Sierra Remote Observatories

place Location

latitude 37° 04' 13" N
Longitude 119° 24' 47" W

The Sierra Nevada Mountains of central California offer a superb location for remote imaging. The atmospheric conditions allow the seeing to hover around an incredible 1 arc-second for the majority of the time. The site offers a low incidence of thunderstorm activity and an unusually high number of photometric nights each year.

At 4,610 feet, the site is above the fog and thermal inversion layer that hangs over most parts of California. The site is not too high as to interfere with access in the Winter. "Sierra Remote" is located on top of Bald Mountain and is about an hour's drive from Fresno Yosemite International airport.

devices Instruments

0.7m CDK700 Telescope System

  • Pinpoint stars out to a 70mm image circle
  • Dual Nasmyth focus, allowing simultaneous mounting of two instruments or easy switching between visual and imaging use
  • Direct-drive motors on each axis for smooth, fast, and virtually silent movement of the telescope
  • High resolution encoders on each axis for precise positioning
  • Zero backlash
  • Zero periodic error
  • PointXP mount modeling software
  • Field de-rotator / rotational field framing
Optical Design Corrected Dall-Kirkham (CDK)
Aperture 700 mm (27.56 inch)
Focal Length 4540 mm
Focal ratio 6.5
Central Obstruction 47% of the Primary Mirror Diameter
Back Focus 305 mm (12 inch) from Mounting Surface
Weight 1,200 lbs
Optical Tube Dual truss structure with Nasmyth focus
Optical Performance 1.8 micron RMS spots [25mm on-axis] (400 to 900nm) 4.4 micron RMS spots [21mm off-axis] (400 to 900nm) 6.8 micron RMS spots [35mm off-axis] (400 to 900nm) Spot Diagram  
Dimensions 93.73" H x 43.25" W x 39" D    
Optimal Field of View 70 mm (0.86 degrees) / 51.6 arcminute
Focus Position Nasmyth Focus
Fully Baffled Field 60 mm
Image Scale 22 microns per arcsecond

CCD Camera

PlaneWave is an authorized dealer for Finger Lake Instruments Cameras and can provide all the most popular cameras including the ProLine Series.

ProLine sets the standards in key performance areas that include: Download Speeds, Cooling, Low Noise Operation, Anti-Ghosting Technology, Image Quality, and Linearity. ProLine download speeds are fast while maintaining low-noise frame quality. ProLine achieves outstanding cooling without water assist. Simply set the ProLine cooling where you want it and the camera will do the rest – quickly and without worries. ProLine frame quality is second to none thanks to careful design, implementation and setup. All cameras are assembled in our clean room under exacting conditions and must pass a battery of tests before being shipped.

Camera 1 ProLine PL16803 Monochrome CCD Camera

Camera 2 ProLine PL4240 Grade 1 CCD Camera

PL16803 Specifications PL4240 Specifications
Sensor KAF-16803 CCD42-40
Array Size 4096 x 4096 2048 x 2048
Pixel Size 9 μm 13.5 μm
Typical Maximum Cooling -60º C Below Ambient -65º C Below Ambient
Typical Download Speeds @ 16-bit 1 MHz, 8 MHz (other speeds available) 500 kHz (up to 6 MHz available)
Typical System Noise 10 e- RMS @ 1 MHz 8 e- RMS @ 500 kHz
Nonlinearity <1%
Operating Environment -30º C - 45º C | 10% - 90% Relative Humidity
Sensor Manufacturer Kodak E2V
CCD Type Front Illuminated Front / Back Illuminated
Mega Pixels 16.8 4.2
Sensor Diagonal 52.1 m 39.1
Linear Full Well 100,000 e-
Typical Dark Current <0.07 e-/pixel/sec. @ -35º C 0.2 e-/pixel/sec.
Blooming Protection >100X Saturation Exposure None
Available Shutters 65 mm
Shutter MTBF 1,000,000
Power 12v
Interface USB 2.0
Dimensions 6.2 x 6.2 x 3.8 (157.48 x 157.48 x 96.52)
Filter Wheel FLI CL1-10 CFW FLI CFW-5-7



The first FLI CenterLine to be released is the model CL1-10 which holds up to ten 50mm x 50mm square filters in two independently operated wheels. It is powered by two internally mounted stepper motors and two TruMotion synchronous belts. The internal wheels are supported by radial ball bearings that provide a smooth, quiet and repeatable operation.

  • Number of Filter Wheels: 2
  • Number of Filter Positions: 10 (5 per wheel)
  • Filter Thickness Range: 3mm - 5mm
  • Size: 11" x 13.625"
  • Filter Size: 50mm Square
  • Body Thickness: 1.1"
  • Mechanical Connection: Zero Tilt Adapter
  • Interface:: USB 2.0
  • Weight: 5.3lbs

Filter Available : Blue,Green,Red,Lum,Ha,OIII,SII



FLI color filter wheels are used worldwide. A recent application is SOFIA - Stratospheric Observatory for Infrared Astronomy (along with the ProLine camera and Precision Digital Focuser). FLI color filter wheels have also been used for mine monitoring operations in Angola, microscopy research labs as well as dental research. Of course professional and amateur astronomers around the world use them as well

  • Longest Dimension: 9.300" - Body Thickness (minus motor): .7850"
  • Camera Coupling Pocket: 2.930" - Telescope Coupling: 3.005" - 24 UNS-2B
  • Filter Cup: 2.00" wide by 2.00" long by .116" (2.95mm) depth
  • Internal Wheel Material: CNC Machined Aluminum
  • Path Increase: .505"
  • Power Supply Output: 12VDC, 1000 mA - PC Interface: USB
  • Filter Positions: 7 - Recommended Diameter 50mm - Thickness Range 3mm - 5mm
  • Number of Internal Filter Wheels: One - Software Controlled

Filter Available : -