PW1000 OBSERVATORY TELESCOPE: 1000mm APERTURE CDK OPTICAL TUBE, F/6, ZERO EXPANSION LIGHT-WEIGHTED FUSED SILICA PRIMARY, SECONDARY AND TERTIARY MIRRORS, INCLUDES AUTOMATED DUAL NASMYTH FOCUS, RIGID ALT/AZ SPACE FRAME FORK, DIRECT DRIVE RADIAL TORQUE MOTORS, HIGH RESOLUTION ABSOLUTE ENCODERS DIRECTLY COUPLED TO EACH AXIS, FIELD DE-ROTATOR DRIVEN BY A DIRECT DRIVE TORQUE MOTOR COUPLED TO AN ABSOLUTE ENCODER AND MOTORIZED FOCUSER ON ONE NASMYTH PORT, VISUAL ADAPTER AND FEATHERTOUCH MANUAL FOCUSER ON THE SECOND NASMYTH PORT, PARKER INDUSTRIAL MOTOR CONTROL AND BUILT IN ELECTRONICS FOCUSING PACKAGE, PWI CONTROL SOFTWARE CONTROLS THE MOUNT, FOCUSER, ROTATING TERTIARY AND IS INTEGRATED WITH POINTXP MOUNT MODELING SOFTWARE. OPTICAL TUBE ALSO INCLUDES TWO FAN GROUPS, ONE SET BEHIND THE PRIMARY AND ONE SET IN FRONT OF THE FACE OF THE PRIMARY MIRROR. INCLUDES DEW HEATERS AND TEMPERATURE SENSORS FOR ALL MIRRORS. SYSTEM ALSO INCLUDES AUTOMATED PRIMARY MIRROR COVERS.
The PW1000 is a complete 1-meter observatory-class telescope featuring a direct drive altitude-azimuth (Alt-Az) mounting system designed and engineered by PlaneWave. With a diffraction-limited 100mm image circle, the PW1000 is designed to excel at imaging on the largest format CCD cameras available today. Light-weighted optics are made of zero expansion fused silica materials for excellent thermal stability and maximum throughput. The dual Nasmyth ports allow two instruments to be installed simultaneously, and a computer-controlled M3 mirror allows either instrument to be remotely selected in seconds. With direct-drive motors, high-resolution encoders, zero-backlash and no periodic error, the PW1000 sets a new standard in 1-meter class observatory telescopes.
Alt-Az mounts are the choice for most modern professional observatories. An Alt-Az mount is inherently more stable than an equatorial mount since there is no cantilevered mass, nor are there any large protruding counterweights to create a dangerous hazard in a public observatory. An Alt-Az telescope is also considerably more compact than its equatorial counterpart, allowing a larger telescope to fit in a smaller enclosure. The mass required to make a rigid Alt-Az mount is substantially less, leading to substantial cost savings. Unlike German Equatorial mounts, there are no meridian flips to deal with; you can image continuously from horizon to horizon if desired. With no polar alignment required, the Alt-Az mount is far more intuitive to use than a German Equatorial mount.
LIGHT-WEIGHTED FUSED SILICA OPTICS
Fused Silica has a coefficient of thermal expansion six times lower than Borosilicate (Pyrex) glass, which means that as it cools down, fused silica preserves its shape to a high degree of accuracy. This translates into consistent optical performance and unchanging focus over temperature changes.
DUAL NASMYTH FOCUS PORTS
The Nasmyth focus is along the altitude axis so the telescope does not need to be re-balanced when changing equipment. Eyepieces remain at a constant height, greatly simplifying access to the telescope for public observatories.
The computer-controlled M3 mirror allows either Nasmyth port to be selected in just a few seconds, allowing observers to easily transition between imaging and visual use, or other instrumentation.
ROTATING TERTIARY MIRROR
The PW1000 includes an integrated rotator for the tertiary mirror, with magnetic locks to position the mirror precisely at either Nasmyth focus position. The rotator can move from one port to the other in under 10 seconds.
DIRECT DRIVE MOTORS AND ENCODERS
Direct Drive motors and absolute on-axis encoders eliminate the need for reduction gears, thereby eliminating backlash and periodic error. With high-resolution encoders providing the feedback for the direct drive motors, not only will the telescope track without periodic error and backlash, the mount will also counter wind gusts with precise servo feedback. The direct drive motors can move the telescope at incredible speeds for tracking satellites or just to minimize target acquisition time.
