Status Report of the WBD Experiment for the CAA Operations Review Board 20 May 2008 Jolene S. Pickett, Joanne M. Seeberger, and Ivar W. Christopher Department of Physics and Astronomy The University of Iowa Iowa City, IA, USA Contents 1. Introduction 2. Status of the instrument data products delivery 3. Status of the instrument calibration and cross-calibration activity 4. Status of software development: status and delivery to the CAA 5. Status of documentation delivery 6. Overview of the archiving activity for the extension 7. Open issues, problems 8. Summary Acknowledgments: NASA/Goddard Space Flight Center

OVERVIEW OF THE WBD INSTRUMENT AND DATA CHAIN 1. Introduction - 1 OVERVIEW OF THE WBD INSTRUMENT AND DATA CHAIN Transmit to Ground (220 kbits/s) * WBD INSTRUMENT Make waveform measurement using appropriate mode for region Antenna Bandwidth Ez 9.5 kHz Ey 19 kHz Bx 77 kHz By Conversion Freq. Resolution 0 kHz (Baseband) 8 bits 125.454 kHz 4 bits 250.908 kHz 1 bit 501.816 kHz Input Wave DSN or Panska Ves Receive and record data ftp transfer The University of Iowa Level 1 Processing Creation of L1 files Validation of L1 files Write L1 files to DVD * NOTE: WBD data have never been recorded onboard with one exception: March 7, 2001 in the WBD burst mode Mail DVDs Local Institute Analyze waveform Or convert to frequency domain for spectral analysis (FFT, wavelet, etc.) Extract L1 data French, Swedish and UK Cluster Data Centers, Stanford University, SwRI

Example of Chorus Waveforms from 3 spacecraft 1. Introduction - 2 Example of Chorus Waveforms from 3 spacecraft WBD is best suited for detailed analysis of the fine structure of linear and nonlinear waves observed throughout the orbit in support of: - Wave Experiment Consortium (WEC) objectives and complementary to the WHISPER and STAFF-SA instruments - WBD-specific objectives such as Very Long Baseline Interferometry (VLBI) and cross-spacecraft waveform correlation

1. Introduction - 3 Summary of the status of the archive for WBD at the CAA: Documentation: Archiving completed, except for updates of some time listings on a best efforts basis Software: Archiving completed Data: Overview spectrograms: Archiving completed for first four years of mission (1 Feb. 2001 – 31 Jan. 2005) High resolution spectrograms: Archiving completed for first four years of mission

1. Introduction - 4 Management at Iowa: Science: Jolene Pickett, WBD Principal Investigator (pickett@uiowa.edu) Ivar Christopher, WBD Operations Manager (ivar-christopher@uiowa.edu) Technical: Joanne Seeberger, WBD Data Manager (joanne-seeberger@uiowa.edu) Administrative: Robert Neppl (robert-neppl@uiowa.edu)

1. Introduction – 5 Action Items from OR-2 Review (May, 2006): R41: We recommend that the digital data be made available to the CAA. The WBD team should discuss with the CAA the best way to provide this data. Numerous conversations took place between the CAA, Iowa and Goddard Space Flight Center in January and February 2008 regarding the best way to provide the WBD data set to the CAA, should augmentation funding be received by Iowa to carry out the archiving, given its enormous size already (several TBytes). It was decided as a minimum to produce cdf files of the digital time series data for archival at the US Cluster Data Center (CDAWeb) and either transfer these files to the CAA for conversion to cef format or create cef files at Iowa or CDAWeb using the cdf files and transfer the cef files to the CAA. This action item should be closed.

1. Introduction - 6 Action Items from OR-2 Review (May, 2006) (cont.): R42:We note that there will be a NASA Senior Review in February 2008. We recommend that support is requested from NASA for US instrument teams, including WBD, to provide data to the CAA. ESA and the board would provide their full support to such a bid. The Cluster NASA Senior Review proposal was submitted to NASA on 21 Feb. 2008 and presented to the Senior Review Board on 8 Apr. 2008. The proposal contained a request for augmentation funding for Iowa to create WBD digital data files in cdf format for archival at the Cluster US Data Center (CDAWeb) and for either Iowa or CDAWeb to transfer the cdf files to the CAA for conversion to cef, or for Iowa to convert the cdf files to cef and deliver the cef files to the CAA. This action item should be closed with respect to WBD.

