KPL/IK RPWI Instrument Kernel =============================================================================== This instrument kernel (I-kernel) contains the Radio and Plasma Wave Instrument (RPWI) sensors' parameters and structure locations definitions. It also provides an example to obtain the position of these strucutres. Version and Date ------------------------------------------------------------------------------- Version 0.3 -- December 8, 2022 -- Marc Costa Sitja, ESAC/ESA Added structures definitions, RPWI views, and a code example. Version 0.2 -- June 04, 2016 -- Marc Costa Sitja, ESAC/ESA Claudio Jose Munoz Crego, ESAC/ESA Updated all NAIF ID codes from -907* to -28* since the JUICE spacecraft NAIF ID has been updated from -907 to -28. Initial Release. Pending review by the RPWI instrument team. Version 0.1 -- May 12, 2016 -- Jorge Diaz del Rio, ODC Space Added instrument description. Version 0.0 -- April 26, 2016 -- Jorge Diaz del Rio, ODC Space Initial Release. Pending review by the RPWI instrument and JUICE Science Operations Working Group teams. References ------------------------------------------------------------------------------- 1. ``Kernel Pool Required Reading'' 2. ``C-kernel Required Reading'' 3. JUICE Frames Definition Kernel (FK), latest version. 4. ``JUICE - Jupiter Icy Moons Explorer. Exploring the emergence of habitable worlds around gas giants. Definition Study report,'' ESA/SRE(2014)1, September 2014 (JUICE Red book v1.0) 5. ``JUICE - JUpiter Icy Moons Explorer RPWI (Radio & Plasma Waves Investigation) Experiment Interface Document - Part B,'' JUICE-IRF-RPWI-EID-003, Issue 2.1, 16 June 2013 6. JUICE Mechanical Drawings and CAD model for external structures, July 2022. Contact Information ------------------------------------------------------------------------------- If you have any questions regarding this file contact the ESA SPICE Service (ESS) at ESAC: Alfredo Escalante Lopez (+34) 91-8131-429 spice@sciops.esa.int or the JUICE Science Operations Center at ESAC: Marc Costa Sitja (+34) 646-746-711 Marc.Costa@ext.esa.int Implementation Notes ------------------------------------------------------------------------------- This SPICE I-kernel defines not values for the the ``kernel pool'', it was created with, and can be updated with a text editor or word processor. Instrument Description and Overview ------------------------------------------------------------------------------- The Radio & Plasma Wave Investigation (RPWI) provides an set of electromagnetic fields and cold plasma instrumentation, where several different types of sensors will sample the thermal plasma, DC electric fields, electric and magnetic signals from radio, plasma waves and micrometeorite impacts, as well as monitoring the spacecraft potential and integrated EUV flux (see [4] and [5]). RPWI is a versatile instrument for in situ investigations of the highly dynamic and, in many respects, very different space plasma environments, which will be encountered by the JUICE spacecraft around Jupiter's icy moons and in Jupiter's magnetosphere. To this end, RPWI makes use of several different sensors and receivers. Altogether, the instrument uses 10 sensors and 3 receivers, which cover a wide frequency range, from DC up to 45 MHz. There are 4 Langmuir probes (LP-PWI) for plasma and electric field measurements, a search coil magnetometer (SCM) with 3 coils for magnetic fields measurement, and 3 radio antennas (RWI). Thus, the RPWI sensors provide