model created from images captured from a hexacapoter can be seen here on the p3d.in 3D model sharing website.

Limitations
Although the Aero-M is an expensive purchase it appears to still be a bargain.

The flight time of 14 minutes is quite small for a large area survey, but multiple batteries could be carried and mapping done in stages.

The extra $5000 for software is also a lot, there are other cheaper options such as Agisoft Photoscan Professional which costs $3499.

It comes with a Canon SX260 camera which is a cheap, compact, lightweight, digital camera that fits well into the system; but it has neither the optics nor the image size (12.1 megapixels vs. 24.2 megapixels) of a higher quality digital SLR camera, so information will be lost from photographs that could be taken by a higher quality camera. But the X8-M platform can only carry 200g so it is not capable of carrying these heavier cameras which weigh 530g (in the case of the Nikon D5300) so the quality is probably at the highest level possible.

It is deigned solely for mapping so the camera is in a fixed position and can only record downwards, a camera gimbal could be easily attached to the UAV frame allowing the camera to view a multiple angles and so record much more than just what is below it.

Although the accuracy of any DEM or photogrammetry model may have its limitations, by placing targets on the ground in a grid pattern and recording their position with GPS (Global Positioning System) the accuracy can be improved, and as the DEM is accurately georeferenced it can be imported accurately into GIS software.

GoPro HERO

The GoPro HERO is a new budget camera in the GoPro range. It takes 5MP (mega pixels) photos which can be recorded up to 5 frames a second and records video at 1080p30 and 720p60. With its rugged case it is waterproof to 40m.

The interface has been made easier with the new QuikCature mode which allows the user to power on the camera and start recording by pressing a single button. Pressing once records video, while holding the button down for 2 seconds starts to capture time lapse photos.

http://shop.gopro.com/EMEA/cameras/hero/CHDHA-301.html

The GoPro HERO costs £99.99.

Potential
The GoPro HERO has much of the same potential as the GoPro HERO4 which can be read here.

At only £100 its potential for budget wearable technology in archaeology is enhanced greatly, with the cost of 3 GoPro Heros being less than 1 GoPro Hero4.

Limitations
Up until now one of the major limitations of the GoPro has been the price, but with a GoPro costing £99.99 this drawback has been removed.

There are limitations to this budget model though, the camera is only 5MP as opposed to the GoPro HERO4 which is 12MP, which is quite a low level of recording for a modern digital camera. It will limit the amount of information recorded in a photograph, and hence any 3D models created from the results.

GoPro HERO4

The GoPro HERO4 is a new camera in the GoPro range, it consists of two separate models, the silver and the black.

Silver

The silver model includes a built-in touch-screen display, previously this had been available as an extra which connected to the back of the camera, the black model does not come with this.

It captures photographs with its 12MP camera at speeds up to 30fps and records video at 1080p60 and 720p120.

Black

Professional Video up to 4K30

It captures photographs with its 12MP camera at speeds up to 30fps and records video at 4K30, 2.7K50 and 1080p120.

Both models have built-In Wi-Fi + Bluetooth allowing connection and control from other devices using the GoPro App, Smart Remote2 and more.

With their rugged case they are waterproof to 40m.

The silver version of the camera is £289.99 while the back is £369.99.

Potential
The GoPro camera was designed with the extreme sports industry in mind, but it has since find a place in a number of other disciplines.

The size, weight and portability of the GoPro camera has meant that is had become the mainstay of the UAV (unmanned aerial vehicles) industry with the camera becoming standard on many quadcopters. The user can see what the camera sees by either using the on-board wi-fi and an app on tablet computers or phones; or a fpv (first person view) system which can be sent wirelessly to either a video monitor or video goggles. Motorised gimbals can be used to both, stablise the camera to remove any shake caused by the UAV, and to change the direction the camera is pointing in mid flight.

The GoPro also has great potential as wearable technology in the trench:

• The camera comes with a number of mounts out of the box, including ones that can attach to hardhats, but other mounts are available including a chest harness. These could be used to record the excavation process by attaching GoPro camera to the archaeologist excavating; the video could be used to record video but the individual video frames, or photographs, could be used to create a 3D photogrammetry model of the excavation. The combination of head and chest mounted camera may provide enough images to make an accurate model of the excavation. The rugged plastic housing can protect the camera from anything that it comes across in the trench.
• If a complicated or important excavation was being undertaken or an important artifact was being lifted the excavator could have a live conference with an expert who could advise them on the best way to excavate it.
• Experimentation with aspects of wearable technology has been undertaken on the Portus Project in Italy under the auspices of the University of Southampton.

