The Ulysses dual-frequency radio subsystem was utilized by the Ulysses Solar Corona Experiment (SCE) to measure the electron content (column density) and its variations during the fourth solar conjunction (C4) of the Ulysses mission in the winter of 1995. In the nominal mode for radio-sounding observations [BIRDETAL1992A], both downlinks (S-band: f_s = 2.3 GHz; X-band: f_x = 8.4 GHz) are phase coherent with the uplink (S-band: f_u = 2.1 GHz). The dual-frequency radio-sounding technique exploits the dispersive nature of ionized media on the propagation of the two downlinks. The tiny Doppler shift due to plasma moving in and out of the ray path is greater at S-band than at the higher frequency X-band. Similarly, because the group velocity of waves propagating in ionized media is smaller for lower frequencies, the round-trip time of propagation for coded range signals between the spacecraft and the ground station will be longer at S-band than at X-band. The SCE data are obtained from the Radio Science Support group at JPL [ASMAR&RENZETTI1993; ASMARETAL1995]. There are basically two types of data: Ranging and Doppler (Frequency), recorded at the tracking sites of the NASA Deep Space Network (DSN) as a function of UT Ground Received Time [DSN810-5]. The raw data are delivered in special binary files called ATDFs (Archival Tracking Data Files), containing Ranging and Doppler data from the standard DSN tracking receivers. There are high time resolution Doppler data from special radio science receivers (so-called 'open loop' data) as well. These are in files called ODRs (Original Data Records). ATDFs are files of radiometric data produced by the Network Operations Control Center (NOCC) Navigation Subsystem (NAV). They are derived from Intermediate Data Records by NAV and contain all radiometric measurements received from the DSN station including signal levels (`AGC' = automatic gain control in dBm), antenna pointing angles, frequency (often referred to simply as `Doppler'), range, and residuals. Doppler data are often used to infer spacecraft radial motion relative to the tracking antenna. Data values in ATDFs are reported at rates no higher than 10 per second. For the Ulysses solar conjunction C4 the received frequencies at S-Band and X-band were recorded at a nominal sample time of one per second. Ranging data were recorded nominally at intervals of ca. 5 minutes. Each ATDF data record contains 117 parameters, stored in records of 288 bytes. The ATDF is described in section TRK-2-25 of the JPL Document 820-13 [DSN820-13]. The ranging data from the ATDFs have been analyzed for the solar conjunction C4 and a number of publications describe the results [PAETZOLDETAL1995; BIRDETAL1996; PAETZOLDETAL1996]. Results from the first Ulysses solar conjunction (C1) are also available [PAETZOLDETAL1992; BIRDETAL1994; WOOETAL1995A; WOOETAL1995B; WOO1996]. The Ulysses radio subsystem was utilized during the Jupiter encounter to measure the columnar electron density of the Io Plasma Torus [BIRDETAL1992B; BIRDETAL1993]. These data, together with all Ulysses results from the Jupiter encounter, are archived at the Planetary Data System (PDS). Data files have been generated which contain the Ranging data at various stages of processing. Stage #1 generally involves just stripping the Ranging data from the ATDFs. Stage #2 is used to 'clean' the data files by weeding out obviously bad data. Stage #3 is the step that produces a 'final data set', a table of the measured data plus physically relevant quantities as function of time. The following table gives an idea about the size and coverage of the Ranging data set from the solar conjunction C4: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Ulysses SCE Ranging data at First Solar Conjunction C4: Stage# start stop ascii size gzip size mo:dd:hh:mm mo:dd:hh:mm (kB) (kB) 1 02:22:20:01 03:14:14:07 480 75 2 02:23:05:01 03:14:14:06 398 63 3 02:23:05:06 03:14:14:06 145 33 All stage #3 ranging data during the Ulysses solar conjunction C4 from 7 August to 5 September 1991 have been provided to this archive in the RANGE_C4.TAB directory, the first few lines of which are as follows: year