Time for three-dimensional maps

(From Framsyn Magazine 5, 2006)

The Swedish Defence Research Agency (FOI) has already constructed a three-dimensional image of an urban environment allowing urban warfare operations to be simulated. Now the scientists are aiming to produce three-dimensional maps using the same technology.

Send in an unmanned aerial vehicle, a so-called UAV, and back comes a map. High definition. In a couple of minutes.
“At any rate, this can be something to aim for,” says Ulf Söderman who works with laser systems at FOI.

“Maybe we will never quite get there but that is the direction we are heading in.”

Ulf Söderman has worked extensively on laser radar. Norrköping has been scanned from the air and the results have been turned into a three-dimensional image.

“One might call it a kind of map, but it is one designed for simulation purposes. Military units must be able to use the model for exercise and combat simulation. Making maps for use in a real environment is another matter altogether. In those circumstances it would hardly be possible to cruise around in peace and quiet over the area in question. And the map would probably be needed in hours rather than weeks. No such operational requirements have been placed on us scientists or on our sensors. But that is now about to change.

Reconnaissance calls for sensors of different kinds. Usually the object of interest is a military target. In order to find the tank concealed in the woods, the signal processing experts have been working on ways to remove the woods digitally. Over 90 percent of the sensor information is discarded because it has contained terrain data.

“Now it is a question of information that we want to make use of,” says Ulf Söderman. “This means answering a range of research questions. Can the same sensors be used both for target location and for mapping? Can we use the same sorts of sensors that we use today? How can the sensors be used? How can we process the information? There are many such questions which determine the areas in which we need to conduct research.

Geoinfo from sensor data
Making a map today is based on photographs, often from satellites. For the future, studies are focusing on lasers, radar, IR, multi-wavelength cameras and so on.

The Swedish Defence Research Agency (FOI) is a leading authority on laser radar and has developed methods for building three-dimensional models. Framsyn has managed to catch Ulf Söderman by telephone while attending a conference in London and on his way to the next one in Paris.

“I would emphasise that we must increase the use of sensors, such as satellites for example, to obtain geographical and other relevant data for mapping and other purposes. This will assume increasing importance in the context of future information superiority, advanced information fusion and the generation of a common situation picture. The latter require geographical information as a basic input. We are also beginning to make use of the concept of geospatial intelligence which overlaps with what we have started to call tactical mapping. How we gather data, convert it into information which can be fed into the command and control system in support of data fusion and the presentation of a situation picture. The concept of geospatial information has been adopted in order to show that the situation picture is more than a map.

Land and sea data combined
In our vision of the future the sensors are mounted in an unmanned vehicle. To start with we have to be content with a human being. A person stands on a street corner and photographs the house, also giving the correct position of the object by means of GPS.

Ulf Söderman has made a study of an area of beach at Kapellskär in Stockholm’s northern archipelago.

“We have looked at whether one can fusion land and sea data. Two different systems have been. Hawkeye, which measures the depth of the sea water and Topeye which measures the topography of the land. Hawkeye uses a green laser and was developed right from the start by FOI. The results showed that it was possible to combine information from the two systems. Using a computer model one can move over land and sea and explore the underwater world. The level of the sea surface can be set arbitrarily,” Ulf Söderman tells us, and continues:

“The method could prove useful in civil applications, for example in studying the consequences of flooding in a river valley. It is possible to model the dynamics of the flooding and the flow rate of the flood water. The Swedish Meteorological and Hydrological Institute (SMHI) produces such models but the normal Green maps are not sufficiently detailed.