The Santa Barbara Channel Experiment (SBCX)

FFP Array Location

The FFP array was deployed in late March, 1998 by SAIC/Maripro. During deployment, they recorded the location of the FFP array and created this plot. On April 15, 1998, one day after the conclusion of the experiment, SAIC/Maripro chartered the Danny C out of Santa Barbara, California, to perform a more precise localization. This involved circling around the FFP array and pinging away every 10 seconds at 10 kHz. The pings were recorded by the FFP array, and using a nonlinear least squares inversion, the locations of the bottom hydrophones of each array were determined (by Peter Daly of MIT and Rob Greene of SAIC).

The Center of the FFP array in UTM coordinates (where the UTM zone = 11) is:

X	285008	meters
Y	3776849	meters

The geographic coordinates for the Center of the FFP array are:

34	degrees	6	minutes	37	seconds	North	Latitude
119	degrees	19	minutes	51	seconds	West	Longitude

The UTM and Latitudinal/Longitudinal coordinates and depth of the bottom phone for each VLA are:

VLA	UTM X(m)	UTM Y(m)	Z(m)	(Lat)				(Long)
1	285059	3776961	197.7 m	34 deg	6 min	41 sec	N	119 deg	19 min	49 sec	W
2	285119	3776827	198.5 m	34 deg	6 min	37 sec	N	119 deg	19 min	47 sec	W
3	284924	3776939	200.2 m	34 deg	6 min	40 sec	N	119 deg	19 min	55 sec	W
4	285029	3776722	204.5 m	34 deg	6 min	33 sec	N	119 deg	19 min	50 sec	W
5	284911	3776798	204.1 m	34 deg	6 min	36 sec	N	119 deg	19 min	55 sec	W

Z is depth below mean low tide.

The FFP array continued to function (although no data was recorded) until the fiber optic cable connecting the array with the shore power and recording station was accidentally severed in the fall of 1998. The array was recovered by SAIC/Maripro in April, 1999. Of the five original VLA's, only three were intact. Two arrays (4 and 5) were damaged and had collapsed on the floor of the channel.

Localization survey information can be found here.

Other estimates of the FFP array position:

• Deployment Survey by SAIC/Maripro: scanned GIF image.



Array Number	UTM X (m)	UTM Y (m)	Latitude	Longitude
1	285040	3776960	34 06 41.03 N	119 19 49.90 W
2	285150	3776810	34 06 36.24 N	119 19 45.48 W
3	284970	3776920	34 06 39.68 N	119 19 52.59 W
4	285050	3776720	34 06 33.25 N	119 19 49.30 W
5	284930	3776780	34 06 35.11 N	119 19 54.03 W
Anode:	3777030	284500	34 06 42.90 N	119 20 11.02 W


From David Iddings of SAIC/Maripro:
The nominal center of the array is 50 meters northwest of the intended center of 34 161 6.600' N and 119 161 19.800' W.


• Recovery Survey by SAIC/Maripro:GIF image.



• Inversion performed by Ross Chapman and Danya Hudson of University of Victoria, Canada: (updated June 28, 2000)

  Array Number	UTM X (m)	UTM Y (m)	Z (m)
  1	285050	3776966	197.5
  2	285110	3776832	199.0
  3	284916	3776945	199.8
  4	285020	3776729	204.2
  5	284902	3776805	204.5

Danya Hudson's preliminary report describing inversion method [PDF] [PostScript]
Danya Hudson's final report describing inversion method [PDF] [PostScript]

Last updated: 000926 change log Comments/Questions: pmd@alum.mit.edu

Ships in the SBCX logo (left to right, from the top) Lockheed P-3 ("Redhook"), USS Acoustic Explorer, USS FLIP, Danny C, USS Dolphin.