http://vvv.com/interface/interact.html (PC Press Internet CD, 03/1996)
PCI specializes in remote sensing software development. What is remote sensing? Look up.... waaay up! There are satellites orbiting the Earth as we speak, continuously collecting data and transmitting it back to Earth. PCI develops software which takes this raw satellite data and converts it into useable form. You may be surprised how much they can learn about the Earth from way up yonder, but even more surprised how well they can -see- what they are looking at. We met with Clay Atcheson, PCI's Branch Manager and asked him to explain remote sensing.
A: Remote sensing is the acquisition of information in a digital format, recorded by satellite or aircraft, which determines the condition of the world at the time of the acquisition.
InterFace: Are they photos?
A: Some are, but most remote sensing data is digital information. It makes it easier to use it on computers.
InterFace: What does PCI do?
A: PCI is a developer of software for processing remotely sensed data. The company is about 15 years old and is the biggest of its kind in Canada and second biggest in the world. We started out making software on big mainframe computers, then stepped down to the PC level when they became available. Now our products are available for the entire range of computer platforms and operating systems. IBM, UNIX, SUN, KUBOTA , MAC, you name it, we got it.
InterFace: What does your software do?
A: The software is designed to take raw satellite data and process it through filters (classification processes) allowing modifications for geometry, required accuracy, mapping, an entire variety of variables. It also allows vectors to be placed on top of the raster (data) files. Vectors being defined as; roadways or waterways or forestry areas or whatever you wish to visualize or analyse. Anything that is linear in nature can be added onto the raster-layer to provide more information about the source data.
InterFace: Where do your customers get the satellite data in the first place?
A: Data sources are available here in Canada from RadarSat International. They can also purchase data from European or American sources.
InterFace: Once the customer has the data and your software, depending on the parameters of what they are looking for they can begin to analyse things?
A: That's right.
InterFace: How does the software derive from the data, which part is an image?
A: The software doesn't derive it from the data as such. The individual operating the software has to determine what they want to learn from the data. All of the users of the data be it, agriculturalists, geologists, biologists, foresters, all take the same basic information and approach it in different ways. Our software is designed to give each of these types of groups the tools they need in order to process the data and extract the certain types of information they need to know. For example, a forester may want to know about the distribution of a certain tree species. Each tree species has its own wavelength of reflected energy. The forester will then key in on those certain digital values for that reflected energy. He/she will then be able to ascertain things such as whether or not the tree is healthy; if there is a low chlorophyll content or that the tree is not rooted properly; storm damaged or whatever. All of this from the different digital values of reflected energy. You can get really specific about what you are looking for!
InterFace: Healthy trees would really look a lot different from unhealthy ones?
A: Absolutely.
InterFace: You could actually pick out an apple tree from a pear tree?
A: Which variety of apple would you like?
InterFace: That's amazing, considering the data originates from outer space.
A: I guess for the uninitiated it could be a bit overwhelming? When you work with the software long enough you tend to take satellite data for granted.
InterFace: Is it by analysing the different colors of the spectrum or by various frequencies that you make these kind of determinations?
A: It is not colors as such. We assign the colors to the digital values. It can be any color you like. Trees don't have to be green. It is not colors that we are really looking for. What the computer operator does is tell the computer "Every time you see a pixel of this frequency tell me where it is." That way they can identify anything they want.
InterFace: I guess what I am trying to get straight here is what frequencies you are talking about? Electromagnetic?
A: Primarily reflected light.
InterFace: OK. Let's see if I understand this properly. It is the differences in the light frequencies which allows you to differentiate; via the data, the various qualities of the subject matter. Is that correct?
A: (grinning) That's right!
InterFace: How many frequencies does light have?
A: Millions!
InterFace: What other types of analysis could you do with the software?
A: Lots. The software also allows you to take two pictures that overlap- (I'm talking about pictures from space here, from the top down) From these two pictures we can derive a digital elevation model which interprets elevations from each of the picture elements (pixels) in the image. X equals the horizontal value and Y equals the vertical value. This is information we already have from the images. The software then extracts the Z value which is elevation value. Now you have a "straight on" view of what you are looking at. By processing the data "on-the-fly" you can actually fly over the area covered by the data. You can also raise or lower the angle of elevation so you can fly or view the area from different heights. In other words we can generate a 3D perspective view. It's exactly the same as piloting an airplane, except that you never leave your desk!
InterFace: Who are the main clients for this type of technology? Who utilizes it?
A: Any number of groups, from geologists for mining purposes, forestry companies, Ocean Sciences. Government is a major user of remotely sensed data. Coming from a general consumer point of view, the education sector is becoming much more prevalent. It's not only used by the big companies. We are starting to see smaller businesses come on-board.
InterFace: Would you give me some other examples of where this technology would be beneficial?
A: Sure. Water and flood control. You could watch rising water levels and know in advance which areas were in danger. They used it last year for the big floods in the States. The Mississippi and Missouri rivers. The RadarSat images allowed them to watch the progress of the flood and more importantly calculate the rate at which the water was rising and predict where the flood plains would be. (change potential) This gave everyone a chance to evacuate, well in advance.
InterFace: What does the future hold for remote sensing? What can we expect to see next?
A: Even more discriminating criteria.
InterFace: Such as........
A: Neural Networks. These are very complex. You are training the computer to look at a number of variations, all at the same time, as compared to the standard classifications available through various software products now on the market. NeuralNet is a real buzzword. Basically it means working more closely with the computer. Teaching it and training it, developing forms of Artificial Intelligence.
ED. NOTE: Has anyone seen Commander Data?
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