NRAO-GB Support for VSOP-2 Glen Langston National Radio Astronomy Observatory Green Bank, WV USA NRAO Goals Support Space VLBI Science Ground Tracking VLBI support Develop Systems for integration into future Ground Science systems Langston: VSOP-2 at Yebes 06

Langston: VSOP-2 at Yebes 06 NRAO GB 20m Proven Operation at 2 to 9 GHz Surface RMS .3mm Should be good at 40 GHz. Prime focus optics VLBI antenna Fast 2deg/second Langston: VSOP-2 at Yebes 06

Langston: VSOP-2 at Yebes 06 20m Link Budget Need to plan link for worst Case: rain, 300 K 37.5 GHz margin 8.3 dB 26.0 GHz margin 6.7 dB (Pointing error < at 26 GHz) Need model of phase stability noise contributions Ionosphere Troposphere Clock noise SNR of return Signal Station position Rx/IF un-modeled delay variations Langston: VSOP-2 at Yebes 06

Weather/Opacity vs frequency Opacity is similar (factor of 2) at 26 and 38 GHz GB has daily weather model Bad weather today…. Langston: VSOP-2 at Yebes 06

Weather/Opacity vs time Langston: VSOP-2 at Yebes 06

Langston: VSOP-2 at Yebes 06 Antenna Signal Path All Items JAXA/ISAS Feed NRAO Receiver NRAO/All Satellite Sim. JAXA/Custom Transmitter Commercial Timing Tone Custom/Commercial Phase Measurement Custom/Commercial Demodulator Digital Custom/Commercial Decoder Custom/Commercial/Software Recorder Mk V/Commercial Data Extraction NRAO/Custom Monitor Custom Schedule Custom Langston: VSOP-2 at Yebes 06

NRAO Contributions/Interests $$$ Antenna $$ Software $ Low Noise Front Ends $ Uplink/Downlink phase control/detection $ Software Back Ends (real-time spectra/calibration of VSOP-2 data) Test correlation Transient Searches Continuum imaging Galactic molecules Langston: VSOP-2 at Yebes 06

Langston: VSOP-2 at Yebes 06 Costs $$$ Antenna $$ Design Engineer $$ Software $ Individual Modules (but these add up…) Langston: VSOP-2 at Yebes 06

Langston: VSOP-2 at Yebes 06 Conclusions The NRAO in GB Supports the Science Goals of the VSOP-2 Mission. GB will support GBT Science Observations of successful proposals. The NRAO in GB is willing to support VSOP-2 Ground Tracking. NRAO’s top ground tracking priority Develop technology and software for spacecraft tracking that has applications for GB science operations. Langston: VSOP-2 at Yebes 06

Ionospheric Incoherent Scatter First light detection of bistatic incoherent scatter from the F region ionosphere on a Millstone Hill to NRAO Green Bank forward path on 25 January 2006, at the common volume intersection point in geodetic coordinates: (40 deg lat, 283 deg lon, 300 km altitude). The upper data was collected using the reference Millstone Hill software radar platform in a monostatic configuration, while the lower data was collected on the MIDASMobile #001 platform at NRAO Green Bank. An uncoded 480 usec pulse was transmitted from Millstone Hill, resulting in a predicted and subsequently observed bistatic signal to noise ratio of 21 dB. Although the bistatic return appears to be approximately 80 km long in range, the actual ionospheric altitude resolution (set by common intersection volume size) is 10 km. Langston: VSOP-2 at Yebes 06

Molecule/Transient Survey Technology has advanced. Digital Spectra Pulsars and Transients in 1 backend Transients at 43GHz High Stability Molecule Survey All Sky coverage Langston: VSOP-2 at Yebes 06

Recent Test Data Obtained Langston: VSOP-2 at Yebes 06

Langston: VSOP-2 at Yebes 06 Bi-Static Radar Langston: VSOP-2 at Yebes 06

Langston: VSOP-2 at Yebes 06 GBT Operation at 0.3 to 49 GHz Dedicated participation High Sensitivity Array VLBI Langston: VSOP-2 at Yebes 06