KPL/IK Hayabusa2 LIDAR Instrument kernel ============================================================================== This instrument kernel (I-kernel) file contains detector, optical, and field-of-view parameters for the Hayabusa2 LIDAR (Light Detection And Ranging) instrument. Version and Date ------------------------------------------------------------------------------ Version 2.0 -- 19, Feb., 2023 -- Shin-ya Murakami (ISAS, JAXA, Japan) -- version of the file is set to 2.0. -- Applied cosmetic changes. Version 1.05 -- 10, Mar., 2020 -- Hirotomo Noda and Koji Matsumoto (NAOJ, Japan) -- revision: replaced one reference, added contact information, removed alignment description (moved to FK), removed unnecessary items, and rewrote instrument description. Version 1.04 -- 5, Aug., 2019 -- Shin-ya Murakami (JAXA, Japan) -- revision: applied cosmetic changes. Version 1.03 -- 18, Nov., 2016 -- Yukio Yamamoto (JAXA, Japan) -- revision: boresight direction is fixed to (0,0,1) and the frame kernel absorbs the experimental results. Version 1.02 -- 21, Jan., 2016 -- Hirotomo Noda (NAOJ, Japan) -- revision: boresight direction is determined from experimental results of laser link (Orbit info was included for boresight estimation) Version 1.01 -- 12, Jan., 2016 -- Hirotomo Noda (NAOJ, Japan) Version 1.0 -- 8, Sep., 2015 -- Hirotomo Noda (NAOJ, Japan) Reference ------------------------------------------------------------------------------ 1. Kernel Pool Required Reading 2. GETFOV, getfoc_c, cspice_getfov headers 3. Hayabusa2 Frames Definition Kernel, latest version 4. Mizuno et al., 2017, Development of the Laser Altimeter (LIDAR) for Hayabusa2, Space Sci. Rev., 208, 33-47, DOI 10.1007/s11214-015-0231-2 5. Spacecraft planning document (PMY-014052), JAXA document, December 2014 Contact Information ------------------------------------------------------------------------------ Hirotomo Noda, National Astronomical observatory of Japan (NAOJ), hirotomo.noda@nao.ac.jp Koji Matsumoto, National Astronomical observatory of Japan (NAOJ), koji.matsumoto@nao.ac.jp 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 Hayabusa2 ID number (-37) followed by a NAIF three digit ID code for one of LIDAR: HAYABUSA2_LIDAR -37400 The remainder of the keyword name is an underscore character followed by the unique name of the data item. For example, the boresight direction of HAYABUSA2_LIDAR is specified by: INS-37400_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 ------------------------------------------------------------------------------ The LIght Detection And Ranging (LIDAR) laser altimeter on Hayabusa2 is an instrument for measuring distance between spacecraft and the surface of the asteroid. Because the LIDAR is used as a navigation sensor for rendezvous, approach, and touchdown procedures, it has a wide dynamic range, from 25 km to 30 m. To achieve this wide dynamic range, the LIDAR consists of two receiving telescopes; one is for long range (25 km to 300 m) and the other is for short range (shorter than 300 m). Details on instrumentation is described in [4], and the block diagram is found in Figure 3 of the paper. Mounting Alignment ------------------------------------------------------------------------------- Refer to the latest version of the Hayabusa2 Frames Definition Kernel (FK) [3] for the instrument reference frame definitions and mounting alignment information. Instrument FOV Definition(s) ------------------------------------------------------------------------------- Hayabusa2 LIDAR has two receiving telescopes to cover wide range of the measurement distance (25 km to 30 m). Short-range telescope, whose full-angle FOV size is 20.4 mrad, is used only when the distance toward the asteroid surface is shorter than 300 meters. Described below is the FOV definition of the long-range telescope. The full-angle FOV size of the long-range receiving telescope is 1.5 mrad, therefore the corresponding half angle is 0.75 mrad. The BORESIGHT direction below, that is defined in the HAYABUSA2_LIDAR frame, is almost parallel to -Z axis of the BUS_PRIME coordinate. \begindata INS-37400_FOV_FRAME = 'HAYABUSA2_LIDAR' INS-37400_FOV_SHAPE = 'CIRCLE' INS-37400_BORESIGHT = ( 0.0, 0.0, +1.0 ) INS-37400_FOV_BOUNDARY_CORNERS = ( 0.00000, 0.00075, +1.00000 ) \begintext LIDAR location with respect to spacecraft center of mass ------------------------------------------------------------------------------- Offset vector from the center of mass of the Hayabusa2 spacecraft to LIDAR origin is estimated as follows: (dX, dY, dZ) = (-0.74, -0.22, -0.70) [m] These values are based on the following calculation. We set the center of mass position of the spacecraft as a fixed value measured on the ground before launch, where temporal changes during the mission phase is ignored: (0.0102, -0.0070, 0.7006) [m], where Z value is measured from the bottom of the spacecraft structure (-Z panel), and the position of (X, Y) = (0, 0) is the center of SCI. These values are quoted from Table 6.6-9 in page 6-14 in [5]. The (X, Y) position of the LIDAR on the -Z panel is estimated from the drawing of Figure 5.2-17 in page 5-21 in [5] as (-0.730, -0.230) [m]. The origin of LIDAR range measurement is spacecraft structural panel (-Z panel) on which LIDAR is mounted. \begindata INS-37400_LOC_FROM_COM = ( -0.74, -0.22, -0.70 ) \begintext End of the IK file.