KPL/IK ROLIS Camera Instrument kernel ============================================================================== This instrument kernel (I-kernel) contains ROLIS optics, detector, and field-of-view parameters. Version and Date ------------------------------------------------------------------------------ Version 0.0 -- Feb 14, 2013 -- Stefano Mottola, DLR Initial release. Version 0.1 -- Jun 11, 2013 -- Stefano Mottola, DLR First update. Version 0.2 -- Jun 17, 2013 -- Stefano Mottola, DLR Boris Semenov, JPL Slight updates name/ID for ROLIS ROS_LANDER_ROLIS_* - Added 55.6 as FOV (close up mode) in the diagram of Apparent FOV Layout. Version 0.3 -- Sep 24, 2014 -- Stefano Mottola, DLR FOV layout corrected. FOV, IFOV and distortion parameters updated. Note on interpretation of the focal length added. References ------------------------------------------------------------------------------ 1. ''Kernel Pool Required Reading'' 2. ''C-kernel Required Reading'' 3. ROLIS EAICD RO-LRS-SP-3030 Issue 1.2 21 Jan 2008. 4. ''The ROLIS experiment on the Rosetta Lander'', Mottola et al., Space Sci Rev., 2007, 128 (1-4), pp. 241-255. Implementation Notes ------------------------------------------------------------------------------ Applications that need SPICE I-kernel data must ''load'' the I-kernel file, normally during program initialization. Loading the kernel using the SPICELIB routine FURNSH causes the data items and their associated values present in the kernel to become associated with a data structure called the ''kernel pool''. The application program may then obtain the value(s) for any IK data item using the SPICELIB routines GDPOOL, GIPOOL, GCPOOL. Routine GETFOV may be used if the file contains instrument field-of-view (FOV) specification. See [1] for details. This file was created with, and can be updated with a text editor or word processor. Conventions for Specifying Data ------------------------------------------------------------------------------ Data items are specified using ''keyword=value'' assignments [1]. All keywords referencing values in this I-kernel start with the characters `INS' followed by the NAIF Dawn instrument ID code, constructed using the spacecraft ID number (-XXX) followed by the NAIF three digit ID number. Instrument name ID -------------------- ------- ROS_LANDER_ROLIS_IFL -226810 ROS_LANDER_ROLIS_R -226811 ROS_LANDER_ROLIS_G -226812 ROS_LANDER_ROLIS_B -226813 ROS_LANDER_ROLIS_IR -226814 The remainder of the keyword is an underscore character followed by the unique name of the data item. For example, the f/ratio is specified by INS-2268XX_F/RATIO The upper bound on the length of all keywords is 32 characters. If a keyword is included in more than one file, or if the same keyword appears more than once within a single file, the last assignment supersedes any earlier assignments. Overview ------------------------------------------------------------------------------ From [3] and [4]: The ROLIS descent and close-up imager comprises - a refractive lens system (one element of which is movable and allows the focus position to be changed between two discrete positions - infinity to 30cm -) - an illumination device consisting of 4 sets of LEDs for post-landing close-up imaging - an Atmel/Thomson TH7888A CCD at the focal plane. The active area of the CCD is sized 1024 x 1024 pixels or 14.34 x 14.34 mm (14.00 x 14.00 micron per pixel). Apparent FOV Layout ------------------------------------------------------------------------------ This section provides a diagram illustrating the ROLIS apparent FOV layout in the corresponding reference frames. Xlnd, Ylnd, Zlnd are the axes of the lander reference system as defined in [3]. XRolfrm, YRolfrm, ZRolfrm are the axes of the ROLIS frame reference system. Pixel (1,1) is in the lower left corner of the image, and pixel (1024,1024) is in the top right corner. The boresight direction is along -Zlnd and +ZRolfrm and is directed out of the page. +Zlnd is directed into the page. +ZRolfrm is directed out of the page. 55.6 deg | 56.6 deg (IFL) | |<----------------->| | | 1024 columns +Ylnd +Zlnd +YRolfrm ^ <------------x | (1024,1024) | +---------|---------+ ----- | | | | ^ | | | | | | | | | | | | | | | 55.6 deg | | o------------> | 56.6 