Employees: 76 + ~5 students

Correlator group

• VLA correlator
• At VLA
• Lag-type: cross-multiply lags, then transform
• Real-time, 27 antennas, 351 baselines
• VLBA correlator
• At AOC
• FX-type: transform to frequency spectrum, then cross-multiply
• Record-time-synchronize playback of up to 20 antenna data tapes
• EVLA correlator implementation

Cryogenics group

• Cryo-coolers (15 Kelvin, -432F) for cooled front-ends of receivers, closed cycle
• Helium gas compressors
• Helium gas refrigerators
• Helium lines on antennas
• VLA waveguide (all data communication between antennas & control building)
• Nitrogen gas pressurization
• Rotary joints, 2 per antenna
• Site paging, civil clocks
• EVLA fiber optics support

Data Acquisition Group

• VLBA data-tape recorders, 2 at each of 11 stations
• VLBA tape playback drives, 24 at AOC correlator
• Formatters, Samplers
• EVLA fiber optics design

Front End Group

• VLA receiver front ends and frequency converters
• 6 cooled front ends per antenna
• 2 un-cooled front ends per antenna
• VLBA receiver front ends and frequency converters
• 8 cooled front ends per antenna
• 2 un-cooled front ends per antenna
• VLA waveguide testing, cathodic protection system maintenance supervision
• Atmospheric Phase interferometer (VLA)
• Water Vapor radiometer
• P & 4 band dipoles
• EVLA receiver design, feeds implementation
• RFI/EMC/frequency coordination

Field Group

• Ten VLBA stations, from Virgin Islands to Hawaii
• Two technicians at each station, one on-call at all times
• antenna maintenance
• electronics, computer, communications maintenance
• building & grounds, electrical generator maintenance
• data tape operations
• local public relations
• Projects such as: VLBA holography digital tach, pointing improvements, and web cam

Lab Services Group

• Computer Aided Drawing (CAD) & web services for division
• Circuit, module, & cable assembly for division Lab infrastructure
• EVLA hardware, power supplies, production

LO/IF group

• Systems to process and transmit reference & tunable frequencies (LO) and intermediate frequency bands (IF)
• Frequency standards ? hydrogen masers
• Time ? UTC and IAT +/- 0.2 micro seconds
• PT link
• EVLA LO/IF sampler design, VLA antenna phone commo/wye com

Monitor & Control Group

• Transmit between and interface to system hardware and control/monitor computer
• Servo Control systems for rotation and focus of antenna subreflectors
• Monitors of the antenna and receiver systems status /wye mom
• VLA & VLBA site weather stations
• Pulsar data acquisition systems
• EVLA M & C Design

Engineering Group

• EVLA, ALMA support, other projects