The use of the GoPro is not limited to a single camera, the Dual HERO System is a case that allows two GoPro camera to be put side by side which allows 3D footage to be created using the GoPro Studio editing software.

The 360heros series of GoPro mounts clips a number of cameras together allowing spherical video recording with up to 14 GoPro cameras, the videos recorded can be stitched together in video stitching software to create immersive 360˚ videos. Mounts are available for everything from the top of helmets, to UAVs, underwater recording and even for recording 360˚ 3D with 14 GoPro cameras.

360Heros 360° GoPro mount

The system can record immersive videos on the ground, in the air and underwater which can viewed in a video player online – http://video.360heros.com/website/users/webplayer/videodetails.php?vid=59

The Freedom360 provides a similar system.

A GoPro has even been attached to a shovel while archaeology is being undertaken – https://www.youtube.com/watch?v=ht0RR94O9jY&feature=youtu.be

It has been used in underwater test of sfm (structure from motion) – http://arc-team-open-research.blogspot.co.uk/2013/03/extreme-sfm-underwater-archaeology.html

Limitations
The HERO4 Black provides the user with a highly portable camera capable of recording 4K video, it does however come at a high price which limits the potential of using multiple cameras in an immersive recording system, the cheaper HERO does provide this opportunity however.

IRIS+

The IRIS+ is the latest in a range of open source UAVs (Unmanned Aerial Vehicles) from 3D Robotics, an open source hardware and software company. It is designed to carry the GoPro cameras, comes with an autopilot system and provides 16 minutes of flight time fully loaded with camera and gimbal.

It improves on the previous version of the quadcopter.

• 16-22 minutes flight time
• Payload capacity 400 g (.8 lbs)
• Follow me technology

https://store.3drobotics.com/products/IRIS

It comes with an open source autopilot system developed by Pixhawk which allows mission planning involving flight between waypoints and automated grid pattern flight which takes into account the type of camera used.

A number of different free software solutions can be used on different platforms to program the UAV: Droidplanner 2 software on the Android , Mission Planner on Windows and APM Planner on OSX operating system.

The Pixhawk autopilot system means that the UAV can run automated missions recording topographical features to create a digital elevation model. This software also enables the quadcopter to use Follow ME technology which follows the operator, altering the camera angle with the gimbal when necessary.

What adds additionally to the usefulness of this autopilot system, is the fact that it is not tied to the UAV, it can also be used on other types of copters, planes, ground rovers, cars and boats – https://pixhawk.org/modules/pixhawk.

The IRIS+ costs $960 with a 2-axis gimbal.

Potential
The IRIS+ is a high quality budget quadcopter with many useful abilities out of the box, such as an autopilot, which other systems do not. The similar DJI Phantom 2 series requires additional hardware and software which attaches to the UAV system – DJI iOS Ground Station inc 2.4Ghz Data link and Bluetooth Module – and costs an additional £124.

3D Robotics is a company which is part of a large amateur Unmanned Aerial Vehicles community providing expertise in all aspects of the hardware, software and flying and photography skills. In fact the co-founder of the company, Chris Anderson, also founded the website DIYDrones.com.

The release of this may have been the reason the market leader in camera drones/quadcopters, DJI, reduced the prices of their quadcopters, some by as much as $200 – http://www.dji.com/info/news/phantom-2-series-price-drop

Limitations
As it is a quadcopter it is limited to lifting cameras the size of a GoPro.

AirDog

The AirDog is another Kickstarter auto-follow drone “designed for sports enthusiasts, outdoor fans and indie moviemakers”. Unlike the similar HERO+ the AirDog doesn’t use a smartphone as the control interface for the drone to follow, but instead it uses an AirLeash. The system uses the Pixhawk autopilot system.

https://www.airdog.com/

The AirLeash comes with a number of modes.

• Auto-follow – where the AirDog follows the user.
• Relative position follow – where the AirDog retains a set distance to the user while following.
• Follow track – where a route is recorded by flying the AirDog which can then be repeated in the smartphone app.
• Hover and Aim – where the AirDog hovers in one position while following the movement of the AirLeash.
• Circle – where the AirDog circles the AirLeash at a set distance and altitude.
• Look down – the AirDog will record action below it.

