KPL/FK SIRTF Frame Definitions Kernel =============================================================================== This frame kernel contains the SIRTF spacecraft, science instrument and communication antenna frame definitions. Version and Date -------------------------------------------------------- Version 0.3 -- March 13, 2002 -- Boris Semenov Added SIRTF_LGA_COUPLED frame definition. Version 0.2 -- February 12, 2002 -- Boris Semenov Fixed typo in the SIRTF_LGA1_RX frame definition. Version 0.1 -- September 7, 2001 -- Boris Semenov Changed HGA frame definition per Ramona Tung's message from 09/07/01. Version 0.0 -- July 20, 2001 -- Boris Semenov Pre-Release. Contains only nominal antenna frame definitions. References -------------------------------------------------------- 1. ``C-kernel Required Reading'' 2. ``Kernel Pool Required Reading'' 3. ``Frames Required Reading'' 4. SIRTF antennae pattern description. E-mails from R.Tung, JPL TELECOM. June/July/September 2001, March 2002. Contact Information -------------------------------------------------------- Boris V. Semenov, NAIF/JPL, (818)-354-8136, bsemenov@spice.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. The SPICELIB routine FURNSH and CSPICE function furnsh_c load a kernel file into the kernel pool as shown below. CALL FURNSH ( 'frame_kernel_name' ) furnsh_c ( 'frame_kernel_name' ) This file was created and may be updated with a text editor or word processor. SIRTF Frames -------------------------------------------------------- The following SIRTF frames are defined in this kernel file: Frame Name Relative to Type NAIF ID ========================= ========================= ======= ======= Spacecraft Bus Frame: --------------------- SIRTF_SC_BUS rel.to J2000/SUN_POINTING CK -79000 Antenna Frame(s) (-795xx): -------------------------- SIRTF_HGA rel.to SIRTF_SC_BUS FIXED -79500 SIRTF_LGA1_RX rel.to SIRTF_SC_BUS FIXED -79510 SIRTF_LGA2_TX rel.to SIRTF_SC_BUS FIXED -79520 SIRTF_LGA3_RX rel.to SIRTF_SC_BUS FIXED -79530 SIRTF_LGA4_TX rel.to SIRTF_SC_BUS FIXED -79540 SIRTF_LGA_COUPLED rel.to SIRTF_SC_BUS FIXED -79550 SIRTF Frames Hierarchy ------------------------------------------------------------------------------- The diagram below shows SIRTF frames hierarchy: "J2000" INERTIAL -----------------------------------+ | | | | <--pck | V | "IAU_EARTH" | ----------- | | <--ck | V "SIRTF_SC_BUS" +----------------------------------------------------------+ | | | | | | |<--fixed | fixed-->| |<--fixed | fixed-->| | | | | | | V | V V | V "SIRTF_LGA1_RX" | "SIRTF_LGA2_TX" "SIRTF_LGA3_RX" | "SIRTF_LGA4_TX" --------------- | --------------- --------------- | --------------- | | |<--fixed fixed-->| | | V V "SIRTF_HGA" "SIRTF_LGA_COUPLED" ----------- ------------------- Spacecraft Bus Frame -------------------------------------------------------- The spacecraft bus frame is defined by the spacecraft design as follows: * +X axis is along the telescope nominal boresight; * +Z axis is normal to the nominal solar array surface and points away from it; * +Y axis completes the right hand frame; * the origin of this frame is at center of the focal plane of the telescope; These diagrams illustrate the spacecraft bus frame: Spacecraft +Y side view: ------------------------ . .'| ._______. | | Solar Array Telescope | +Xsc | | | | ^ | | | | | | | | | | | | | | | | | | | | | | | |___|__ | | | /__ o-----------> +Zsc | +Ysc | | | |(out of | | | | page) | | | | | | | | | | | | | `.| |_________| || / \ || ===============|| | | | ||| | | | ||| | | | ||| | | | ||| ===============|| / _..-'' || /..-''\| `| o HGA Spacecraft +X side view: ------------------------ __|| Solar Array ._______./ || Telescope `. || . .___. .|| | .'+Xsc `. ||| | | o-----------> +Zsc | `._|_.' ||| `. | .'|| `.