This page contains various bits of information I have gathered related
to the possibility of connecting the VLBA antennas to a correlator with
fiber optics in real time. The major concern is cost. There are two
components to that cost. The first is the cost of the "last mile"
connection to each site, which depends on a combination of distance
and technology used. The second is the cost of access to sufficient
bandwidth on the long distance lines. Most of the information below
relates to the last mile. We still have very little concept of the
long haul costs other than that, if we have to pay typical rates for
Internet bandwidth, it is prohibitive.
|
Site |
Longitude |
known fiber (km) |
|
| St. Croix | 17:45:24 64:35:01 |
3 - 5 | AT&T has a fiber backbone running the length of the island. We speculate that we might be able to attach at a casino 2-3 miles away. The local telephone company is not using this fiber. One of the site techs (Pete) used to work for AT&T. |
| Hancock | 42:56:01 71:59:12 |
7 | Mark Alfero talked to a phone company person in the field and was informed that the VLBA stations is 23,000 ft from the central office in Hancock and that there is fiber there. He is waiting for more info from the phone company engineers. |
| North Liberty | 41:46:17 91:34:27 |
<0.5 | There is OC48 fiber under the driveway - within 1/4 mile. The local telephone cooperative would splice into there line there. They have all the equipment in place for an "ATM cloud". |
| Fort Davis | 30:38:06 103:56:41 |
13 (or 3) | There is a Southwest Bell fiber to McDonald Observatory. The best place to connect might be Fort Davis. That is where the Southwest Bell office is that deals with McDonald. Distance to Fort Davis, according to INFOSYS is 8 miles. The McDonald fiber passes about 2 miles from our site so the connection could be closer if the fiber could be tapped. |
| Los Alamos | 35:46:30 106:14:44 |
Unknown. | There could be problems getting to the tech area front gate because there are concerns about possible hazardous materials in the area. Once outside, there should be fiber nearby, but we don't know yet. We are asking for a quote for service from Qwest as part of the EVLA project. |
| Pie Town | 34:18:04 108:07:09 |
Connected | Western New Mexico fiber to VLA is currently in use. Old AT&T fiber crosses driveway and has stub, we think. |
| Kitt Peak | 31:57:23 111:36:45 |
0.1 | I talked to Steve Grandi of KPNO on
9sep2001. The Tohono O'odham Utility Authority has just pulled fiber
to the top of Kitt Peak. It was strung on power poles up the
mountain, then in conduit around the top. KPNO is leasing a DS3 line
which will be on an OC192 connection being used by the utility. One
small problem is that the West Ridge, where the VLBA antenna is
located, is not connected to the peak by fiber. Last time a
connection was investigated, the cost was $20-30k. The power poles
that would be used may not be owned by the tribe. The copper cables
are owned by KPNO.
UPDATE: VERTAS, down by the lake, is having a fiber installed in early 2005 along the power and telephone lines that go through the picnic area. The contractor is leaving a drop for us in case we need it in the future. So fiber will be very close. |
| Owens Valley | 37:13:54 118:16:37 |
10 | I contacted Dave Woody at OVRO on 7sep2001. He says that there is fiber down the valley and that the nearest connection is in Big Pine, about 10 km away. There are power poles to close to OVRO, but all on-site lines are burried. The telephone line is burried to Big Pine on a shorter route than that taken by the poles. If we do decide to connect, we should contact Dave or Steve Scott because they would be interested in upgrading the connections to OVRO. |
| Brewster | 48:07:52 119:41:00 |
0 | When fiber was laid to the Veristar antennas on the hill above our site, they left a point to connect at our site. The line is controlled by Veristar and we have been given a name to contact for information. |
| Mauna Kea | 19:48:05 155:27:20 |
1 | There is fiber to the top of the mountain. We might need to attach at the top. We don't know the capacity. |
| GBT | 38:25:59 79:50:23 |
Unknown | This is not a VLBA station, but should be connected in any real time scheme. |