Although the AirDog can be controlled completely by the AirLeash the iOS and Android apps allow the distance, height, and angle to be controlled. It carries a GoPro camera in its protective plastic case within a 2-axis gyro-stabilized gimbal.

http://www.bbc.co.uk/news/technology-28178230

The system cost $1,295 with a 2-axis gimbal, although this appears to be a pre-order reduction from $1,495. An additional Airleash can be purchased for $295. The AirDog has a 10-20 minutes flight time depending on the speed it is flown at.

Potential
Both the AirDog and similar system, the Hexo+, have the ability to follow a person carrying a smartphone or other device, keeping them in frame for the whole time frame of a video would seen to have great potential for the recording of site tours, which could now be recorded automatically from different altitudes showing the whole or parts of an excavation. The audio could be recorded with a digital recording device attached to the tour guide, with the audio and video being combined in post production.

They would also have the potential to record fieldwalking and exploration looking for new sites in remote regions.

The BBC has already begun to used UAV systems in the recording of news items – http://www.bbc.co.uk/news/business-24712136 – http://www.bbc.co.uk/blogs/researchanddevelopment/2012/04/collab-soton-uav.shtml – http://www.bbc.co.uk/programmes/n3csw972

Not only is the AirDog impact resistant, it is designed to be flown through wind, waves, rain, sleet, and snow which should cater for the British weather which would limit the flight of other systems. It’s design also allows it to fold up and fit into a backpack, making it very portable.

Limitations
The AirDog is specifically designed for autonomous flight so it does not come with an RC (Radio Control) Controller, it can however be switched to manual and an RC Controller bought separately can be used to control it like a standard UAV, although this obviously adds to the cost.

The recently released IRIS+ quadcopter has limited the usefulness of any small UAV with “follow-me” technology, as not only is it a system with an RC controller and an autopilot that can be used to photographically map areas, but the system also has “follow-me” technology which matches that of other systems. It closely matches the lowest price of the AirDog as well.

The limitations of the system would be closely linked to the limitations of the GoPro camera which it uses to record.

The AirDog project rejected the use of smartphones for a number of reasons:

• Problems with using smartphones in extreme conditions – this is unlikely to be a problem.
• The average smartphone has only a 5-10m GPS accuracy horizontally, which is worse horizontally.
• Smartphones generally only have a 30-50m range for Wi-fi and Bluetooth which could cause potential problems if the UAV lost its signal – this would be less of a problem with site tour recording.

The six propellers of the HEXO+ make it the more stable of the two systems and more capable of landing if one motor were to fail.

HEXO+

The HEXO+ was a Kickstarter Project aimed at making aerial filming possible in many different areas without the need for another person controlling the UAV (Unmanned Aerial Vehicle) and camera. It is a hexocopter with six rotors designed to carry the GoPro camera on either a 2-axis gimbal or a 3-axis gimbal. It automatically flies itself and films the person holding the smartphone/tablet device which controls the UAV keeping them in frame as it flies.
http://hexoplus.com/

There is also an optional mount for another kickstarter project, the 360cam, which provides aerial 360° photos and videos.

The HEXO+ is controlled by an App on smartphones available in both iOS and Android versions. It can be set to film the person holding the smartphone from the front, side, back and anywhere in between, with the distance from the subject and altitude also being set. By using The Director’s Toolkit different filming scenarios can be configured, such as crane; pan, tilt, crab, dolly, 360° around you, far-to-close/close-to-far. Once configured the system can auto takeoff and land and will follow the subject maintaining the framing that was defined in the software. The system uses the Pixhawk autopilot system. It has a flight time of 15 minutes.

• Speed range: up to 70 kmh – 45mph
• Flight time of 15 min with gimbal attached
• Can fly in wind up to 15 mph
• iOS and Android apps

The system costs $949.00 with a 2-axis gimbal and $1,149.00 with a 3-axis gimbal.

Potential
Both the AirDog and similar system, the Hexo+, have the ability to follow a person carrying a smartphone or other device, keeping them in frame for the whole time frame of a video would seen to have great potential for the recording of site tours, which could now be recorded automatically from different altitudes showing the whole or parts of an excavation. The audio could be recorded with a digital recording device attached to the tour guide, with the audio and video being combined in post production.