___|___.' || | \__|| | || | V +Ysc Spacecraft bus attitude with respect to an inertial frame is provided by a C kernel (see [1] for more information). \begindata FRAME_SIRTF_SC_BUS = -79000 FRAME_-79000_NAME = 'SIRTF_SC_BUS' FRAME_-79000_CLASS = 3 FRAME_-79000_CLASS_ID = -79000 FRAME_-79000_CENTER = -79 CK_-79000_SCLK = -79 CK_-79000_SPK = -79 \begintext SIRTF Antenna Frames -------------------------------------------------------- The frame for each of five antennas -- HGA, two +Y side LGAs and two -Y side LGAs -- is defined as follows: * +Z axis is the antenna boresight direction; * +X axis is the antenna pattern clock angle reference axis; * +Y axis completes the right hand frame; * the origin of this frame is at the center of the antenna dish (for HGA) or plate (for LGAs); HGA Frame -------------------------------------------------------- This diagram illustrates the HGA frame: Spacecraft +Y side view: ------------------------ . .'| ._______. | | Solar Array Telescope | +Xsc | | | | ^ | | | | | | | | | | | | | | | | | | | | | | | |___|__ | | | /__ o-----------> +Zsc | +Ysc | | | |(out of | | | | page) | | | | | | | | | | | | | `.| |_________| || / \ || ===============|| | | | ||| | | | ||| | | | ||| | | | ||| ===============|| / _..-'' HGA /..-''\| _-> +Yhga _..o'' (appox. +Xhga <' \ into the (appox. \ page) into the | \ page) | V +Zhga | |------>\ 8 deg. As seen on the diagram, the HGA boresight is 8 degrees off the s/c -X axis toward the s/c +Z axis (see [4]). After the HGA +Z axis is co-aligned with the HGA boresight, another rotation -- by -135 degrees about boresight -- is needed to co-align the HGA +X with the the antenna pattern clock angle reference direction. Thus, two rotations -- first by -82 degrees about +Y axis, and second by -135 degrees about +Z axis -- are needed to co-align the s/c frame with the HGA frame. The SIRTF_HGA frame definition below implements this orientation. Since the SPICE frames subsystem calls for specifying the reverse transformation--going from the instrument or structure frame to the base frame--as compared to the description given above, the order of rotations assigned to the TKFRAME_*_AXES keyword is also reversed compared to the above text, and the signs associated with the rotation angles assigned to the TKFRAME_*_ANGLES keyword are the opposite from what is written in the above text. \begindata FRAME_SIRTF_HGA = -79500 FRAME_-79500_NAME = 'SIRTF_HGA' FRAME_-79500_CLASS = 4 FRAME_-79500_CLASS_ID = -79500 FRAME_-79500_CENTER = -79 TKFRAME_-79500_SPEC = 'ANGLES' TKFRAME_-79500_RELATIVE = 'SIRTF_SC_BUS' TKFRAME_-79500_ANGLES = ( 0, 82.0, 135.0 ) TKFRAME_-79500_AXES = ( 1, 2, 3 ) TKFRAME_-79500_UNITS = 'DEGREES' \begintext Individual LGA Frames -------------------------------------------------------- This diagram based on [4] illustrates the individual LGA frames: Spacecraft +X side view: ------------------------ +Zlga2 +Zlga1 ^ ^ | | | | | | o-------> +Ylga2 +Ylga1 <-------x | |___| | || Solar array LGA2.' `.LGA1 .' .___. `.|| | .'+Xsc `. ||| | | o-----------------> +Zsc | `._|_.' ||| `. | .'|| LGA4 _|_ .'LGA3 | | | | | || x-------> +Ylga4 +Ylga3 <-------o +Xsc is out of the page | | | +Xlga1 is into the page | | | +Xlga2 is out of the page V | | +Xlga3 is out of the page +Zlga4 | V +Xlga4 is into the page | +Zlga3 | V +Ysc As seen on the diagram, the antenna frames are rotated from the s/c frame as follows: LGA1: first by +90 deg about +X, then by 180 deg about +Z LGA2: by +90 deg about +X LGA3: by -90 deg about +X LGA4: first by -90 deg about +X, then by 180 deg about +Z The frame definitions below implement these rotations. Since the SPICE frames subsystem calls for specifying the reverse transformation--going from the instrument or structure frame to the base frame--as compared to the description given above, the order of rotations assigned to the TKFRAME_*_AXES keyword is also reversed compared to the above text, and the signs associated with the rotation angles assigned to the TKFRAME_*_ANGLES keyword are the opposite from what is written in the above text. \begindata FRAME_SIRTF_LGA1_RX = -79510 FRAME_-79510_NAME = 'SIRTF_LGA1_RX' FRAME_-79510_CLASS = 4 FRAME_-79510_CLASS_ID = -79510 FRAME_-79510_CENTER = -79 TKFRAME_-79510_SPEC = 'ANGLES' TKFRAME_-79510_RELATIVE = 'SIRTF_SC_BUS' TKFRAME_-79510_ANGLES = ( -90.0, 