Japanese researchers have gone high-tech in an effort to unravel the mysteries behind the construction of Egypt’s pyramids, mapping out the gigantic structures using advanced laser scanners and a drone.

In March, in Abusir in the suburbs of Cairo, the group led by archaeologist Yukinori Kawae from Nagoya University set up more than 10 scanners around a pyramid. It then peppered the structure several hundred thousand times per second with laser beams to precisely measure the locations and shapes of each stone in the building to create an extremely detailed three-dimensional image. The group worked jointly with the Czech Institute of Egyptology.

In February, Kawae’s group also worked with TV Man Union Inc., a Tokyo-based production company, to use a drone to take digital photos from various angles of the Great Pyramid of Giza as part of efforts to create detailed survey maps of the structure.

“Discussions about pyramid construction can be likened to a crime investigation with scant evidence and insufficient on-site inspection,” said Kawae.

In traditional theories, the weights of each stone used to build the Great Pyramid are believed to be similar, but a recent finding suggests they may range from 300 kg to 60 tons.

According to Kawae, the research team finished measuring a total of seven pyramids and will process the imagery it collected to create more accurate survey maps.

Kawae said he believes the construction methods may differ among pyramids and hopes that by comparing detailed survey maps, researchers will move closer to solving the mysteries behind the ancient Egyptian buildings.

The pyramid built for Pharaoh Khufu, estimated to be 147 meters high at the time of construction, was too large to be measured accurately and there were no survey maps showing the structure in detail, including the sizes of each stone. Up to 3 million stones are believed to have been used to complete it.

There have been various theories on how ancient people built the pyramids, with some researchers saying workers elevated stones into place by sliding them up straight ramps and others maintaining that the building materials were dragged to their final locations on ramps that wound around all sides of a pyramid.

The team plans to gather data that can be the basis for future academic study and reveal how the pyramids were built in a scientific way, Kawae said.