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                 ASTERIODAL OCCULTATION - REPORT FORM

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           	           EAON & IOTA-ES

               EUROPEAN ASTEROIDAL OCCULTATION NETWORK

    INTERNATIONAL OCCULTATION TIMING ASSOCIATION EUROPEAN SECTION

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1.DATE: 2006/04/20
  STAR: TYC 2417-00632-1u
  ASTEROID: (3641) Williams Bay

2.OBSERVER:
  	Name: Gerhard Dangl
	Phone: ++43-(0)2842-53908
	Address: AUSTRIA, A-3830, Nonndorf 12
	E-mail: gerhard@dangl.at

3.OBSERVING STATION:
	Nearest city: Waidhofen/Thaya
	Latitude: N 48 47 34.2 (WGS84)
	Longitude: E 15 13 56.9 (WGS84)
	Altitude: 562m
	Single/Multiple: Single

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4.TIMING OF EVENTS:
	Occultation recorded: NEGATIVE
	Type of event:
	"S"tart observation; "I"nterrupt-"s"tart; "D"isappearance;
	"B"link; "F"lash; "E"nd observation; "I"nterrupt-"e"nd;
	"R"eappearance; "O"ther (specify)
	
	Personal Equation Substracted: No
	Event Time (UT)		P.E. Accuracy + Comments
	code: HH:MM:SS.ss      S.ss  S.ss
	
	S:   20:36:35   

	E:   20:40:11   
	
5.TELESCOPE:
	Type: Newton
	Focal length: 1200mm
 	Aperture: 254 mm
	Magnification: --- (primary focus)
	Mount: Equatorial
	Motor drive: Yes

6.TIMING & RECORDING:
	Timekeeping: GPS 1PPS Garmin18 LVC + KIWI-OSD
        Sensor/Camera: 1/3" Sony EXview CCD-Sensor ICX255AL/Videomodul SK-1004X
	Mode of recording: PAL-Video, AVI, YUY2, Huffyuv, 50 fields per second
	Device of recording: USB2 Videograbber, Notebook Harddisk
        Time insertion: KIWI-OSD (50 fields per second)  

7.OBSERVING CONDITIONS:
	Atmospheric transparency: good
	Wind: 0-0.5m/s 
	Star image stability: fair
	Minor planet visible: No
	Temperature: 282 Kelvin (+09 deg Celsius)
	
8.ADDITIONAL COMMENTS:
        Target Elevation 29.5 deg

        Video evaluation in single fields possible (point of time +/-10ms)

        Only Clear glass filter (Astronomik) for CCD protection was used

        Limit on Video "live"-frames
        2UCAC 44810785 +11.4 mag permanently visible
        2UCAC 44810847 +11.7 mag on about 95% of frames visible

        Limit on 256 integrated frames (Registax + Photoshop)
        A2_1200_03892520 V Mag +14.1
        
        Position and timing
	Garmin GPS18 LVC
        Receiving 09 satellites
        Horizontal Dilution of Precision 1.0
        Geoidal separation 44.4m

        Gerhard Dangl
	gerhard@dangl.at
	www.dangl.at/
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