Equipment Summary

ARO Equipment Summary and Status

12M Telescope (EIE ALMA Protoype Antenna) - Kitt Peak

July 30 2019

  • 12 Meter Diameter; f/8
  • Observing season: October - June
  • Carbon fiber construction
  • Altitude over Azimuth
  • Absolute pointing accuracy: 2.5” rms
  • Tracking precision: 0.2” rms
  • Efficiency: 85% +/- 5%
  • Azimuth range: +/-270°
  • Elevation range: 3° to 110°
    • Observational range: ~18° - 84°
  • Slew speed: 360° min-1
    • Observational value: 60° min-1 (Dome tracking limited)
  • Supports position-switching, beam-switching, on-the-fly mapping, and continuum observing

Front Ends

Multi - Band Receiver ( 4mm, 3mm, 2mm, 1mm, Dual polarization, SBS )

  • 3mm (ALMA Band 3; 84 – 116 GHz; Available)
    • Image Rejection: 15 dB minimum, ≥ 20 dB typical
    • Typical Tsys@90GHz = 120-160 K, Tsys@115GHz = 250-375 K
    • Best Tsys@90GHz = 85-110 K, Tsys@115GHz = 150-200 K
  • 4mm (66 – 90 GHz; Available, shared-risk)
  • 1mm (211 – 275 GHz; Available, shared-risk)
  • 2mm (In development)

Back Ends

ARO Wideband Spectrometer (AROWS)

  • Interim: two 4 GHz wide IFs (Available)
  • Final: four 4 GHz wide IFs (Unavailable)
Mode total bandwidth (MHz) Channel spacing (khz) velocity resolution at 86 GHz (km s-1) velocity resolution at 115 GHz (km s-1)
0 4000 625 4.4 3.2
1 2000 312.5 2.2 1.6
2 1000 156.25 1.1 0.8
3 500 78.125 0.54 0.40
4 250 39.0625 0.28 0.20
5 125 19.53 0.14 0.10

12 Meter MAC (2 IF Mode; Available)

  • Center frequency fixed at 6.3 GHz in receiver IF.
bandwidth (Mhz) channels usable (Mhz) usable channels △v* (khz) resolution (hkz)
800 2048 600 1536 390.6 781.2
800 4096 600 3072 195.3 390.6
400 4096 300 3072 97.6 195.3
400 8192 300 6144 48.8 97.6
200 8192 150 6144 24.4 48.8
200 16384 150 12288 12.2 24.4
100 16384 75 12288 6.1 12.2
100 32768 75 24576 3 6.1

*This is the frequency sampling interval, not the FWHM channel width.


Observing Restrictions

Sun Avoidance: The 12m requires a 10° Sun avoidance zone.

Observing: On-the-fly mapping is currently unavailable with the MAC back end.


Submillimeter Telescope (SMT) - Mt. Graham

July 30 2019

  • 10 Meter Diameter; bent Cassegrainl f/13.8
  • Observing season: October - June
  • Carbon fiber and invar steel construction
  • Altitude over Azimuth
  • Absolute pointing accuracy: 2” rms
  • Tracking precision: 0.2” rms
  • Efficiency: 71% +/- 5% at 216 and 228 GHz
  • Azimuth range: +/-270°
  • Elevation range: -2° to 91°
    • Observational range: ~20° - 84°
  • Slew speed: 60° min-1
  • Supports position-switching, beam-switching, on-the-fly mapping, and continuum observing

Front Ends

1.3mm Receiver (Available)

  • ALMA Band 6 (205 – 280 GHz)
  • Dual polarization, SBS
  • Typical Tsys@230GHz = 200-275 K
  • Best Tsys@230GHz = 130-160 K

0.4mm Receiver (Unvailable)

  • 602 – 720 GHz
  • Dual polarization, DSB
  • 80 K TRx

0.7mm Receiver (Unvailable)

  • 385 - 500 GHz
  • Dual polarization, SBS
  • 150 K TRx

0.8mm Receiver (Available)

  • 325 – 370 GHz
  • Dual polarization, DSB
  • Typical Tsys@345GHz = 600-900 K
  • Best Tsys@345GHz = 350-500 K

New 0.8mm Band 7 Receiver (In development)

  • ALMA Band 7 (275 – 373 GHz)
  • Dual polarization, SBS
 

Back Ends

SMT Filter banks (Available)

  • The SMT IF range is 4-8 GHz for all receivers except the 0.8mm receiver, which has an IF range of 4-6 GHz. The IF center frequency is tunable from 4.5-7.5 GHz.
mode bandwidth (MHz) resolution (khz)
1 IF 2000 1000
2 IF 1000 1000
2 IF 64 250
4 IF 512 1000
4 IF 32 250

Observing Restrictions

Sun Avoidance: The SMT requires a 45° Sun avoidance zone.

Observing: None.


Recently Fixed and Current Issues

12M Telescope (EIE ALMA Prototype Antenna) - Kitt Peak

MAC: Unusable for on-the-fly mapping due to hardware limitations.

 

Submillimeter Telescope (SMT) - Mt. Graham

Filters 1.0MHz: There are periods of instability in the IF down conversion stages that manifests itself in platforming. Problems appear worse in position-switching and on-the-fly observing modes.

Filters 250kHz: The instability noted in the 1.0 MHz filters also appears in these filters. This platforming step is located at the IF center frequency and can be avoided by offsetting the IF.

Position - switching mode: There is a standing wave present when using observing in position-switching mode, especially at the upper end of 1.3mm receiver observing band. This standing wave is not atmospherically induced but instead is related to the receiver/hardware.


For more information, please contact:
Dr. H. Alyson Ford, Manager, Radio Telescopes
alysonford@email.arizona.edu