2. Status of the Instrument Data Products Delivery - 1 Two types of WBD data plots are already archived at the CAA: Overview Spectrograms Variable length (~0.5-6 hours) Multi-panel (one panel for each spacecraft for which there are WBD data) Postscript and png formats available High resolution Spectrograms 30-seconds in length Single spacecraft Instrument mode data contained at top of plot Gif format

2. Status of the Instrument Data Products Delivery - 2 OVERVIEW PLOTS Range from about 0.5 – 6 hours Show WBD spectral data (using FFT) from all spacecraft being sampled for the interval Used to identify events for in depth study Available as png files, e.g.: CM_CG_WBD_SPECPLOT_OVERVIEW_PNG_20020418_1036_V00.PNG Postscript versions made but not yet available CAA contains 1 Feb 2001 thru 31 Jan 2005

2. Status of the Instrument Data Products Delivery - 3 GIF PLOTS 30-second, full resolution Show spectral data (via FFT on ground) from only one spacecraft Top panels shows instrument mode Used to resolve fine structure of waves Available as gif files, e.g.: C4_CG_WBD_GIFPLOT__20020418_0910_20020418_0911_V00.gif CAA contains 1 Feb 2001 thru 31Jan 2005

3. Status of the Instrument Calibration and Cross-Calibration Activity - 1 WBD instruments are fully calibrated Calibration does not change over time Calibration is applied in the time domain and is thus frequency independent Iowa does not anticipate developing a frequency-dependent calibration because the filter response is nearly flat across the entire frequency bandpass (minor fall-off at edges of filters). Electric field calibration assumes a physical antenna length of 88 m, whereas the effective length may in fact be less than that in some regions. Units are mV/m Magnetic field calibration is in nT

3. Status of the Instrument Calibration and Cross-Calibration Activity - 2 Waveform cross-calibration previously carried out with EFW, which identified some timing, sign (of E-field) and receiver response issues which have been dealt with Power Spectral Density cross-calibration previously carried out with Whisper and STAFF with good agreement Currently working on cross calibration with PEACE of densities in low density regions (primarily below WHISPER cutoff frequency) WBD uses the wave L-X mode cutoff frequency to obtain the plasma frequency Densities for several time intervals from 2001-2006 have been compared to PEACE with mixed results – variations are still being investigated Will identify 2007 events soon and obtain densities

4. Software development: status and delivery to the CAA - 1 FIX_SC2.C C code to identify known bad data points in the time series, and then average across adjacent points (already delivered). Problem originates within the Onboard Data Handling System and was discovered from data obtained while the s/c was on the launch pad and thus not fixed. CALIBRATE.C C code to calibrate the WBD Level 1 data (already delivered). Calibration is applied in the time domain and is thus frequency independent.

4. Software development: status and delivery to the CAA - 2 EXAMPLES Directory (already delivered): EX_README.TXT Explanation of how to use the software CLOG.C Example C code to output a list of all data modes contained in a Level 1 file (if no mode changes, only one line is output) PARSETIME.C C code used to parse the data (needs to be linked to RD_WBD_WF.C) RD_WBD_WF.C Example C code to read the Level 1 data files and output the calibrated data in binary format WBDL1LIST.C Example C code to extract and list most fields contained in the Cluster WBD Level 1 file records WBDL1.H Contains macros, tables, etc. for use in processing Cluster WBD Level 1 data MAKEFILE Converts to Unix-friendly format, compiles the programs, runs the programs, and outputs data

4. Software development: status and delivery to the CAA - 3 EXAMPLES Directory (already delivered) (cont.): 03082749.9C1 Test Level 1 file WBDL1LIST03082749_9C1.TXT Output listing of all field values in file CLOG03082749_9C1.TXT Output listing of all data modes found R_WBD_WF0308271001.TXT Output Data File (waveform data only) Iowa does not anticipate archiving any further software at this time.

5. Status of WBD Documentation Delivery - 1 Documentation Already Delivered to CAA: General Documentation: WBD ICD Version 2.1 [pdf] WBD Data Coverage Files (listings of times and modes of WBD data availability, ~ 24 hours/week) [txt and html] Listing of times of Coordinated Cluster WBD/PEACE Chorus Operations [html] Listing of times of Coordinated Cluster WBD/WHISPER/PEACE Nonthermal Continuum Operations [html] Listing of times of Other Special Operations (HAARP, IMAGE RPI Transmissions, Mutual Impedance tests) [html] Cluster WBD Interpretation Issues [pdf] – see example next slide WBD Calibration [pdf]

5. Status of WBD Documentation Delivery - 2 Example from: Interpretation Issues document GAIN AMPLIFIER SWITCHING: 3 specific automatic gain state changes introduce: - ringing (artificial pulses) - intense broad bands in the waveforms in the frequency domain

