It's one of the few great archaeological mysteries of the world, and now a bunch of gadget-wielding geeks are going to try and solve it.

The tomb of Genghis Khan, founder of the Mongol empire and one of the world's greatest and most ruthless emperors, has remained hidden for nearly eight centuries. According to legend, Khan died in 1227 near the Liupan mountains of China and is thought to be buried in the northeastern region of what is currently Mongolia.

Now a group of researchers led by University of California San Diego's Center of Interdisciplinary Science for Art, Architecture and Archaeology, with funding from National Geographic, have embarked on a quest to find this ancient grave. Their secret weapon: an array of technological gizmos ranging from unmanned aerial vehicles to sophisticated satellites and 3-D displays.

"This is a first of its kind,” says Mike Henning, a researcher at UCSD, “a large scale expeditionary-type project that promises to open up new doors for technology."

Hennig and the entire expeditionary team left for Mongolia earlier in July and will be there until the end of the month. They will do most of their work in an 11-square mile region in Mongolia flying two UAVs, directing satellite imagery and collecting data that will be processed at home later.

GeoEye

Satellite imagery will play a key role in the search for the tomb. GeoEye, a company that offers geospatial data from high-resolution cameras on board its orbiting satellites, will work with the researchers. Based on their instructions, GeoEye will point its Ikonos satellite at regions where Khan's grave is likely to be. The resultant imagery will be downloaded from Ikonos via a microwave downlink and processed at GeoEye's office in Denver.

"Kids in MIT are using our satellite imagery to study urban planning in Mexico City," says Matt O'Connell, CEO of Geo-Eye. "Georgia Tech is working to track gorilla habitats and now we hope our satellite can help find the tomb of Genghis Khan."

GeoEye's Ikonos satellite launched about 10 years ago. Ikonos orbits the earth every 90 minutes and can create color images with a resolution of up to 1 meter. The satellite is 423 miles up in the sky.

"With the Ikonos images we can see something the size of 32 inches on the ground," says O'Connell.

Currently, GeoEye has three satellites in orbit: the Ikonos, GeoEye1 and OrbView 2. GeoEye's customers include governments and businesses. For instance, pictures from GeoEye1 satellite are used in Google Maps and Google Earth.

In tests earlier, the average GeoEye image given to the UCSD project members covered about 6.8 square miles and was about 300 MB in size.

"They can apply data mining algorithms to our imagery and scan for anomalies such as unnatural geometric formations," says O'Connell. "It's the first step in their quest."

Above: A one-meter resolution image of the Zipingpu Dam in the Sichuan Province of China taken by GeoEye’s Ikonos satellite, a few months before the dam was damaged in a massive earthquake in 2007. Credit: GeoEye



UAVs

Researchers in Mongolia will also be counting on unmanned aerial vehicles to get pictures of the zones that they believe could hold the grave.

"We are looking at a GPS-guided aircraft that can do live streaming and digital still images at the same time," says Gene Robinson, CEO of RP Flight Systems, whose two UAVs will be deployed for the task. "Its capabilities are pretty impressive." The Texas-based company has been designing and selling UAVs used in search, rescue and recovery missions for about seven years.

Each UAV has a 4-foot wing span and weighs around 4 pounds, including all the equipment. The UAVs are made with a composite based on polystyrene and fiber glass and the hull is coated with Kevlar. The UAVs, powered by a lithium-polymer battery, will fly at a typical altitude of between 400 and 600 feet with each flight lasting about an hour.

The UAVs are standard off-the-shelf systems called the Spectra Flying Wing. The only customization is a modified camera that can do both infrared and full color images, says Robinson. Each of the fully autonomous UAVs with sensors costs $15,000.

The biggest draw of RP's UAVs is that they are unclassified, allowing the images from them to be easily accessed by all. Aerial vehicles from NASA or most governmental agencies are classified as ‘dual-use technology,’ marking them suitable for military and civilian use. But it also limits how the technology or information derived from it can be used. "If a dual-use airplane takes pictures, those are considered classified and have to be declassified before anyone can take a look at it," says Robinson, a process that could sometime take days. "With us the data is available for immediate distribution."

Downloading the images from the UAV to a computer is as simple as unplugging the on-board SD card and hooking it up to a PC. "The image analysis involves looking at patterns, colors, shapes that don't belong in nature," says Robinson.

Above: A Spectra unmanned air vehicle similar to the one that will be used in Mongolia Credit: RP Flight Systems

Creating a computational algorithm

Earlier this year, Luke Barrington, a doctoral student at UCSD, released a Facebook application called 'Herd It' that allows users to discover music, much like Pandora or Last.fm. The app also lets listeners play word association games based on the music they hear and identify the key themes in the song.