0, 180.0 ) TKFRAME_-79510_AXES = ( 1, 2, 3 ) TKFRAME_-79510_UNITS = 'DEGREES' FRAME_SIRTF_LGA2_TX = -79520 FRAME_-79520_NAME = 'SIRTF_LGA2_TX' FRAME_-79520_CLASS = 4 FRAME_-79520_CLASS_ID = -79520 FRAME_-79520_CENTER = -79 TKFRAME_-79520_SPEC = 'ANGLES' TKFRAME_-79520_RELATIVE = 'SIRTF_SC_BUS' TKFRAME_-79520_ANGLES = ( -90.0, 0, 0 ) TKFRAME_-79520_AXES = ( 1, 2, 3 ) TKFRAME_-79520_UNITS = 'DEGREES' FRAME_SIRTF_LGA3_RX = -79530 FRAME_-79530_NAME = 'SIRTF_LGA3_RX' FRAME_-79530_CLASS = 4 FRAME_-79530_CLASS_ID = -79530 FRAME_-79530_CENTER = -79 TKFRAME_-79530_SPEC = 'ANGLES' TKFRAME_-79530_RELATIVE = 'SIRTF_SC_BUS' TKFRAME_-79530_ANGLES = ( 90.0, 0, 0 ) TKFRAME_-79530_AXES = ( 1, 2, 3 ) TKFRAME_-79530_UNITS = 'DEGREES' FRAME_SIRTF_LGA4_TX = -79540 FRAME_-79540_NAME = 'SIRTF_LGA4_TX' FRAME_-79540_CLASS = 4 FRAME_-79540_CLASS_ID = -79540 FRAME_-79540_CENTER = -79 TKFRAME_-79540_SPEC = 'ANGLES' TKFRAME_-79540_RELATIVE = 'SIRTF_SC_BUS' TKFRAME_-79540_ANGLES = ( 90.0, 0, 180.0 ) TKFRAME_-79540_AXES = ( 1, 2, 3 ) TKFRAME_-79540_UNITS = 'DEGREES' \begintext Combined LGA Pattern Frame -------------------------------------------------------- This diagram based on [4] illustrates the common LGA frame, called "coupled LGA frame", in which the combined pattern of all four LGA have been measured pre-launch. This frame is used operationally instead of the individual LGA frames. This frame is co-aligned with the spacecraft frame: Spacecraft +X side view: ------------------------ LGA2 LGA1 = = | |___| | || Solar array .' `. || .' .___. `.|| | +Xsc +Xlgac|| | | o------------> ------> | `._|_.' ||| +Zsc +Zlgac `. | .'|| `. _|_ .' || | | | | | || = | = V +Ysc | | +Ylgac | V Since the SPICE frames subsystem calls for specifying the reverse transformation--going from the instrument or structure frame to the base frame--as compared to the description given above, the order of rotations assigned to the TKFRAME_*_AXES keyword is also reversed compared to the above text, and the signs associated with the rotation angles assigned to the TKFRAME_*_ANGLES keyword are the opposite from what is written in the above text. \begindata FRAME_SIRTF_LGA_COUPLED = -79550 FRAME_-79550_NAME = 'SIRTF_LGA_COUPLED' FRAME_-79550_CLASS = 4 FRAME_-79550_CLASS_ID = -79550 FRAME_-79550_CENTER = -79 TKFRAME_-79550_SPEC = 'ANGLES' TKFRAME_-79550_RELATIVE = 'SIRTF_SC_BUS' TKFRAME_-79550_ANGLES = ( 0.0, 0.0, 0.0 ) TKFRAME_-79550_AXES = ( 1, 2, 3 ) TKFRAME_-79550_UNITS = 'DEGREES' \begintext SIRTF NAIF ID Codes Definition Section ======================================================================== This section contains name to NAIF ID mappings for the SIRTF mission. SIRTF spacecraft IDs: ------------------------------------------------------------- This table summarizes SIRTF Spacecraft IDs: Name ID Synonyms --------------------- ------- --------------------------------- SIRTF -79 SPACE INFRARED TELESCOPE FACILITY Name-ID Mapping keywords: \begindata NAIF_BODY_NAME += ( 'SIRTF' ) NAIF_BODY_CODE += ( -79 ) NAIF_BODY_NAME += ( 'SPACE INFRARED TELESCOPE FACILITY' ) NAIF_BODY_CODE += ( -79 ) \begintext SIRTF instrument IDs: ------------------------------------------------------------- TBD SIRTF Spacecraft Structures IDs ------------------------------------------------------------- This table summarizes SIRTF Spacecraft Structure IDs: Name ID Synonyms --------------------- ------- ------------------------- SIRTF_SPACECRAFT -79000 SIRTF_SC SIRTF_HGA -79500 SIRTF_LGA1_RX -79510 SIRTF_LGA2_TX -79520 SIRTF_LGA3_RX -79530 SIRTF_LGA4_TX -79540 Name-ID Mapping keywords: \begindata NAIF_BODY_NAME += ( 'SIRTF_SPACECRAFT' ) NAIF_BODY_CODE += ( -79000 ) NAIF_BODY_NAME += ( 'SIRTF_SC' ) NAIF_BODY_CODE += ( -79000 ) NAIF_BODY_NAME += ( 'SIRTF_HGA' ) NAIF_BODY_CODE += ( -79500 ) NAIF_BODY_NAME += ( 'SIRTF_LGA1_RX' ) NAIF_BODY_CODE += ( -79510 ) NAIF_BODY_NAME += ( 'SIRTF_LGA2_TX' ) NAIF_BODY_CODE += ( -79520 ) NAIF_BODY_NAME += ( 'SIRTF_LGA3_RX' ) NAIF_BODY_CODE += ( -79530 ) NAIF_BODY_NAME += ( 'SIRTF_LGA4_TX' ) NAIF_BODY_CODE += ( -79540 ) \begintext