KPL/IK Juno JUNOCAM Instrument Kernel =============================================================================== This Instrument Kernel (IK) file contains optics and detector parameters and FOV definitions for the JUNO Camera (JUNOCAM) instrument. Version and Date ------------------------------------------------------------------------------- Version 0.1 -- September 29, 2016 -- Boris Semenov, NAIF Updated based on [5]. Version 0.0 -- June 9, 2009 -- Boris Semenov, NAIF Initial Release. References ------------------------------------------------------------------------------- 1. Kernel Pool Required Reading 2. GETFOV, getfoc_c, cspice_getfov headers 3. JUNO FK file, latest version 4. JUNOCAM CDR Presentations 5. E-mail from Mike Caplinger, MSSS re actual JUNOCAM parameters, 09/19/16. 6. C.J. Hansen, et al, "Junocam: Juno~s Outreach Camera", Space Sci Rev, DOI 10.1007/s11214-014-0079-x 7. http://www.msss.com/all_projects/junocam.php, accessed 09/29/16 Contact Information ------------------------------------------------------------------------------- Boris V. Semenov, NAIF/JPL, (818)-354-8136, Boris.Semenov@jpl.nasa.gov Implementation Notes ------------------------------------------------------------------------------- This file is used by the SPICE system as follows: programs that make use of this kernel must ``load'' the kernel, normally during program initialization. The SPICE routine FURNSH loads a kernel file into the pool as shown below. CALL FURNSH ( 'frame_kernel_name; ) -- FORTRAN furnsh_c ( "frame_kernel_name" ); -- C cspice_furnsh, frame_kernel_name -- IDL cspice_furnsh( 'frame_kernel_name' ) -- MATLAB Once the file has been loaded, the SPICE routine GETFOV (getfov_c in C, cspice_getfov in IDL and MATLAB) can be used to retrieve FOV parameters for a given instrument or structure. This file was created and may be updated with a text editor or word processor. Naming Conventions ---------------------------------------------------------- All names referencing values in this IK file start with the characters `INS' followed by the NAIF JUNO spacecraft ID number (-61) followed by a NAIF three digit ID code for the camera or one of its spectral bands. This is the full list of names and IDs for the camera and spectral bands described by this IK file: JUNO_JUNOCAM -61500 JUNO_JUNOCAM_BLUE -61501 JUNO_JUNOCAM_GREEN -61502 JUNO_JUNOCAM_RED -61503 JUNO_JUNOCAM_METHANE -61504 The remainder of the keyword name is an underscore character followed by the unique name of the data item. For example, the JUNOCAM "blue" band boresight direction in the JUNO_JUNOCAM frame is specified by: INS-61501_BORESIGHT The upper bound on the length of the name of any data item is 32 characters. If the same item is included in more than one file, or if the same item appears more than once within a single file, the latest value supersedes any earlier values. Instrument Description --------------------------------------------------------- From [7]: Junocam will acquire 3-color (red, green, blue) images of Jupiter during Juno's first seven orbits around the giant planet. The data will be processed and studied by students as part of the Juno Education and Public Outreach effort. The camera, derived from the MSL MARDI instrument, is designed to acquire red-, green- and blue-wavelength images of Jupiter's polar regions and lower-latitude cloud tops during Juno's first seven orbits around the planet. These images, of approximately 15 kilometers (9.3 miles) per pixel resolution, will be used by students to create the first color images of the jovian poles, as well as high resolution views of lower-latitude cloud belts. After the required, seven orbit design life, Junocam will continue to operate as long as possible in the harsh jovian radiation environment. For a detailed description see [6] Mounting Alignment -------------------------------------------------------- Refer to the latest version of the Juno Frames Definition Kernel (FK) [3] for the JUNOCAM frame definitions and mounting alignment information. Apparent FOV Layout -------------------------------------------------------- The diagram below illustrates the JUNOCAM camera FOV/CCD layout: --- 0,0--------------------------------------------. 