The idea was to create a machine learning algorithm that could analyze and classify music. Think of it as similar to what Pandora does—the difference being that the Herd It uses people to train the algorithm instead of having people always classify the music.

"One of the key components in learning systems is that you need to train them with a couple of strong examples," says Barrington. "So with Herd It, I developed this game that would collect consensus about what genre a song belongs to."

The crowdsourcing collects reliable, accurate examples of words people use to describe music, which can be used as training data for a machine learning system. The system can then listen and analyze songs and describe them the same way that people do.

Turns out that's exactly the kind of approach that the Genghis Khan expedition needs, which is why Barrington is turning his talents from pop music to image analysis. With hundreds of satellite images to sift through, the team hopes to use people to find examples of unnatural features.

"One of the challenges with the satellite imagery is that we don't know what exactly we are looking for," says Barrington. "We need human input to find examples of anomalies and unnatural patterns that can be used to train an algorithm."

It's also a way to give the larger community a chance to play Indiana Jones. "We want to help people become a bit of explorers themselves," says Barrington.

Above: The Herd It application created by Luke Barrington allows participants to rate songs and help the algorithm teach how to identify different kinds of music. A similar program is likely to be created to help classify features seen in satellite imagery from Mongolia. Credit: Luke Barrington

HIPerSpace

Picture a massive wall of displays that has the world's highest resolution and can be used to look through aerial photos of the Mongolian region whose secrets are yet to be revealed. UCSD's HIPerSpace or the Highly Interactive Parallelized Display Space can do just that.

HIPerSpace was first deployed in 2006 as an ultra-high resolution distributed display system. The system allows researchers to get a sweeping view of their images while still being able to see the smallest details.

"We hope to take the input people provide us on the satellite images and display it on this wall in almost real time," says Barrington. Geo-Eye offers the satellite imagery on CDs to scientists for further research.

HIPerSpace has 70 tiles with a display resolution of 35,840 x 8,000 pixels or 286,720,000 pixels total. The wall uses 30-inch Dell LCD screens. And to process the graphics, the system has 80 NVIDIA Quadro FX 5600 graphics processing units. Together that puts the theoretical computational capability of the entire system at 40 teraflops.

Above: This image is a mosaic of the Carina Nebula, assembled from 48 frames taken with the Hubble Space Telescope's Advanced Camera for Surveys. It shows the birth of a new star. Credit: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA)

StarCave

If the world's biggest wall of displays isn't enough, then it's time to step into the StarCAVE – a five-sided virtual reality room where scientific models can be projected on a 360-degree screen surrounding the viewer.

Viewers use 3D polarizing glasses to watch the images in front, behind or even below them. They can even navigate virtually through a building.

When StarCAVE was opened in 2008, the room had a combined resolution of over 68 million pixels distributed over 15 rear-projected walls and two floor screens. The pentagon-shaped room has three stacked screens on each wall, with the bottom and top screens titled inward by 15 degrees to increase the feeling of immersion, say UCSD researchers.

"You can stand inside the StarCAVE and all these screens will project in 3-D, so you almost get the feeling you are flying through the area you are looking at," says Barrington.

The StarCAVE uses 34 Nvidia processors to generate to generate the images. Add to that 34 high-definition projectors to create bright left and right eye visuals that combine to form the ultimate 3-D image. Each pair of projectors is powered by a quad-core PC running on Linux, with dual graphics processing units and dual network cards to achieve at least 10 gigabit Ethernet networking.

Above: Tom DeFanti in the StarCAVE Credit: UCSD/Flickr

Will all this technological ammunition, can Genghis Khan's tomb still remain hidden? It is possible, says Hennig. "I would like to go in and think that we would be the ones to find it but there are so many variables," he says. "Cultures go great lengths to hide the things they want to."

Legend has it Khan's grave is unmarked and a river was diverted over it to make it difficult to find. Over the centuries it has been a 'forbidden zone.' It makes the search for the tomb a challenge worthy of our technological prowess.

"Even if we come back and don't find anything, just being to go there and demonstrate what we can do today with our system is worth it," says Hennig.

If UCSD researchers can with some certainty point to a location where they believe Khan and his family lie buried, it will be up to the Mongolian government do initiate the process of an archaeological excavation.

It's now a battle between a wily warrior whose secrets have remained safe for nearly eight centuries and a community of geeks who are determined to unravel it.

Image: Thomas A. Lessman