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AO-40 Orbit 216 Pictures



Hi All,

Many thanks to all the many stations who captured (and sent in telemetry)
from AO-40 on orbits 216 and 217!!!

We were able to complete the entire D-block dataset. The images have now
been extracted, and analyzed.

The images can be found in the 216.zip file included in the archive zip file
ao40_2001-04-21_00217.zip file in the directory:
http://www.amsat.org/amsat/ftp/telemetry/ao40/2001/04/

Attached below are some notes from James Miller, G3RUH about the picture
test:

Thanks Again!!!

Paul, VP9MU
AO-40 Telemetry Archive

--------------

Camera Pictures Orbit 216 MA 246
--------------------------------
Eleven pictures were taken.  The JPEG quality was Q=25 in order to keep the
file
size small, and the same Q as was used for Earth images pre-incident.  The
JPEGs are 256 greyscale.

The IHU-2 clock was checked and found to be correct within a few seconds.

Based on the latest keplerian elements, conditions were:

                         2001 Apr 20   Rev 216
  Image     Filename        utc          MA
  ---------------------------------------------------------
   P1      152126.JPG      1521:26
   P2      152324.JPG      1523:26
   P3      152523.JPG      1525:26
   P4      152721.JPG      1527:26
   P5      152919.JPG      1529:26    248.01
   P6      153118.JPG      1531:26    248.47
   P7      153316.JPG      1533:26    248.92
   P8      153515.JPG      1535:26    249.34
   P9      153713.JPG      1537:26
   P10     153911.JPG      1539:26
   P11     154110.JPG      1541:26
  ---------------------------------------------------------

Spin rate is 2.047 rpm


Comments
--------
1. The spacecraft spins some 14 deg during the exposure; distortion is
   minor.

2. Three circular aberrations (like a crater) are observed; two at the top
   and one at the bottom.  Image P7 is interesting in this context.

3. The Earth's edge is in several of these images, and the angular distance
   from the bore-sight indicates an attitude of alon/alat = 106/11 with
   pin-point convergence.

4. This estimate agrees with the Earth sensors' last triggers at  1134:23
   (lower) and 1324:34 (upper) within 1°.

5. 1533.GIF shows AO-40's view of the Earth when image P7 was taken.  The
   square corresponds to the image, and the land mass is North America.
Lines
   of latitude and longitude are at 15° intervals.

6. The quality of these images is vastly worse than those taken in similar
   circumstances prior to the 200 Dec 13 incident.  The dynamic range is
   reduced, black is no longer black (e.g. P2-4) and there are at least
three
   "blobs" apparent.  Despite this, the navigation data from the camera
remains
   excellent.


jrm
2001 Apr 21 [Sat] 1200 utc




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