They would also have the potential to record fieldwalking and exploration looking for new sites in remote regions.

The BBC has already begun to used UAV systems in the recording of news items – http://www.bbc.co.uk/news/business-24712136 – http://www.bbc.co.uk/blogs/researchanddevelopment/2012/04/collab-soton-uav.shtml – http://www.bbc.co.uk/programmes/n3csw972

Limitations
The HEXO+ is specifically designed for autonomous flight so it does not come with an RC (Radio Control) Controller, itthey can however both be switched to manual and an RC Controller bought separately can be used to control it like a standard UAV, although this obviously adds to the cost.

The recently released IRIS+ quadcopter has limited the usefulness of any UAV with “follow-me” technology, as not only is it a system with an RC controller and an autopilot that can be used to photographically map areas, but the system also has “follow-me” technology which matches that of other systems. It is also cheaper than the IRIS+.

The limitations of the system would be closely linked to the limitations of the GoPro camera which it uses to record.

The AirDog project rejected the use of smartphones for a number of reasons:

• Problems with using smartphones in extreme conditions – this is unlikely to be a problem.
• The average smartphone has only a 5-10m GPS accuracy horizontally, which is worse horizontally.
• Smartphones generally only have a 30-50m range for Wi-fi and Bluetooth which could cause potential problems if the UAV lost its signal – this would be less of a problem with site tour recording.

The six propellers of the HEXO+ make it the more stable of the two systems and more capable of landing if one motor were to fail although the extra motors will reduce the flight time.

Raspberry Pi Model B+

The Raspberry Pi Model B+ is the latest model in the Raspberry Pi stable of computers. It is a credit card sized computer that can run a number of operating systems including Linux and Android, it was originally aimed at teaching children computing, programming and electronics but has been embraced by a whole community of people interested in its potential.

With the GPIO (general purpose input/output) pins on the board many different electrical devices can be controlled; from turning an LED (light emitting diode) on and off to driving motors and taking readings from distance measuring devices. This makes it very useful for controlling robotics such as UAVs (Unmanned Aerial Vehicles) and Rovers.

By the inclusion of a battery pack it can be made completely portable, with the computer being controlled remotely via Wi-Fi using a wireless dongle and using either the SSH (Secure Shell) command prompt interface or the VNC (Virtual Network Computing) virtual desktop application, you can even use your mobile phone – http://www.raspberrypi.org/piui-control-your-pi-with-your-phone/.

The model B+ costs around £25.

Camera Module
Although the Raspberry Pi itself comes with no digital recording capabilities out of the box, for another £25 the camera module can be purchased and used to record video at 1080p30, 720p60 and VGA90 modes and images can be captured with its 5 megapixel camera.

Potential
The previous versions of the Raspberry Pi have already been used in robotics projects such as controlling Rovers and UAVs to controlling photographic recording stations. With extra GPIO pins and a more powerful computer this potential can be added to.
http://makezine.com/2013/07/06/the-raspberry-rover/

http://www.botched.co.uk/

It can be used to make cheaper versions of technology which already perform a usefully function; such as this gigapixel camera rig which takes overlapping DSLR photographs with preset motorised rotation and elevation of the rig set by the software on the Raspberry Pi, with the rotation being also controlled by the Raspberry Pi using a stepper motor whose rotation can be set accurately. The images can later be stitched together in software. A commercial version of this system is the GigaPan EPIC Pro gigapixel camera rig which costs $995. The software for the project is free to download. Free software solutions for stiching panorama photos together also exist, such as http://hugin.sourceforge.net/ and Microsoft’s ICE (Image Composite Editor) http://research.microsoft.com/en-us/um/redmond/groups/ivm/ICE/

An example gigapixel image using the rig can be seen here.

An example of a GigaPan capture undertaken with an EPIC Pro by the author and a colleague on the site of Netley Abbey in Hampshire as part of a recording project can be seen here.

Maker movement companies such have Adafruit have embraced the Raspberry Pi designing by building and selling many addons, including motor controller boards and touch screens.

Limiting factors
The Raspberry Pi can run many useful pieces of software but it is limited by it’s processing power, although multiple Pi’s could be used for different parts of a project.

