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Single positive chord events give ambiguous results.

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Presentation on theme: "Single positive chord events give ambiguous results."— Presentation transcript:



3 Single positive chord events give ambiguous results

4 Here, a single chord with a miss improves results slightly

5 Two well placed positives give shape and astrometry information

6 22 chords tell the whole story!

7 My portable setup to remotely observe the lunar grazing occultation of Regulus on November 3, 2007. Toooooo much stuff! Thus began the quest to miniaturize…

8 Separation should be many km, much larger than for grazes, so tracking times & errors are too large Unguided is possible since the prediction times are accurate enough, to less that 1 min. = ¼ Point telescope beforehand to same altitude and azimuth that the target star will have at event time and keep it fixed in that direction Bill Gray recently added a feature to Guide 8 that will produce a finder chart with the time of an Alt-Azimuth position as a trail across the sky. Can usually find guide stars that are easier to find than the target Find a safe but accessible place for both the attended & remote scopes Separation distance limited by travel time & total tape record time 75mm (focal length) f/1.8 C-mount lens (42mm aperture) Orion 9x50 right angle finder modified to be a video scope. (50mm aperture f/4) The picture seen round the World. I sent this shot of a single video field of the Pleiades out on December 6 th, 2007 showing that our sensitive PC164C cameras with a simple 75mm f/1.8 C-mount camera lens (42mm aperture) could see to almost 10 th magnitude.

9 My Galileo sized optics official observation report!


11 My answer to Paul Maleys 6 pack challenge! Scotty Degenhardts 6 pack + 1 remote occultation system


13 50mm objective, f/2 effective f/ratio (with Owl focal reducer)



16 Mighty Mini optics (half of a Tasco Essentials 10x50 binocular) PC164CEX-2 video camera MX-350 miniature tripod (collapses to 12) Canon ZR camcorder (digital VCR) 9 AA NiMH battery pack Prime focus adapter for lunar occultations Total weight: under 10 lbs Limiting magnitude = 10.2 FOV = 3.2 x 2.4 degrees (using Owl FR) System designed by Scott Degenhardt

17 (Scottys Mighty Mini deployment statistics)




21 One name for me would be: MINIMALIST

22 IM LAZY!!!

23 1.Never ever ever ever go straight to the target star, ALWAYS prepoint! 9 times out of 10 the target star is faint and/or located in an awkward star hopping point in the sky. Prepointing allows you to pick the most convenient time to aim the scope AND to pick the brightest star near the most recognizable asterism (saves an INCREDIBLE amount of time, blood, sweat, tears, hair follicles, adds years to you life, takes years off your wife…. Yada yada you get the picture). And starting at the target star means that you HAVE to stay on the target star, i.e. your polar aligning better be good (lotsa deployment time there), your motor drive better not have errors (lotsa $ there), and your batteries better last, even in the cold… (lotsa prayers there)! Prepointing uses THE most accurate drive available to man… the Earths rotation. LiMovie reduction with a prepointed target star drifting through at a steady rate is a BREEZE to accomplish using the Drift Tracking Method. Use the widest FOV (field of view) instrument you have to attain the magnitude depth needed. I have found statistically that doubling the FOV decreases prepoint time not by half, but by a quarter of the time! WHAT DONT I NEED!! While those techno gadgets seem like a good idea for a successful observing run, they are a huge strain on your time budget. KISS works in this arena. Holding a flashlight takes up one of my hands, roughly doubling the time needed to accomplish a task. I wear a headlight to free up both hands, and it also is always shining where my eyes are pointed. Basic parts that I need: a video camera, a battery pack for the camera, a recording device (Canon ZR Models ZR10 through ZR300 work), an optical instrument with dew shield, the smallest tripod available for the optical instrument, a time keeping device (KIWI), charts & maps. Thats it. (I will concede here that I do use a GPS to navigate to/from sites, reduces time) How small and how light you can go with these determine how many stations you can carry/deploy. KISS

24 Devicesms accuracies$ms$ tape recorder, SW radio300$70.0021000 TV/VCR, SW radio100$150.0015000 TV/VCR, KIWI16.6$250.004150 miniDV16.6$37.60624 laptop29.1$600.0017460 laptop, KIWI16.6$750.0012450 DVR29.1$300.008730 MDVR?$300.00#VALUE!


26 PC164C voltage specs = 12VDC +/- 10% (i.e. 13.2 to 10.8VDC)



29 Get your spoon out!

30 Kecks adaptive optics image of Kleopatra (discovering 2 new moons, arrowed) Asteroid distance = 1.2AU Resolution = 0.035 = ~30km at asteroid Occultation Parameters: Resolution of an occultation timing of (216) Kleopatra on Sep 28 th, 2008: Shadow speed = 9km/s Camera field rate = 59.94 fps Resolution = 150 meters/field Occultation timing is 200 times the resolution of Kecks adaptive optics!

31 FROM THIS…..TO….THIS!!! Galileo would be PROUD! CONCLUSION: The miniaturization of optics for occultation timings has increased the number of extra stations per event, the frequency that extra stations are deployed, and more importantly, the total number of observations! Statistically this means the number of positive measurements will increase, as will our knowledge of these rocks.

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