complete measurements of the electric and magnetic field vectors. This makes it possible to unambigously measure true physical observables, such as the energy flux (Poynting vector) and the wave polarization. The radio antennas provide remote sensing capabilities to RPWI, including the possibility to perform polarimetry and direction finding of coherent (non-thermal) radio emissions. The functional description of the RPWI system is most conveniently described in terms of its three different experiments, GANDALF, MIME, and JENRAGE (see [5] for further details): - GANDALF (GANymede plasma Density And Low-Frequency wave instrument): - LP-PWI (Langmuir Probe - Plasma Wave Instrument) - SCM (SearchCoil Magnetometer) - LP receiver - LF receiver - MIME (Mutual IMpedance Experiment) - LP-PWI - RWI (Radio Wave Instrument) - LP receiver - HF receiver - JENRAGE (Jupiter ENvironment Radio Astronomy and Ganymede Exploration) - RWI antenna - HF receiver GANDALF makes use of four spherical Langmuir probes (LP-PWI), 10 cm in diameter, mounted on separate 3 metre long deployable booms. The probes can be operated in two different modes: - current sampling mode (used as Langmuir probes) or; - voltage sampling mode (used as electric field probes). The LP and LF receivers are the main receivers for the LP-PWI probes. The Search Coil Magnetometer (SCM), which will be mounted on the J-MAG boom, is connected directly to the LF receiver. In addition, the probes serve the MIME experiment, which use them for transmission and reception for frequencies up to 1.47 MHz. For higher frequencies (up to 3 MHz), the probes are used for tramsission and the RWI antenna for reception. The MIME drivers are then synchronized to the frequency of the HF receiver. The functionality of the MIME subsystem is that of a laboratory network analyzer, which is an advanced Ohm-meter used to measure the frequency dependent complex impedance of an unknown device or medium. The medium, in this case the space plasma, is stimulated by a sinusoidal signal, which is and transmitted by one pair of Langmuir probes and received by the other pair. During normal operations in the HF range (above 1.47 MHz up to 45 MHz) the RWI antennas will be used for reception. JENRAGE makes use of three 2.5 meter long mutually perpendicular radio antennas (RWI) to measure three components of the high-frequency electric field in the 0.08 - 45 MHz range. The main characteristics of RPWI sensors are provided in the following table: LP-PWI: -------------------------------------------------------------------- PARAMETER VALUE ------------------------------ ----------------------------------- Frequency band DC- 1.47 MHz Sensitivity (DC E-field) 1 mV/m (1) Sensitivity (AC E-field) 10 nV/m/Hz-1/2 @ 1MHz Density range (Electrons) 10-4 to 10+5 Density range (Ions) 1 to 10+5 Temperature range (Electron) 0.02 - 30 eV Temperature range (Ion) 0.02 - 20 eV Probe bias voltage -100 to +100 V Probe bias current -100 to +100 nA Input impedance >10+12 (E-field); <100 (Density) -------------------------------------------------------------------- (1) Error @ DC: <7 mV/m (in Jupiter's magnetosphere) <1 mV/m near icy moons LP-Receiver: -------------------------------------------------------------------- PARAMETER VALUE ------------------------------ ----------------------------------- Frequency band DC-1.47 MHz (E-field) DC-10 kHz (Density) Max E-field amplitude +/-0.5 V/m Dynamic range >100 dB (E-field) >120 dB (Density) -------------------------------------------------------------------- LF-Receiver: -------------------------------------------------------------------- PARAMETER VALUE ------------------------------ ----------------------------------- Frequency band 0.1 - 20000 Hz Maximum AC M-field amplitude 5 nT Maximum E-field amplitude 1 V/m Dynamic range >70 dB Input impedance >5000 Ohm -------------------------------------------------------------------- RWI: -------------------------------------------------------------------- PARAMETER VALUE ------------------------------ ----------------------------------- Frequency band 0.08 - 45 MHz Sensitivity 2 to 3 nV/Hz1/2 @ 10MHz 10 nV/Hz1/2 @ 10MHz (2) Gain 20 dB Cross-talk <-40 dB 2nd harmonic distortion <-40 dB Input swing 0.12 V (Peak-to-peak) Output swing 1.2 V (Peak-to-peak) Output impedance 50 Ohm Ripple 20 mV (3) -------------------------------------------------------------------- (2) Including antenna gain. (3) Peak-to-peak, within the working frequency band. SCM: -------------------------------------------------------------------- PARAMETER VALUE ------------------------------ ----------------------------------- Frequency band 0.1 - 20000 Hz Sensitivity 4 fT.Hz-1/2 @ 4kHz Scale factor 100 mV/nT Output swing 6 V (4) Output impedance >1 kOhm Ripple 0.1mV (5) -------------------------------------------------------------------- (4) 50nT peak-to-peak @ Full Scale. (5) Peak-to-peak within the working frequency band. MIME: -------------------------------------------------------------------- PARAMETER VALUE ------------------------------ ----------------------------------- Frequency band (LP/LP mode) 1-1470 kHz Frequency band (LP/RWI mode) 80-3000 kHz Density range 0.01-10000 particles/cm3 Temperature range 0.01-100 eV Density resolution <5% Temperature resolution <15% Data Acquisition 1 spectra/min (Survey mode) 8 spectra/min (Burst mode) Emission signal 2 V (6) Output impedance ~10+6 Ohm -------------------------------------------------------------------- (6) Peak-to-peak @ Full Scale; Depending on the distance between transmission probes and reception probes Mounting Alignment ------------------------------------------------------------------------------- Refer to the latest version of the JUICE Frames Definition Kernel (FK) [3] for the RPWI reference frame definitions and mounting alignment information. RPWI structure location specification ------------------------------------------------------------------------------- The following table lists the name, center, and position for each of the structures/sensors available for RPWI, providing the reference frame used for their specification and the center to which they are referenced. Structure/Sensor Center X,mm Y,mm Z,mm ------------------ --------------- ------- ------- ------- JUICE_RPWI_RWI JUICE_MAG_BOOM 8573.3 0.0 0.0 (1) JUICE_RPWI_RWI_EX JUICE_RPWI_RWI -22.0 -15.2 186.2 (1) JUICE_RPWI_RWI_EX_P JUICE_RPWI_RWI 1091.7 334.3 653.9 (1) JUICE_RPWI_RWI_EX_M JUICE_RPWI_RWI -1135.7 -364.7 -281.6 (1) JUICE_RPWI_RWI_EY JUICE_RPWI_RWI 67.2 31.2 145.6 (1) JUICE_RPWI_RWI_EY_P JUICE_RPWI_RWI -402.9 1165.4 417.2 (1) JUICE_RPWI_RWI_EY_M JUICE_RPWI_RWI 537.2 -1103.1 -126.0 (1) JUICE_RPWI_RWI_EZ JUICE_RPWI_RWI -29.2 79.3 133.5 (1) JUICE_RPWI_RWI_EZ_P JUICE_RPWI_RWI -375.6 -336.2 1268.7 (1) JUICE_RPWI_RWI_EZ_M JUICE_RPWI_RWI 317.2 494.7 -1001.8 (1) JUICE_RPWI_SCM JUICE_MAG_BOOM 8201.3 0.0 0.0 (1) JUICE_RPWI_SCM_EX JUICE_RPWI_SCM 14.6 72.6 128.3 (1) JUICE_RPWI_SCM_EX_P