5. Status of WBD Documentation Delivery - 3 Documentation Already Delivered to CAA (cont.): Documentation associated with and included on the WBD Level 1 DVDs: Instrument Description [txt] Description of the format of the Cluster WBD LEVEL1 data files [txt] Description of the contents of a Level 1 data DVD volume [txt] List of known problems and anomalies in the data [txt] Description of the origin of time stamps, their accuracies, and their preferred applications [txt]

5. Status of WBD Documentation Delivery - 4 Documentation still to be delivered (if funding received): Coverage Files for 2005 to present [txt and html] Updated Listing of Coordinated Cluster WBD/PEACE Chorus Operations (to include 2005-present) [html] Updated Listing of Coordinated Cluster WBD/WHISPER/PEACE Nonthermal Continuum Operations (to include 2005-present) [html] Updated Listing of Other Special Operations such as HAARP (2005-present) [html] Reference in connection with Interpretation Issues: “WBD Response to Bipolar and Tripolar Pulses: Bench Tests vs. in Flight Observations”, by J. M. Swanner, J. S. Pickett, J. R. Phillips, and D. L. Kirchner [pdf]

5. Status of WBD Documentation Delivery - 5 Sample from Coverage File: wbd_mop.jan_apr2002 Purpose: Used to determine if WBD data are available for a specified time and in the desired instrument mode START TIME STOP TIME S/C CONV. B/W ANT. RES. ================================================================= 2002-01-03T00:30:03.210Z 2002-01-03T02:40:38.383Z C4 0 kHz 9.5 kH Ez 8 bits 2002-01-03T00:30:58.546Z 2002-01-03T02:40:00.777Z C2 0 kHz 9.5 kH Ez 8 bits 2002-01-03T16:54:57.888Z 2002-01-03T17:55:12.163Z C2 0 kHz 9.5 kH Ez 8 bits 2002-01-03T16:55:04.359Z 2002-01-03T17:55:35.873Z C4 0 kHz 9.5 kH Ez 8 bits 2002-01-04T03:05:07.895Z 2002-01-04T05:40:12.657Z C3 0 kHz 9.5 kH Ez 8 bits 2002-01-04T03:46:03.334Z 2002-01-04T05:40:00.934Z C4 0 kHz 9.5 kH Ez 8 bits 2002-01-08T11:18:00.176Z 2002-01-08T12:52:32.591Z C4 0 kHz 9.5 kH Ez 8 bits 2002-01-08T11:42:37.387Z 2002-01-08T12:50:01.020Z C2 0 kHz 9.5 kH Ez 8 bits 2002-01-09T02:55:06.333Z 2002-01-09T05:00:00.845Z C4 0 kHz 77 kHz Ez 8 bits 2002-01-09T02:56:58.330Z 2002-01-09T05:00:48.179Z C2 0 kHz 77 kHz Ez 8 bits 2002-01-10T18:47:47.860Z 2002-01-10T18:49:20.484Z C4 250 kHz 9.5 kH Ez 8 bits 2002-01-10T18:49:20.524Z 2002-01-10T18:50:11.959Z C4 500 kHz 9.5 kH Ez 8 bits 2002-01-10T18:50:11.999Z 2002-01-10T18:51:08.677Z C4 125 kHz 9.5 kH Ez 8 bits 2002-01-10T18:51:08.717Z 2002-01-10T18:52:51.787Z C4 250 kHz 9.5 kH Ez 8 bits 2002-01-10T18:52:51.827Z 2002-01-10T18:53:43.262Z C4 500 kHz 9.5 kH Ez 8 bits =================================================================

6. Overview of the archiving activity for the extension -1 WBD will archive overview and high resolution plots plus data coverage and special event listings for 1 Feb. 2005 to present on a best efforts basis (or definitely if augmentation funding is received) If augmentation funding is received from NASA by Iowa, Iowa will: Create WBD digital data files in cdf format containing: Time tags (20 microsecond accuracy; ground-based and WEC-corrected onboard based), Instrument mode, Gain (needed for converting calibrated data back to data numbers 0-255), Calibrated time series data, Quality parameters, Sample rate (needed to convert to frequency domain), Two angles relating the measurement to the magnetic field direction and to an earth-sun based coordinate system.

6. Overview of the archiving activity for the extension - 2 If augmentation funding is received from NASA by Iowa, Iowa will (cont.): Archive the cdf files at CDAWeb (the site of the Cluster data center in the U.S.) Arrange for transfer of these cdf files to the CAA for conversion to cef format by the CAA, or create cef format files at Iowa to transfer to the CAA (details to be finalized if funding received) A sample one hour cdf file of Polar wideband data (similar to Cluster WBD) has recently been sent to the CAA for conversion to cef to check size and assess the viability of the process Even though only 20-40 hours of WBD data are received each week, due to the high bit rate of the data, there are already several TBytes of data.

