Contents

• DSN utilization for radio astronomy research
• Radio astronomy observations conducted with the DSN
• Publications describing radio astronomy activities in the DSN

• Tables and Figures:
• Table 1 - Summary of statistics
• Table 2 - List  of  publications  sorted by the number of citations (only papers with more than 10 citations for years 1965 through 1998)
• Figure  1 - Antenna hours by year and program type
• Figure  2 - Proposals submitted by year
• Figure  3 - Publications by year
• Figure  4 - Publications by program and year
• Figure  5 - Publications by year in association with space missions
• Figures 6 -Institutional/Country association of scientists who performed the radio astronomy research with the DSN.

• Annual usage reports

1. DSN utilization for radio astronomy research

The history of the DSN antennas' utilization to support radio astronomy programs (number of hours at 64-70m and 34m subnets vs. years) is shown in Figure 1.

Major categories of  radio astronomy programs  supported by the DSN  include:

• Radio astronomy research programs authorized by the NASA Office of Space Science (Code S) or by the JPL director. These programs usually continue for many years and may include a few observing sessions during a year. Such long duration programs are neccessary to conduct radio astronomical surveys or to monitor evolution of a celestial phenomenon (e.g., Jupiter radio emission). They include:
• Interstellar Microwave Spectroscopy and Planetary RadioAstronomy programs which were established in late '70s and are currently still active.
• VLBI programs to measure astrometric positions of the Southern Hemisphere radio sources (1980-91) and radio emitting stars (Radio Stars, continued since 1996).
• VLBI programs in conjunction with the space missions such as 1) ALSEP-VLBI astrometry of the APOLLO LUNAR SURFACE EXPERIMENTS PACKAGE,1976-81, 2) Radio-Optical Reference Frame Tie (in conjunction with the HIPPARCOS mission), 1987-95, and 3) Space VLBI co-observing (in conjunction with the VSOP mission), continued since 1997.
• DSN Guest observations.  NASA/JPL recognizes the great value of the DSN telescopes for radio astronomy and makes them available to Guest Observers -- non-JPL scientists who are undertaking radio astronomy research. Such Guest observations have been conducted at the DSN since the mid- 1960s. Proposals for  DSN Guest observations are peer reviewed by an independent committee consisting of  non-NASA/JPL scientists. The Radio Astronomy Selection (RAES) panel was established in late 1970s and  operated through the 1980s to review the proposals for the DSN. Because the majority of experiments requesting support by the DSN are the VLBI type, since the early 1990s  DSN VLBI proposals have been evaluated by the NRAO (USA), EVN(Europe) and ATNF (Australia) Program Committees. Other types of astronomical investigations (single-dish microwave or continuum) may be proposed directly to the TMOD/DSN Science Office manager, who will obtain outside peer review. A typical DSN Guest experiment consists of one or two observing sessions.
• Other institutions programs. With NASA authorization, DSN facilities can be used by non-JPL institutions to conduct radio astronomy observations. This category of  DSN radio astronomy research  includes:
• Host Country. In the intergovernmental treaties between the United States, Spain and Australia for operating the overseas DSN complexes, a provision is made for the host country scientists to use the DSN facility in that country for independent scientific activities on a non-interference basis. Additionally, between 1990 and 2000 the CSIRO (Australia) had access to the Canberra DSN facilities for radio astronomy purposes in exchange for the use of the Parkes telescope by the DSN. The Host Country observing time at the DSN facilities is allocated by the designated host country institutions (CSIRO in Australia, LAEFF in Spain).
• Crustal Dynamics (later known as Space Geodesy and CORE) VLBI geodesy program is run with the use of the DSN facilities under auspices of the Goddard Space Flight Center since the early 1980s.
• Another GSFC VLBI astrometry program in support of the Gravity Probe-B space mission has been conducted with the participation of the DSN facilities since the mid-1990s.

2. Radio astronomy observations conducted with the DSN

The DSN facilities have been used for a wide range of radio astronomy experiments employing major radio astronomy techniques: radiometry, spectroscopy and interferometry. The distribution of peer reviewed proposals for radio astronomy observations with the DSN is shown in Figure 2. The proposals are divided into three categories by the type of radio astronomy techniques employed:
1) Very Long Baseline Interferometry (VLBI), 2) Microwave Spectroscopy on a single telescope (e.g. OH and H2O maser  radio emission) and 3) Continuum Single Dish (e.g., observations of the continuum sources variability, pulsars and scintillations due to random refraction in the interplanetary and interstellar mediums).

Note that VLBI observations at the DSN in most cases are conducted in conjunction with the world-wide distributed network of VLBI radio telescopes. Despite the difficulties of the schedule coordination with other telescopes, the VLBI is the most popular type of observation requested by DSN science guest users.

3.  Publications describing radio astronomy activities in the DSN

The history of publications related to the radio astronomy research with the DSN is depicted in Figure 3. The full list of Publications can be accessed
year by year from Table 1. Table 2 provides the list  of  publications  sorted by the number of citations (only papers with more than 10 citations for years 1965 through 1998).

Figure 4 shows the distribution of the number of publications sorted by 1) four categories based on observing techniques and 2) publications on the radio astronomy instrumentation/techniques developed at the DSN. Notice the significant increase in the number of publications in 1999 and 2000. These publications contain the results of the SVLBI mission, VSOP, which was supported by the DSN 11m subnet dedicated to  SVLBI spacecraft tracking (and, hence, can be considered as  part of the space radio telescope) and by the 70m DSN co-observing telescopes.

The DSN is the NASA facility dedicated to  tracking spacecraft and space research. Hence, an important part of radio astronomy research at the DSN is conducted in conjunction with space projects.  Figure 5 depicts the distribution  of publications using the results of this research. (Note that the contribution of the VSOP experiments supported by the 70m DSN is shown separately).

The DSN is used widely by the international radio astronomy community. Figures 6 show Institutional/Country association of scientists who performed the radio astronomy research with the DSN.
 

The page is maintained by Judy Hoeptner.

Please address the questions related to the
content of this page  to:

Judy Hoeptner (judith.hoeptner@jpl.nasa.gov)
or
Valery Altunin (Valery.I.Altunin@jpl.nasa.gov)