Jonathan T Wojack wrote: > Are the two images of Mir depicting the slain space station in the same > orientation (just curious) ? The orientation of the dots seem to be the > same in both images. Or is it the same image twice, with the one of the > left with enhanced contrast and brightness? Dear Jonathan, It is the same image twice. The good image on the left is the original, excellent image sent to me by Bob Citron. The worse looking one on the right is the same image with the brightness and contrast turned DOWN. I purposely degraded the image to demonstrate that on lesser quality original images (like mine, for example) parts of the station may not be visible, thereby potentially confusing attempts to positively identify the attitude of the station. Bob's image shows amazing detail, and is due largely to the extreme sophistication of his equipment and technique. If I had attempted and image at the same time and place with my basic equipment, I would have been very lucky to have acquired an image more like the one on the right, or perhaps just a blob of light, due to the complex appearance of the station in that particular position and lighting conditions. In my attempts to positively identify the attitude of Mir or ISS in my own images I aquired a couple of the plastic models of Mir, and even went so far as to construct a basic "tube and cylinder" 3-d model of Mir in Autocad 2000. I found that poor seeing conditions combined with the drastic effects of ever-changing conditions light and shadow on the station in various attitudes can easily cause large parts of the station to disappear, while others appear prominent. The photo on the right was adjusted by less than 20 percent, and notice how one of the solar arrays disappears completely. The remaining array could then easily be mistaken for the "boom" which would then cause the interpretation to be off by 90 degrees in two axis. The results of my studies indicate to me that capturing any satellite in a favorable lighting condition and attitude is potentially more important to the final image than the quality and sophistication of the imaging equipment, meaning that if one were to "get lucky" with a favorable pass one could acquire good images with very little equipment, and this has been demonstrated recently with some amazing photos taken with a webcam: http://www.djcash.demon.co.uk/astro/webcam/webcam.htm Notice how the favorable orientation makes the features of the station distinctly visible, and how if the station had been turned 90 degrees, it would have been reduced to a simple streak of light due to the fact that most of the features of the station are fixed in the same plane. -- Tom Troszak, tomtroszak.com Technology Asheville, NC, USA 35.601 N, -82.554 W mailto:tom@tomtroszak.com.com ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Mon Jun 25 2001 - 07:59:04 PDT