Holo cartography from Turkish military.
Most innovations in holography have been led by a holographer, whether in academic or commercial R&D, either because they see a function that holography can perform better than alternative techniques or they believe they can improve holograms in a particular way. But the Turkish General Command of Mapping (GCM), working with MTM Holografi, has turned this practice on its head by investigating the application of holography to mapping, in what it has termed Holo-cartography. A team led by H.Polat Dalkiran has produced holograms which show the terrain of the mapped area in 3D, which they refer to as 'opening our vision to a new area of cartography.' The others working on this were Servet Ozagac, also of GCM, and Hakan Buyukbayrak of MTM Holography.
HoloMap from the Cartographers
Dalkiran acknowledges the work of Zebra Imaging in pioneering the creation of holographic maps (although the first work in this field was done in Canada using holographic stereograms), but the Mapping Command has approached the challenge from their own perspective as cartographers. Their objective is to make it easier to visualise a landscape from a map while still retaining all the symbolic data that is on a typical 2D map.
They have coined the terms digital carto-hologram (DCH) and digital holographic relief map (D-HRM) for their work, as they have taken the surveyed cartographic vector data to create topographic maps portrayed holographically. They identify several principles of holo-cartography which are required to establish a holo-map as an effective substitute for a standard contour map in military or other application; it is not enough for it to reveal the terrain in 3D, it also needs to carry data such as grid lines, borders, textual information such as place names, and so on. This is what Dalkiran and his team set out to do.
GCM has been producing digital topographic line maps using a custom-designed system called Karto25, so this was the system used to create the digital image for the holomap. They restricted the content to basic features such as roads and railways, buildings, borders, bridges and waterways, and converted these to a 3D symbol library using Lightwave[R] software to create 3D symbols for modelling and colouring, although they point out that more sophisticated software is needed to deliver the capability of the hologram. They separately drew up a terrain model of the selected area with an exaggerated vertical scale, converting this to AutoCAD's DXF format. This and the 3D symbols were loaded to Autodesk's 3DS Max[R] software, and textured from an aerial photograph of the area.
This file of different overlaid graphics was then rendered to create the full 3D image for the hologram exposure, which took over 24 hours. This 3D image was then exposed on to silver halide holographic film using a Holoprinter, which took six hours to produce a 50 x 40 cm hologram at 5000 lines/mm. The result is shown in the photo above.