AUTOMATED PRIMARY MIRROR SHUTTER
Protects the primary mirror from unwanted dust and moisture with this integrated four shutter automated system, fully controllable with PlaneWave’s PWI software.
The PW1000 uses the same proven technology as the CDK700. Many CDK700s are deployed around the world at various institutions such as: Caltech, Harvard, Penn State, University of New South Wales, Simon Frasier University, University of Montana and University of Hamburg, and many more.
The CDK (Corrected Dall-Kirkham) Optical Design is an innovative solution for unsurpassed scientific investigation, visual observing and astro-imaging at an affordable price. It has excellent performance with large format CCD cameras, far exceeding the off-axis performance of most commercial telescope designs, including the uncorrected Ritchey-Chrétien.
Our design produces a flat, coma-free and astigmatic-free field of view. Since the secondary mirror is spherical, centering is very forgiving, making it easy to align the telescope optics for optimum performance. The end result at the image plane is no off-axis coma, no off-axis astigmatism, and a perfectly flat field to the edge of a 100mm image circle. The stars will be pinpoints from the center to the corner of the field of view.
|Optical Design||Corrected Dall-Kirkham (CDK)|
|Aperture||1000 mm (39.37inch)|
|Focal Length||6000 mm|
|Central Obstruction||47% of the Primary Mirror Diameter|
|Back Focus||373mm (14.7 inches) from Mounting Surface of de-rotator|
|Optical Tube||Dual truss structure with Nasmyth focus ports|
|Optical Performance||3.7 micron RMS spots [35mm on-axis] (400 to 900nm) 5.0 micron RMS spots [50mm off-axis] (400 to 900nm) Spot Diagram Vignetting Diagram|
|Dimensions||135″ H x 72″ W x 45″|
|Optimal Field of View||100mm (1.0 degrees)|
|Focus Position||Dual Nasmyth Focus Ports|
|Image Scale||29 microns per arcsecond at F/6|
|Fork Assembly||Space Frame Steel Truss|
|Fork Base||Welded stainless steel torsion box|
|Azimuth Bearing||Dual 11.125 inch tapered roller bearings|
|Altitude Bearing||Three 9.5 inch 4 way loaded ball bearings (two pre-loaded on motor side and one on non motor side)|
|Optical Tube||Dual truss structure with Nasmyth focus|
|Instrument Payload||300 lbs (150 ft-lbs) – mounted on the field de-rotator plate|
|Motor Control||Industrial grade Parker brushless motor control system and built in electronics|
|Motor – Azimuth and Altitude||Direct Drive 3 Phase Axial-Flux Torque Motor|
|Encoder – Azimuth and Altitude||Absolute encoder with a resolution of 0.078 arcseconds (16.5 million counts per revolution)|
|Motor Torque||Greater than 200 ft-lbs of peak torque|
|Drive Electronics||Controls the altitude and azimuth motors and encoders, 2 direct drive de-rotators with absolute encoders, 4 fans zones, 3 dew heater zones, two focusers, an array of temperature sensors, M3 port selector, primary mirror covers and magnetic axis deceleration|
|Telescope Control Software||Incorporates PointXP mount modeling software and All Sky PlateSolve both by Dave Rowe. Also included is automatic focusing, dew heater control, primary mirror cover control, dome control and all ASCOM compatible. Linux and Windows compatible.|
|Pointing Accuracy||Better than 10 arcsecond RMS with PointXP Model|
2 arcseconds at sidereal velocity
< 1 arcsecond over a 10 minute period at sidereal velocity
|System Natural Frequency||10 Hz or greater|
|Field De-Rotator Accuracy||< 3 microns of peak to peak error at 35mm off-axis over 1 hour of tracking (18 arc sec)|
|Radius of Curvature||6260 mm (246.46 inches)|
|Optical Diameter||1000 mm (39.4 inch)|
|Outer Diameter||1020mm (40.157inch)|
|Core Diameter||360.7 mm (14.2 inches)|
|Primary Thickness||85 mm (3.3 inches)|
|Primary Weight||122 lbs. (54% light weighted)|
|Radius of curvature||5740 mm (226 inches)|
|Optical Diameter||450 mm (17.7 inches)|
|Secondary Weight||27.2 lbs|
|Optical Major Diameter||404 mm (15.9 inches)|
|Optical Minor Diameter||286 mm (11.3 inches)|
|M3 Thickness||65 mm (2.6 inches)|