mo dd hh:mm:ss set no dss difrng econt 1995- 2-23T 5: 6:29.376Z 1 1 42 378 1512 1995- 2-23T 5:11:55.104Z 1 2 42 385 1540 1995- 2-23T 5:17:20.832Z 1 3 42 376 1504 1995- 2-23T 5:22:47.424Z 1 4 42 427 1708 1995- 2-23T 5:28:13.152Z 1 5 42 400 1600 1995- 2-23T 5:33:38.880Z 1 6 42 382 1528 1995- 2-23T 5:39: 4.608Z 1 7 42 392 1568 1995- 2-23T 5:44:31.200Z 1 8 42 416 1664 1995- 2-23T 5:49:56.928Z 1 9 42 384 1536 1995- 2-23T 5:55:22.656Z 1 10 42 391 1564 1995- 2-23T 6: 0:49.248Z 1 11 42 400 1600 1995- 2-23T 6: 6:14.976Z 1 12 42 406 1624 1995- 2-23T 6:11:40.704Z 1 13 42 411 1644 1995- 2-23T 6:17: 7.296Z 1 14 42 399 1596 1995- 2-23T 6:22:33.024Z 1 15 42 419 1676 where: year = 1995 mo = month of year dd = day of month hh:mm:ss = hours, minutes seconds (UT, ground received) set = running no. for each DSN tracking pass during C4 no = running no. for range measurement within each tracking pass dss = DSN station number difrng = differential range delay in `range units' (RU) [DSN810-5] econt = electron content in `hexems' [BIRDETAL1992A; BIRDETAL1994] note: difrng (RU) and econt (hexems) are given to the nearest respective unit. The estimated accuracy of a differential range measurement is of the order of 50 range units. REFERENCES ASMARETAL1995 Asmar, S.W., and R.G. Herrera, Radio Science Handbook, JPL D-7938 Volume 6, Jet Propulsion Laboratory, Pasadena, CA, 1995. ASMAR&RENZETTI1993 Asmar, S.W., and N.A. Renzetti, The Deep Space Network as an Instrument for Radio Science Research, Jet Propulsion Laboratory Publication 80-93, Rev. 1, 15 April 1993. BIRDETAL1992A Bird, M.K., S.W. Asmar, J.P. Brenkle, P. Edenhofer, M. Paetzold, and H. Volland, The coronal-sounding experiment, Astron. Astrophys. Supp. Ser. 92, 425-430, 1992a. BIRDETAL1992B Bird, M.K., S.W. Asmar, J.P. Brenkle, P. Edenhofer, O. Funke, M. Paetzold, and H. Volland, Ulysses radio occultation observations of the Io plasma torus during the Jupiter encounter, Science 257, 1531-1535, 1992b. BIRDETAL1993 Bird, M.K., S.W. Asmar, P. Edenhofer, O. Funke, M. Paetzold, and H. Volland, The structure of Jupiter's Io plasma torus inferred from Ulysses radio occultation observations, Planet. Space Sci. 41, 999-1010, 1993. BIRDETAL1994 Bird, M.K., H. Volland, M. Paetzold, P. Edenhofer, S,W, Asmar, and J.P. Brenkle, The coronal electron density distribution determined from dual-frequency ranging measurements during the 1991 solar conjunction of the {\sl Ulysses} spacecraft, Astrophys. J. 426, 373-381, 1994. BIRDETAL1996 Bird, M.K., M. Paetzold, M., P. Edenhofer, S.W. Asmar, and T.P. McElrath, Coronal radio sounding with Ulysses: solar wind electron density near 0.1 AU during the 1995 conjunction, Astron. Astrophys. (in press), 1996. DSN810-5 Deep Space Network / Flight Project Interface Design Book, Document 810-5, Jet Propulsion Laboratory, Pasadena, CA. DSN820-13 Deep Space Network System Requirements / Detailed Interface Design, Document 820-13, Jet Propulsion Laboratory, Pasadena, CA. PAETZOLDETAL1992 Paetzold, M., M.K. Bird, H. Volland, P. Edenhofer, S.W. Asmar, and J.P. Brenkle, Coronal sounding with Ulysses: Preliminary results from the first solar conjunction, in Solar Wind Seven, E. Marsch and R. Schwenn (eds.), Pergamon Press, Oxford, 237-240, 1992. PAETZOLDETAL1995 Paetzold, M., M.K. Bird, P. Edenhofer, S.W. Asmar, and T.P. McElrath, Dual-frequency radio sounding of the solar corona during the 1995 conjunction of the Ulysses spacecraft, Geophys. Res. Lett. 22, 3313-3316, 1995. PAETZOLDETAL1996 Paetzold, M., J. Karl, and M.K. Bird, Coronal radio sounding with Ulysses: Dual-frequency phase spectra in coronal holes and streamers, Astron. Astrophys. (in press), 1996. WOO1996 Woo, R., Detection of low-latitude plumes in the outer corona by Ulysses radio ranging measurements, Astrophys. J. 464, L95-L98, 1996. WOOETAL1995A Woo, R., J.W. Armstrong, M.K. Bird and M. Paetzold, Variation of fractional electron density fluctuations inside 40 R_s observed by Ulysses ranging measurements, Geophys. Res. Lett. 22, 329-332, 1995a. WOOETAL1995B Woo, R., J.W. Armstrong, M.K. Bird and M. Paetzold, Fine-scale filamentary structure in coronal streamers, Astrophys. J. 449, L91-L94, 1995b.