KPL/IK LUCY L'TES Instrument Kernel =============================================================================== This Instrument Kernel (IK) file contains Lucy Thermal Emission Spectrometer (L'TES) optics, detector, and field-of-view parameters. Version and Date ------------------------------------------------------------------------------- Version 0.1 -- March 2, 2020 -- Boris Semenov, NAIF - Added the 85% and 50% Encircled Energy FOV definitions (for IDs -49401 and -49402) - Updated the TES FOV half size to include an additional significant digit (0.229 -> 0.2292) Version 0.0 -- October 15, 2019 -- Boris Semenov, NAIF - Initial version based on [4] References ------------------------------------------------------------------------------- 1. Kernel Pool Required Reading 2. Frames Required Reading 3. Lucy Frames Kernel, latest version 4. OSIRIS-REx OTES IK, orx_otes_v00.ti 5. L'TES Instrument CDR materials, LTES_CDR_03122019.pdf 6. TES to Lucy ICD, LUCY-RQ-17-SE-5C, latest version 7. Review comments on initial Lucy FK/IK, David E. Kaufmann, SWRI, February 17, 2020 Contact Information ---------------------------------------------------------- Boris 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 frame kernel must `load' the kernel, normally during program initialization. Loading the kernel associates the data items with their names in a data structure called the "kernel pool". The SPICE API FURNSH loads a kernel into the pool as shown below: FORTRAN (SPICELIB): CALL FURNSH ( 'frame_kernel_name' ) C (CSPICE): furnsh_c ( "frame_kernel_name" ); IDL (ICY): cspice_furnsh, 'frame_kernel_name' MATLAB (MICE): cspice_furnsh ( 'frame_kernel_name' ) PYTHON (SPICEYPY): spiceypy.furnsh( 'frame_kernel_name' ) This file was created and may be updated with a text editor or word processor. Naming Conventions ---------------------------------------------------------- All names referencing values in this I-kernel start with the characters `INS' followed by the NAIF Lucy spacecraft ID number (-49) followed by a NAIF three digit ID code for the L'TES instrument, defined in [3] as: LUCY_TES -49400 LUCY_TES_85 -49401 LUCY_TES_50 -49402 LUCY_TES_SUNKOZ -49499 The remainder of the name is an underscore character followed by the unique name of the data item. For example, the L'TES boresight direction in the L'TES frame (``LUCY_TES'' -- see [3]) is specified by: INS-49400_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 [?]: TBD -- description in this section should be similar in scope to descriptions provided in other Lucy instrument IKs Mounting Alignment -------------------------------------------------------- Refer to the latest version of the LUCY Frames Definition Kernel (FK) [3] for the instrument reference frame definitions and mounting alignment information. L'TES Field of View Parameters ---------------------------------------------------------- TES Instrument FOV Definition The TES frame is defined such that the boresight is the frame's -Z axis. Per [5], the field of view is circular with a 8 milliradian angular size (4 milliradian = 0.2292 deg half extent). A cross section is illustrated below. (Note we are arbitrarily choosing vectors that terminate in the Z=-1 plane.) ^ X | inst | |. | | `. | | `. | | o. | |0.229 `. | <---------------x -Z | ,' Y (in) inst | ,' inst | ,' | ,' |' |--- 1.0 ---| Plane Y = 0 Because the TES field of view is circular, the FOV reference vector (keyword FOV_REF_VECTOR) can be any vector with a component that lies in a plane normal to the field of view boresight. We chose the +X axis of the instrument frame. This FOV half extent value is given in the keywords below: \begindata INS-49400_FOV_CLASS_SPEC = 'ANGLES' INS-49400_FOV_SHAPE = 'CIRCLE' INS-49400_FOV_FRAME = 'LUCY_TES' INS-49400_BORESIGHT = ( 0.0, 0.0, -1.0 ) INS-49400_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-49400_FOV_REF_ANGLE = ( 0.2292 ) INS-49400_FOV_ANGLE_UNITS = ( 'DEGREES' ) \begintext TES 85% and 50% Encircled Energy FOV Definitions The TES 85% and 50% Encircled Energy FOVs are defined such that the boresight is the TES frame's -Z axis. Per [7], the 85% Encircled Energy FOV has 8 milliradian angular size (4 mrad = 0.2292 deg half extent), the same as the basic TES FOV defined above, while the 50% Encircled Energy FOV has 6.5 milliradian angular size (3.25 mrad = 0.1862 deg half extent). Because the TES 85% and 50% Encircled Energy field of views are circular, the FOV reference vectors (keyword FOV_REF_VECTOR) can be any vectors with a component that lies in a plane normal to the field of view boresight. We chose the +X axis of the instrument frame. These FOV half extent values are given in the keywords below: \begindata INS-49401_FOV_CLASS_SPEC = 'ANGLES' INS-49401_FOV_SHAPE = 'CIRCLE' INS-49401_FOV_FRAME = 'LUCY_TES' INS-49401_BORESIGHT = ( 0.0, 0.0, -1.0 ) INS-49401_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-49401_FOV_REF_ANGLE = ( 0.2292 ) INS-49401_FOV_ANGLE_UNITS = ( 'DEGREES' ) INS-49402_FOV_CLASS_SPEC = 'ANGLES' INS-49402_FOV_SHAPE = 'CIRCLE' INS-49402_FOV_FRAME = 'LUCY_TES' INS-49402_BORESIGHT = ( 0.0, 0.0, -1.0 ) INS-49402_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-49402_FOV_REF_ANGLE = ( 0.1862 ) INS-49402_FOV_ANGLE_UNITS = ( 'DEGREES' ) \begintext Sun Damage Keep-out Zone (SUNKOZ) FOV Definition Per [6], SUNKOZ FOV is an 20 degree (10 degrees half extent) circle centered on the instrument frame's -Z axis: ^ X | inst | |. | | `. | | `. | | o`. | |10.0 `. | <---------------x -Z | ,' Y (in) inst | ,' inst | ,' | ,' |' |--- 1.0 ---| Plane Y = 0 This FOV is defined below: \begindata INS-49499_FOV_CLASS_SPEC = 'ANGLES' INS-49499_FOV_SHAPE = 'CIRCLE' INS-49499_FOV_FRAME = 'LUCY_TES' INS-49499_BORESIGHT = ( 0.0, 0.0, -1.0 ) INS-49499_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-49499_FOV_REF_ANGLE = ( 10.0 ) INS-49499_FOV_ANGLE_UNITS = ( 'DEGREES' ) \begintext End of the IK file.