PlaneWave 1 Meter Alt-Az Telescope

PlaneWave 1 Meter Alt-Az Telescope

PlaneWave 1 Meter Alt-Az Telescope

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.

Proven Technology of the CDK700

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. Durango Skies has also installed CDK700s in private observatories.

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.

Five CDK700 telescopes at the Caltech/MINERVA installation on Mount Hopkins, Arizona
Five CDK700 telescopes at the Caltech/MINERVA installation on Mount Hopkins, Arizona

The PlaneWave 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.

PW1000 Optical Design

PW1000 Mechanical features

PW1000 Motor System

PlaneWave Videos

Optical Specifications

Optical Design: Corrected Dall-Kirkham (CDK) or Ritchey-Chrétien (RC)

Aperture: 1000 mm (39.37 inch)

Focal Length: 6000 mm

Focal ratio: f/6

Central Obstruction: 47% of the Primary Mirror Diameter

Back Focus: 373 mm (14.7 inches) from Mounting Surface of De-Rotator

Weight: 2,600 lb (1,179 kg)

Dimensions: 135" H x 72" W x 45" (3429mm H x 1829mm W x 1143mm)

Optical Tube: Dual truss structure with Nasmyth focus

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 and Diffraction Diagrams)

Optimal Field of View: 100 mm (1.0 degrees)

Focus Position: Dual Nasmyth Focus Ports

Mechanical Specs

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 the motor side and one on the non-motor side

Optical Tube: Dual truss structure with Nasmyth focus

Instrument Payload: 300 lb (150 ft-lb) mounted on the field de-rotator plate

Motion Control

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.

System Performance

Pointing Accuracy: Better than 10 arcsecond RMS with PointXP Model

Pointing Precision: 2 arcsecond

Tracking Accuracy: <1 arcsecond error over 10 minute period

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)

Primary Mirror

Radius of Curvature: 6,260 mm (246.46 inches)

Optical Diameter: 1,000 mm (39.4 inch)

Outer Diameter: 1,020mm (40.157inch)

Core Diameter: 360.7 mm (14.2 inches)

Material: Fused Silica

Thickness: 85 mm (3.3 inches)

Weight: 122 lb (55.3 kg); 54% light weighted

Cell: 18 point

Secondary Mirror

Radius of curvature: 5,740 mm (226 inches)

Optical Diameter: 450 mm (17.7 inches)

Material: Fused Silica

Weight: 27.2 lb (12.3 kg)

Cell: 3 point RTV

Third Mirror

Optical Major Diameter: 404 mm (15.9 inches)

Optical Minor Diameter: 286 mm (11.3 inches)

Material: Fused Silica

Thickness: 65 mm (2.6 inches)