360cam

The 360cam kickstarter project is a 360˚ Full HD camera, it is designed to take 360˚ horizontally and 300˚ vertically photographs and video with the systems 3 185˚ fisheye lens 8mpx cameras.
It provides images at a 4096 x 2048 resolution and video at 2046 x 1024 resolution at 30 fps h.264 mp4 and can record video for 60 minutes. The system can stitch images together in real time inside the camera, the files can also be exported to other 360˚ photo and video software. It also has the ability to stream Live video over WiFi.

During the recording process multiple images can be taken at different exposure levels providing high dynamic range photographs, which allows more variation in texture and colour to be recorded which can be used in the study of archaeology and cultural heritage.

The WiFi allows the 360cam to be controlled remotely with Android and iOS mobile phones and tablets.

http://www.360.tv/

One of the accessories for the 360cam is an underwater lens cup allowing 360˚ photographs and video to be taken underwater.

It can be easily attached to another kickstarter project, the HERO+ intelligent drone, with an optional mount for an additional $80.

With the 360cam Oculus Rift video player it is possible to view the immersive videos created using the Oculus Rift Virtual Reality headset.

The system costs $499.

Potential
The 360cam has great potential for the immersive recording of everything from archaeological excavations to walk-throughs of historic monuments. Its ability to be simply played in an Oculus Rift player adds significantly to the presentation possibilities of the video, although the current Oculus Rift Development Kit is another $350. The underwater lens cap allows the recording of photographs and video underwater adding potential for maritime archaeology.

Whether the overlap of the individual images can be used to create a photogrammetry model of the subject matter of the recording will have to be tested.

Limitations
The cameras of the 360cam are only 8mpx so the images provided would be of a much lower size than the similar Panono Camera.

Only a mount for the HERO+ drone can be purchased, but a mount for other UAVs could be printed using a 3D printer or manufactured in another way.

Google Cardboard

Google Cardboard are VR (Virtual Reality) goggles made out of cardboard using an android smart phone as the central processing unit and display via the Google Cardboard App. The cardboard shell can either be purchased for less than £10 complete with lenses and magnet button control or the cardboard design downloaded from the website and the other parts purchased separately.

The mobile phone provides you with orientation tracking using a gyroscope and accelerometer built into the phone which means that the the app can track the movement of the user’s head updating the imagery on the phone depending on the direction that the user is facing.

A magnetic trigger on the outside of the cardboard allows interaction with the VR environment by effecting the magnetometer in the phone. Although with calibrated magnetometers this can only act as a single button, with uncalibrated magnetometers incorporated in newer phone there is greater variety of abilities with the possibility of incorporating a joypad into the outside of the case.

The Google Camera App (On Android 4.4 and later) can record 360° Photo Spheres which can easily be viewed in the Google Cardboard App on the smartphone, other Photo Spheres can be viewed be editing their file names. The app can also view videos on YouTube including those designed for the Oculus Rift or other VR Gear with two separate views in the video. Integration with Google Earth and Google Maps Street View is also possible.

Two SDKs (Software Development Kits) can be downloaded from the website:

• The first is the Cardboard SDK for Android which allows VR applications to be quickly created in OpenGL.
• The second is the Cardboard SDK for Unity which allows an application created in the Unity 3D game engine to be viewed in the Google Cardboard Goggles or to design one from scratch.

Although designed for phones with the Android operating system, phones using iOS can also be used in the Google Cardboard using Durvois Dive (a plastic VR Goggle frame which also uses smartphones) apps.

Potential
Google Cardboard was designed to both allow the cheap and easy ability for almost anyone to view VR and to help push forward development of the systems.

It has the ability to both view virtual reconstructions of sites and view still 360° photographs and immersive videos of sites, these can easily be downloaded and viewed by anyone anywhere in the world using the technology. The fact that the phone can be used to create 360° Photo Spheres as well enables the both the recording and viewing of views of cultural heritage and excavations with technology that may already be owned.

Limitations
Because it uses a smartphone there are limitations to its abilities that would not be there with more powerful computer systems. The quality of the imagery is also completely dependent on the quality of the smartphone screen.

Although the control is limited to the one button on the outside of the Google Cardboard some wi-fi/bluetooth game controllers can be used with Android operating systems allowing much more interaction. There have however been problems with the button working, particularly on certain models, it is after-all a technical workaround to use a device for a function it was not designed for.