JUICE_RPWI_SCM 14.6 -29.0 119.0 (1) JUICE_RPWI_SCM_EX_M JUICE_RPWI_SCM 14.6 174.2 137.7 (1) JUICE_RPWI_SCM_EY JUICE_RPWI_SCM -15.4 118.1 90.6 (1) JUICE_RPWI_SCM_EY_P JUICE_RPWI_SCM -15.4 109.2 192.2 (1) JUICE_RPWI_SCM_EY_M JUICE_RPWI_SCM -15.4 127.0 -11.0 (1) JUICE_RPWI_SCM_EZ JUICE_RPWI_SCM -0.4 82.5 94.4 (1) JUICE_RPWI_SCM_EZ_P JUICE_RPWI_SCM -102.4 82.5 94.4 (1) JUICE_RPWI_SCM_EZ_M JUICE_RPWI_SCM 101.6 82.5 94.4 (1) JUICE_RPWI_LPB1 JUICE_SPACECRAFT 1383.8 1134.2 2280.9 JUICE_RPWI_LP1 JUICE_RPWI_LPB1 2950.0 14.3 0.0 (2) JUICE_RPWI_LPB2 JUICE_SPACECRAFT 1455.0 -1162.3 3207.3 JUICE_RPWI_LP2 JUICE_RPWI_LPB2 2950.0 14.3 0.0 (2) JUICE_RPWI_LPB3 JUICE_SPACECRAFT 1455.0 -1162.3 246.8 JUICE_RPWI_LP3 JUICE_RPWI_LPB3 2950.0 14.3 0.0 (2) JUICE_RPWI_LPB4 JUICE_SPACECRAFT -1378.5 1143.4 2335.7 JUICE_RPWI_LP4 JUICE_RPWI_LPB4 2950.0 14.3 0.0 (2) (1) The value provided in this table is the one that corresponds with the fully deployed boom (note that the boom is folded in three pieces when stowed). See [6] for further details. (2) As stated in [6], the Langmuir Probe booms are 3 meters in length, including the Langmuir probes, which are 10 centimeters in diameter. The center of the Langmuir probe is considered the center of mass of the sensor. The value provided in this table is the one for the fully deployed boom (note that the boom is folded in two pieces when stowed). See [6] for further details. Magnetometer Boom (MAG Boom) Diagram ------------------------------------------------------------------------ The following diagrams show the location of each sensor on the Magnetometer boom and the approximate location of the boom in the spacecraft bus. -Z Magnetometer Boom side view: ------------------------------- .---. | | ------- | | J-MAG Scalar ^ | | Magnetometer | '---' (MAGSCA) | | | | | | | ~~~ ~0.352m ~~~ | | | | | | | | | | .---. v | | ------- | | J-MAG Outboard Sensor ^ | | (MAGOBS) | '---' | | | | | | | ~~~ ~1.496m ~~~ | | | | | | | | | SCM sensor v .---.| | (RPWI_SCM) ------- ========| |||========== ^ ==========| |==|======= | | |.. | | | | | | | ~~~ | ~ ~~~ ~ ~0.413m \ | | / | \ | | / | \ | | / | \ | | / | \ | |/ v ` . \| | RWI sensor ------- ` .| | (RPWI_RWI) ^ / |`. | / | |\ ` . | / | | \ ` . | / ~~~ \ ` . | ~ ~~~ ~ | | | ~1.083m | | | | | | | | | | | | .---. v | | ------- | | J-MAG Inboard Sensor ^ | | (MAGIBS) | '---' | | | | | | | ~~~ ~7.285m ~~~ | | | | | | | |^ +Xmagb | ||| | ||| v ||| +Ymagb ------- x--------> +Zmagb +Zmagb is into the page RWI and SCM Dipoles Diagram ------------------------------------------------------------------------ The following diagram show the location of each of the RWI and SCM dipoles tips within each of the corresponding dipoles. -Z Magnetometer boom side view: ------------------------------- rwi_ex_p ~~~ ~ | | / | |+Xrwi rwi_ey_m | | ^ rwi_ez_m ~ | | / _~ ` < | |/ _.' +Zrwi` . | | _.' ` .=x|.' +Yrwi ` . _.'/ | | ` . _.' / | | ` . ~' / ~~~ ` ~ rwi_ez_p ~ ~~~ rwi_ey_p rwi_ex_m | | | | rwi_ez_p| | ~ | | MAG boom | | | | . | SCM sensor rwi_ex_m ~========| | |=========~ rwi_ex_p rwi_ey_m ~=========| |==========~ rwi_ey_p <----------o-----------> +Xscm | || +Yscm | ||| | ||| ~ ||| rwi_ez_m |v +Zscm | | ~~~ | | |^ +Xmagb ||| ||| ||| +Ymagb x--------> +Zmagb Langmuir Probe Booms (LPx Boom) Diagram ------------------------------------------------------------------------ The following diagrams show the location of each of the Langmuir Probe booms' reference holes and the position of the Langmuir Probe within each the corresponding boom. For the orientation of each of the booms, please refer to [7]. +Z s/c side view: ----------------- direction of flight ___________ HGA <--------------> \ / \ .