4.94 deg | METHANE 128 pix * | -------- --- `-----------------------------------------1600,128 | 245 pixels | --- 0,0--------------------------------------------. | 4.94 deg | BLUE 128 pix * | | --- --- `-----------------------------------------1600,128 | |80 pixels +Zjc x-------------> +Xjc --- --- --- 0,0---------------------|----------------------. | |75 pixels 4.94 deg | GREEN 128 pix * | | --- --- `----------------------|------------------1600,128 | | | --- 0,0---------------------|----------------------. | 230 pixels 4.94 deg | RED 128 pix * | -------- --- `----------------------|------------------1600,128 | V +Yjc | 61.69 deg | Boresight |---------------------------------------------| (+Zjc axis) | | is into the page Optical and Detector Parameters -------------------------------------------------------- This section provides two parameters that, in combination with the optical distortion and filter parameters, are needed to compute the view directions of the individual CCD pixels. These parameters are the focal length and pixel size, both given in millimeters. \begindata INS-61500_FOCAL_LENGTH = ( 10.997 ) INS-61500_PIXEL_SIZE = ( 0.0074 ) \begintext FOV Definition -------------------------------------------------------- This section contains definitions of the JUNOCAM band and total FOVs. All FOVs are defined as rectangular pyramids using boundary vectors consistent with the information provided in the "Apparent FOV Layout" section above. The total FOV (ID -61500), spanning from the METHANE top edge to the RED bottom edge is provided solely for convenience. \begindata INS-61504_FOV_FRAME = 'JUNO_JUNOCAM' INS-61504_FOV_SHAPE = 'RECTANGLE' INS-61504_BORESIGHT = ( 0.00000000 -0.16411733 0.98644082 ) INS-61504_FOV_BOUNDARY_CORNERS = ( -0.51222635 -0.18324426 0.83907432 0.51222635 -0.18324426 0.83907432 0.51222635 -0.09830583 0.85320580 -0.51222635 -0.09830583 0.85320580 ) INS-61501_FOV_FRAME = 'JUNO_JUNOCAM' INS-61501_FOV_SHAPE = 'RECTANGLE' INS-61501_BORESIGHT = ( 0.00000000 -0.05380687 0.99855136 ) INS-61501_FOV_BOUNDARY_CORNERS = ( -0.51222635 -0.08914457 0.85421157 0.51222635 -0.08914457 0.85421157 0.51222635 -0.00316334 0.85884467 -0.51222635 -0.00316334 0.85884467 ) INS-61502_FOV_FRAME = 'JUNO_JUNOCAM' INS-61502_FOV_SHAPE = 'RECTANGLE' INS-61502_BORESIGHT = ( 0.00000000 0.05044689 0.99872675 ) INS-61502_FOV_BOUNDARY_CORNERS = ( -0.51222635 0.00027370 0.85885045 0.51222635 0.00027370 0.85885045 0.51222635 0.08627003 0.85450667 -0.51222635 0.08627003 0.85450667 ) INS-61503_FOV_FRAME = 'JUNO_JUNOCAM' INS-61503_FOV_SHAPE = 'RECTANGLE' INS-61503_BORESIGHT = ( 0.00000000 0.15415234 0.98804709 ) INS-61503_FOV_BOUNDARY_CORNERS = ( -0.51222635 0.08968899 0.85415458 0.51222635 0.08968899 0.85415458 0.51222635 0.17476574 0.84088115 -0.51222635 0.17476574 0.84088115 ) INS-61500_FOV_FRAME = 'JUNO_JUNOCAM' INS-61500_FOV_SHAPE = 'RECTANGLE' INS-61500_BORESIGHT = ( 0.00000000 0.00000000 1.00000000 ) INS-61500_FOV_BOUNDARY_CORNERS = ( -0.51222635 -0.18324426 0.83907432 0.51222635 -0.18324426 0.83907432 0.51222635 0.17476574 0.84088115 -0.51222635 0.17476574 0.84088115 ) \begintext Optical Distortion -------------------------------------------------------- From [5]: The Junocam lens has low distortion (less than 3% at the field corners, primarily barrel distortion.) Low distortion was needed so that TDI could be employed. Because of this, Junocam can be modeled to first order using a simple f tan(theta) pinhole camera model. This can be further improved by adding one radial distortion term k1 of value 3.839251e-8; that is, x' = x*(1 + k1 * r**2) and y' = y*(1 + k1 * r**2), r**2 = x**2 + y**2, where x,y is the ideal f tan(theta) pixel coordinate and x',y' is the observed distorted pixel coordinate. This reduces residuals across the field to less than two pixels. The K1 value is provided in the keyword below. \begindata INS-61500_DISTORTION_K1 = 3.839251e-8 \begintext Filters -------------------------------------------------------- TBD; may be based on MRO/MARCI A Recipe for Computing Observation Time and CCD Pixel View Direction -------------------------------------------------------------------- TBD; may be based on MRO/MARCI End of the IK file.