The Very Long Baseline Array (VLBA) is a system of ten radio telescopes which are operated remotely from their Array Operations Center located in Socorro, New Mexico, as a part of the National Radio Astronomy Observatory (NRAO). These ten radio antennas work together as an array that forms the longest system in the world that uses very long baseline interferometry. The longest baseline available in this interferometer is about . The total cost of building the VLBA was about $85 million. The array is funded by the National Science Foundation, and costs about $10 million a year to operate.
Each receiver in the VLBA consists of a parabolic dish antenna 25 meters (82 feet) in diameter, along with its adjacent control building. This contains the supporting electronics and machinery for the receiver, including low-noise electronics, digital computers, data storage units, and the antenna-pointing machinery. Each of the antennas is about as tall as a ten-story building when the antenna is pointed straight up, and each antenna weighs about 218 metric tons (240 short tons). The Arecibo radio telescope in Puerto Rico was also used, before it collapsed.
{| class="wikitable"
|+High-Sensitive Array locations
!scope="col"| Toponym
!scope="col"| State
!scope="col"| Geographic coordinate system
|-----
!scope="row"| Green Bank
| West Virginia
|
| GB
|-----
!scope="row"| Very Large Array
| New Mexico
|
| Y27
|-----
!scope="row"| Effelsberg
| Germany
|
| EB
|}
Baseline distance and angular resolution
thumb|Radio telescope at [[Mauna Kea]]
Distance between each VLBA baseline (km):
{| class="wikitable" border="1"
|+Distances between locations
|-
!scope="col" style="text-align:center;"|—
!scope="col" style="text-align:center;"|
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!scope="col" style="text-align:center;"|
!scope="col" style="text-align:center;"|
!scope="col" style="text-align:center;"|
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!scope="col" style="text-align:center;"|
!scope="col" style="text-align:center;"|
!scope="col" style="text-align:center;"|
!scope="col" style="text-align:center;"|
!scope="col" style="text-align:center;"|
!scope="col" style="text-align:center;"|
!scope="col" style="text-align:center;"|
!scope="col" style="text-align:center;"|
|-
!scope="row"|SC
|style="text-align:center;"|—
|2853
|3645
|4143
|4458
|4579
|4839
|5460
|5767
|8611
|6822
|238
|2708
|4532
|-
!scope="row"|HN
|2853
|style="text-align:center;"|—
|1611
|3105
|3006
|3226
|3623
|3885
|3657
|7502
|5602
|2748
|829
|3198
|-
!scope="row"|NL
|3645
|1611
|style="text-align:center;"|—
|1654
|1432
|1663
|2075
|2328
|2300
|6156
|6734
|3461
|1064
|1640
|-
!scope="row"|FD
|4143
|3105
|1654
|style="text-align:center;"|—
|608
|564
|744
|1508
|2345
|5134
|8084
|3922
|2354
|515
|-
!scope="row"|LA
|4458
|3006
|1432
|608
|style="text-align:center;"|—
|236
|652
|1088
|1757
|4970
|7831
|4246
|2344
|226
|-
!scope="row"|PT
|4579
|3226
|1663
|564
|236
|style="text-align:center;"|—
|417
|973
|1806
|4795
|8014
|4365
|2551
|52
|-
!scope="row"|KP
|4839
|3623
|2075
|744
|652
|417
|style="text-align:center;"|—
|845
|1913
|4466
|8321
|4623
|2939
|441
|-
!scope="row"|OV
|5460
|3885
|2328
|1508
|1088
|973
|845
|style="text-align:center;"|—
|1214
|4015
|8203
|5255
|3323
|1025
|-
!scope="row"|BR
|5767
|3657
|2300
|2345
|1757
|1806
|1913
|1214
|style="text-align:center;"|—
|4398
|7441
|5585
|3326
|1849
|-
!scope="row"|MK
|8611
|7502
|6156
|5134
|4970
|4795
|4466
|4015
|4398
|style="text-align:center;"|—
|10328
|8434
|7028
|4835
|-
!scope="row"|EB
|6822
|5602
|6734
|8084
|7831
|8014
|8321
|8203
|7441
|10328
|style="text-align:center;"|—
|6911
|6335
|8008
|-
!scope="row"|AR
|238
|2748
|3461
|3922
|4246
|4365
|4623
|5255
|5585
|8434
|6911
|style="text-align:center;"|—
|2545
|4317
|-
!scope="row"|GB
|2708
|829
|1064
|2354
|2344
|2551
|2939
|3323
|3326
|7028
|6335
|2545
|style="text-align:center;"|—
|2516
|-
!scope="row"|Y27
|4532
|3198
|1640
|515
|226
|52
|441
|1025
|1849
|4835
|8008
|4317
|2516
|style="text-align:center;"|—
|}
The longest baseline in the array is .
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