7. Open issues and problems - 1 A small Living With a Star (LWS) grant was received by Iowa to archive the WBD documentation, software and first four years (1 Feb. 2001 – 31 Jan. 2005) of standard data plots. WBD has never been funded through its NASA Goddard Space Flight Center MO&DA grant to archive data, documentation and software at the CAA Augmentation funding to create cdf files of the entire WBD data set and archive them at CDAWeb was requested in the Cluster proposal that was submitted and presented to the NASA Senior Review Board on 8 April 2008 (still waiting for decision) If augmentation funding is received, Iowa will archive documentation and plots at the CAA from 2005 to present, as well as arrange for the times series data to be archived at the CAA.

7. Open issues and problems - 2 If augmentation funding is made available by NASA, the data delivery schedule will depend on the time needed to process and validate all existing data (> 7 TB for 2001-2007) and data taken during the rest of the mission Experience with the Polar wideband data suggests that a minimum of two years will be needed to complete the archiving of the cdf files for 2001-2007, with a third year to do 2008 and get up to date Assuming 1 Oct. 2008 as a reasonable start date for this activity, we propose the following schedule: Deliver all 2001-2007 data to the CAA by December 2010 Deliver the rest of the WBD data (through then most recently acquired data) by December 2011.

7. Open issues and problems - 3 Until the WBD time series is available in the CAA, all WBD data are available as follows (CAA should provide this information with links): Go to the WBD home page http://www-pw.physics.uiowa.edu/cluster/ and request a digital download from the “Data Analysis and Planning Tools” block on the left hand side of the page (ascii file only) – see next slide Download and use the software archived at the CAA and obtain the Level 1 data files from Iowa, SwRI or one of the WEC data centers in Europe Request calibrated data files from Iowa or SwRI Display and download overview and high resolution spectrograms for 1 Feb 2005 to present from the WBD web site – see next slide

7. Open issues and problems - 4 WBD Survey Plots Digital Data Download Tool

7. Open issues and problems - 5 Sample output file

8. Summary All of the documentation needed to understand the WBD data, all WBD software useful in reading and calibrating its Level 1 data files (which can be obtained at the WEC and US data centers), and overview and high resolution plots for the first four years of the mission have been archived and are available at the CAA Iowa firmly believes that the WBD digital time series data files, in standard CAA format, should be made available through the CAA and is attempting to obtain funds for that purpose through the NASA Senior Review process Until the WBD data are available in the CAA, we strongly encourage everyone to get them from one of the other sources previously mentioned and use them in their studies The WBD “Interpretation Issues” document should be downloaded from the CAA and consulted when carrying out research with WBD data

EXAMPLE 2: INTERPRETATION ISSUES AND CAVEATS EDI INTERFERENCE: Observed at constant characteristic frequencies and multiple harmonics associated with the EDI mode

EXAMPLE 3: INTERPRETATION ISSUES AND CAVEATS (cont.) BATTERY SUBSYSTEM INTERFERENCE: Observed at constant frequency around 65 kHz and harmonics in the electric data Battery Subsystem Interference

EXAMPLE 4: INTERPRETATION ISSUES AND CAVEATS (cont.) WEC DWP CLOCK INTERFERENCE: Observed at constant frequency around 900 Hz and harmonics in the magnetic data DWP Clock Interference

EXAMPLE 5: INTERPRETATION ISSUES AND CAVEATS (cont.) WHISPER SOUNDINGS: Ringing-type effects observed in the waveform; Intense broad bands in the frequency domain

EXAMPLE 6: INTERPRETATION ISSUES AND CAVEATS (cont.) CLIPPING (due to limit of 8 bits) AND RECEIVER SATURATION: Harmonics are instrumental as opposed to natural

EXAMPLE 7: INTERPRETATION ISSUES AND CAVEATS (cont.) INSTRUMENTAL EFFECTS: Believed to originate at the electric field booms in certain types of plasmas and are not natural

EXAMPLE 8: INTERPRETATION ISSUES AND CAVEATS (cont.) MULTI-POLE FILTER RESPONSE TO PULSES: Get distortion as pulse duration approaches the RC time constant of the filter system Result: Pulse duration (and thus frequency) are not accurately measured A document describing this will be submitted to the CAA Bipolar pulse in (345 us); bipolar pulse out Bipolar pulse in (1700 us); tripolar pulse out