--`.-----.'--.# LPB1 \ / | | / \ | | \ / | +Zsc +Ysc / \=>o<===============>o-| o------->o<===============>o<=\ / -Y Solar Array | | | +Y Solar Array / \ | | | \ / LPB2 #.___|__|______. / \ # | # LPB4 \ LPB3 V +Xsc +Xswi_base +Zsc is out of the page. #LPBx indicates the location of the Langmuir Probe Boom's reference hole in the boom's mounting plane for boom number x. +X Langmuir Probe side view: ---------------------------- | v ------ .---. Langmuir Probe 10 / \ cm | | ------ '...' --- ^ \\ \ | \\ \ \\ \ \\ \ ~~ ~2.95m ~~ \ +Ylpb^ \ \\ \ ^ +Zlpb-h \\ \| ~45deg .-\\ | ,' \\.|\ . .--\|--. +Ylpb-h //-----------------'--.o------->--------// .' Langmuir Probe .' deployment plane (*) +Zlpb .' <' +Xlpb-h and +Xlpb are out of the page. (*) Note that the LP deployment plane is the one defined by the movement of the boom while being deployed from its stowed configuration. IK Code Example --------------------------------------------------------------------------- This section contains an example code, in Python, illustrating how the position of the RPWI sensors can be retrieved using appropriate SPICE routine. The examples presented as stand-alone functions, ready to be cut-n-paste and called from an application by simply replacing . import spiceypy # Load the appropriate Meta-kernel. spiceypy.furnsh() def get_position(utc, origin, body): '''Get the position of a Body with respect to another at a given time. ''' # Convert the UTC time to epehmeris time. et = spiceypy.utc2et(utc) # Get the position of the target body with respect to the origin. pos, lt = spiceypy.spkpos(origin, et, origin, 'NONE', body) # Calculate the distance. dist = spiceypy.vnorm(pos) # Print the distance with an appropriate format. print(f"{body}{' '*(20-len(body))} {origin}\ {' '*(18-len(origin))} {dist*1000:.3f}") # Return the distance and position vector in meters. return dist*1000, pos*1000 # Obtain all the NAIF body names. body_names = spiceypy.gcpool('NAIF_BODY_NAME', 0, 10000, 80) # Print the header of the table that will provide the information. print(f"Body{' '*16} Origin {' '*11} Distance (m)") print(f"{'='*52}") # For the RPWI bodies, get the position WRT to the JUICE Mechanical # Center. for body_name in body_names: if 'JUICE_RPWI' in body_name: get_position('2034-01-01', 'JUICE_SPACECRAFT', body_name) # Print some extra position of bodies with respect to other bodies. print("") get_position('2034-01-01', 'JUICE_RPWI_SCM_EX', 'JUICE_RPWI_SCM_EX_P') get_position('2034-01-01', 'JUICE_RPWI_SCM_EX', 'JUICE_RPWI_SCM_EX_M') Executing this code yields a result similar to: Body Origin Distance (m) ==================================================== JUICE_RPWI_LPB1 JUICE_SPACECRAFT 2.899 JUICE_RPWI_LP1 JUICE_SPACECRAFT 5.806 JUICE_RPWI_LPB2 JUICE_SPACECRAFT 3.709 JUICE_RPWI_LP2 JUICE_SPACECRAFT 6.382 JUICE_RPWI_LPB3 JUICE_SPACECRAFT 1.879 JUICE_RPWI_LP3 JUICE_SPACECRAFT 4.003 JUICE_RPWI_LPB4 JUICE_SPACECRAFT 2.943 JUICE_RPWI_LP4 JUICE_SPACECRAFT 5.875 JUICE_RPWI_RWI JUICE_SPACECRAFT 9.424 JUICE_RPWI_RWI_EX JUICE_SPACECRAFT 9.380 JUICE_RPWI_RWI_EX_P JUICE_SPACECRAFT 10.484 (...) JUICE_RPWI_SCM_EX_P JUICE_RPWI_SCM_EX 0.102 JUICE_RPWI_SCM_EX_M JUICE_RPWI_SCM_EX 0.102 JUICE_RPWI_LP2 JUICE_RPWI_LP1 6.287 JUICE_RPWI_LP3 JUICE_RPWI_LP1 8.800 JUICE_RPWI_LP4 JUICE_RPWI_LP1 5.256 End of IK file.