Submitted by scott on Thu, 11/24/2011 - 14:07

I joined up with Google+ a few months ago but have yet to do very much with it. One thing I have found is the photographic work of Trey Ratcliff, https://plus.google.com/photos/105237212888595777019/albums/56230424904…

I was at first a bit amazed at how what he did appeared much like things I'd seen during strange moments in the '70's as well as the clarity I experienced while backbacking in the High Sierras, I mean the alpine regions of the High Sierras. I wondered at how he did it. A little investigation revealed that he uses a technique referred to as HDR or High Dynamic Range. Essentially this involves multiple images of the same scene at differing aperture settings. By combining these images into a single image, along with a large bag of other tricks, he produces visions as if from an enhanced state of consciousness.

I was thinking about this process and recalled that it is very similar to what I was doing back in the days of being a professional cartographer for the US Army Corps of Engineers as well as in an aborted business attempt using an image processing computer system built on a CP/M computer system. I would acquire black and white aerial photographs, which contain the full spectral range of visible light, then create separate images (grey scale files) filtered through colored filters; blue, green, and red. I then enhanced the grey scales of each image and recombined them into a single image. This results in what is referred to as a false color composite. We did the same thing with images from band widths outside the visible spectrum, most commonly the infra-red range. Such images are very useful for land cover and land use analysis.

That old CP/M computer didn't have a hard drive. It had two floppy drives, the kind of floppy with paper sleeves. The EROS data center had developed what was then considered a portable system called RIPS. If I remember correctly there was a computer, with the two drives; a green screen monitor, for keyboard input; and a color monitor for viewing the images. It had a b/w video camera and a collection of color filters and a color printer, the kind with a ribbon. I also took pictures of the color monitor with an SLR camera on a tripod.

I tried very hard to make that business work but was cut short by partners going sideways. I haven't been a geographer since then and I do miss it. GIS has come a long ways since those days. Most data crunching was done on main frames, I mean real main frames, the kind pronounced "Burroughs". At one time I even entertained the fantasy of digitizing the Columbia River, from the mouth to John Day and creating an interactive video complete with zooms and associated text. Now, we have Google Earth, and most business attempts fail anyway.