deg (IFL) +Xlnd v | +ZRolfrm +XRolfrm | | | | 1024 lines | | | | | v +-------------------+ ----- (1,1) Optical Parameters ------------------------------------------------------------------------------ The following ROLIS nominal first order optical parameters are, from [4]: ------------------------------------------------------------------ parameter Infinity mode Close-up mode ------------------------------------------------------------------ Focal Length, mm 13.3 13.59 f/ratio f/5.0 f/5.0 IFOV, rad/pixel 0.00105 0.00103 Field of view, deg 56.6 55.6 Field of view, rad 0.988636 0.970726 ------------------------------------------------------------------ Note: The value listed as Focal Length for the Close-up mode represents in reality the distance between the image plane and the rear principal point of the optics. This choice has been made in order to allow the programs that automatically compute the FOV from this focal length entry (and that generally assume the object at infinity) to obtain the correct values of the FOV also in close-up mode. ROLIS optical parameters \begindata INS-226810_FOCAL_LENGTH = ( 13.450 ) INS-226810_IFOV = ( 0.00104, 0.00104 ) INS-226810_FOV_ANGULAR_SIZE = ( 0.979297, 0.979297 ) INS-226810_F/RATIO = ( 5.0 ) INS-226811_FOCAL_LENGTH = ( 13.530 ) INS-226811_IFOV = ( 0.00103, 0.00103 ) INS-226811_FOV_ANGULAR_SIZE = ( 0.974382, 0.974382 ) INS-226811_F/RATIO = ( 5.0 ) INS-226812_FOCAL_LENGTH = ( 13.574 ) INS-226812_IFOV = ( 0.00103, 0.00103 ) INS-226812_FOV_ANGULAR_SIZE = ( 0.971699, 0.971699 ) INS-226812_F/RATIO = ( 5.0 ) INS-226813_FOCAL_LENGTH = ( 13.551 ) INS-226813_IFOV = ( 0.00103, 0.00103 ) INS-226813_FOV_ANGULAR_SIZE = ( 0.973100, 0.973100 ) INS-226813_F/RATIO = ( 5.0 ) INS-226814_FOCAL_LENGTH = ( 13.541) INS-226814_IFOV = ( 0.00103, 0.00103 ) INS-226814_FOV_ANGULAR_SIZE = ( 0.973710, 0.973710 ) INS-226814_F/RATIO = ( 5.0 ) \begintext CCD Parameters ------------------------------------------------------------------------------ ROLIS uses a CCD detector with the following nominal geometry parameters, from [4]. -------------------------------------------- parameter value -------------------------------------------- Pixel Size, microns 14.00 Detector Array Size 1024 Detector Array Center 512.5 -------------------------------------------- The values are given in microns for PIXEL_SIZE keywords and in counts for PIXEL_SAMPLES, PIXEL_LINES, and CENTER keywords. ROLIS detector \begindata INS-226810_PIXEL_SIZE = ( 14.0000, 14.0000 ) INS-226810_PIXEL_SAMPLES = ( 1024 ) INS-226810_PIXEL_LINES = ( 1024 ) INS-226810_CCD_CENTER = ( 512.5, 512.5 ) INS-226811_PIXEL_SIZE = ( 14.0000, 14.0000 ) INS-226811_PIXEL_SAMPLES = ( 1024 ) INS-226811_PIXEL_LINES = ( 1024 ) INS-226811_CCD_CENTER = ( 512.5, 512.5 ) INS-226812_PIXEL_SIZE = ( 14.0000, 14.0000 ) INS-226812_PIXEL_SAMPLES = ( 1024 ) INS-226812_PIXEL_LINES = ( 1024 ) INS-226812_CCD_CENTER = ( 512.5, 512.5 ) INS-226813_PIXEL_SIZE = ( 14.0000, 14.0000 ) INS-226813_PIXEL_SAMPLES = ( 1024 ) INS-226813_PIXEL_LINES = ( 1024 ) INS-226813_CCD_CENTER = ( 512.5, 512.5 ) INS-226814_PIXEL_SIZE = ( 14.0000, 14.0000 ) INS-226814_PIXEL_SAMPLES = ( 1024 ) INS-226814_PIXEL_LINES = ( 1024 ) INS-226814_CCD_CENTER = ( 512.5, 512.5 ) \begintext LED Parameters ------------------------------------------------------------------------------ This section contains ROLIS LED parameters. The illumination device is used to obtain multi-spectral images when ROLIS is in close-up mode. It consists of an array of 144 LEDs arranged in 36 quadruplets each containing a blue, green, red and near-infrared diode. During the descent mode (IFL) no illumination device is used and the images are acquired in clear filter, for which the equivalent band center and bandwidth are given. The following emission band center and band width data are taken from [4]. FWHM is the Full Width at Half Maximum. ----------------------------- filter band FWHM # center ----------------------------- IFL 750 400 R 645 45 G 540 85 B 475 50 IR 875 85 ----------------------------- Given below are the center wavelength (BANDCENTER) and the FWHM (BANDWIDTH) for each of the LED bands, all in nm. ROLIS LEDS \begindata INS-226810_BANDCENTER = ( 750 ) INS-226810_BANDWIDTH = ( 400 ) INS-226811_BANDCENTER = ( 645 ) INS-226811_BANDWIDTH = ( 45 ) INS-226812_BANDCENTER = ( 540 ) INS-226812_BANDWIDTH = ( 85 ) INS-226813_BANDCENTER = ( 475 ) INS-226813_BANDWIDTH = ( 50 ) INS-226814_BANDCENTER = ( 875 ) INS-226814_BANDWIDTH = ( 85 ) \begintext FOV Definitions ------------------------------------------------------------------------------ This section contains definitions for the ROLIS FOV. These definitions are provided in a format required by the SPICE (CSPICE) function GETFOV (getfov_c). The set of assignments in the data section below defines the ROLIS FOVs with respect to the ROLIS frame to be a rectangle with the corners defined by the first and last pixels of the first and last lines of the CCD and the boresight along the +Z axis. This FOV definition uses the FOV_ANGULAR_SIZE values from the ''Optical Parameters'' section above converted to degrees. ROLIS FOV \begindata INS-226810_FOV_FRAME = 'ROS_LANDER_ROLIS' INS-226810_FOV_SHAPE = 'RECTANGLE' INS-226810_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-226810_FOV_CLASS_SPEC = 'ANGLES' INS-226810_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-226810_FOV_REF_ANGLE = ( 28.05480 ) INS-226810_FOV_CROSS_ANGLE = ( 28.05480 ) INS-226810_FOV_ANGLE_UNITS = 'DEGREES' INS-226811_FOV_FRAME = 'ROS_LANDER_ROLIS' INS-226811_FOV_SHAPE = 'RECTANGLE' INS-226811_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-226811_FOV_CLASS_SPEC = 'ANGLES' INS-226811_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-226811_FOV_REF_ANGLE = ( 27.91400 ) INS-226811_FOV_CROSS_ANGLE = ( 27.91400 ) INS-226811_FOV_ANGLE_UNITS = 'DEGREES' INS-226812_FOV_FRAME = 'ROS_LANDER_ROLIS' INS-226812_FOV_SHAPE = 'RECTANGLE' INS-226812_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-226812_FOV_CLASS_SPEC = 'ANGLES' INS-226812_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-226812_FOV_REF_ANGLE = ( 27.83712 ) INS-226812_FOV_CROSS_ANGLE = ( 27.83712 ) INS-226812_FOV_ANGLE_UNITS = 'DEGREES' INS-226813_FOV_FRAME = 'ROS_LANDER_ROLIS' INS-226813_FOV_SHAPE = 'RECTANGLE' INS-226813_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-226813_FOV_CLASS_SPEC = 'ANGLES' INS-226813_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-226813_FOV_REF_ANGLE = ( 27.87726 ) INS-226813_FOV_CROSS_ANGLE = ( 27.87726 ) INS-226813_FOV_ANGLE_UNITS = 'DEGREES' INS-226814_FOV_FRAME = 'ROS_LANDER_ROLIS' INS-226814_FOV_SHAPE = 'RECTANGLE' INS-226814_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-226814_FOV_CLASS_SPEC = 'ANGLES' INS-226814_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-226814_FOV_REF_ANGLE = ( 27.89474 ) INS-226814_FOV_CROSS_ANGLE = ( 27.89474 ) INS-226814_FOV_ANGLE_UNITS = 'DEGREES' \begintext Optical Distortion ------------------------------------------------------------------------------ This section provides optical distortion and geometric calibration data for ROLIS. A 3d vector (P) in the camera frame is mapped into sample and line (S,L) coordinates in pixels through these equations: ( X ) FL ( P(1) ) ( ) = ------ ( ) ( Y ) P(3) ( P(2) ) where X and Y are the horizontal and vertical distance in millimeters from the center of the CCD. The X and Y directions are defined in the ''Apparent FOV Layout'' section. FL is the focal length in millimeters. R*R = X*X + Y*Y ( dX ) ( X*R*R ) ( ) = E1 ( ) ( dY ) ( Y*R*R ) ( S ) ( Kx 0 ) ( X + dX ) ( S0 ) ( ) = ( ) ( ) + ( ) ( L ) ( 0 Ky ) ( Y + dY ) ( L0 ) S0 and L0 refer to the position of the optical axis on the CCD in pixels, and are equal to the elements of the CCD_CENTER keyword defined in the ''CCD Parameters'' section. The constants Kx and Ky map millimeters to pixels in the focal plane X and Y directions. They are identical to the inverse of the pixel size in millimeters in the X and Y directions. The pixel size in microns is defined by the PIXEL_SIZE keyword in the ''CCD Parameters'' section. E1 is the first radial distortion coefficient. It is a function of wavelength, and as such different for each filter. It has units of 1/(mm*mm). ROLIS distortion \begindata INS-226810_RAD_DIST_COEFF = ( -4.9543E-5 ) INS-226811_RAD_DIST_COEFF = ( -1.1214E-5 ) INS-226812_RAD_DIST_COEFF = ( -3.5847E-5 ) INS-226813_RAD_DIST_COEFF = ( -3.2937E-5 ) INS-226814_RAD_DIST_COEFF = ( -1.1819E-5 ) \begintext End of IK file.