Wallops Island Info : Virginia Tech SuperDARN

Wallops Island, VA (37.93 N, -75.47 E)

The SuperDARN radar at Wallops Island was the first to be constructed using the Twin-Terminated-Folded-Dipole (TTFD) antenna design. This design is lighter and cheaper than the original log-periodic design with better backlobe characteristics because of the addition of a reflecting screen. The radar saw first light in June 2005.

The radar is located on the grounds of the NASA Wallops Flight Facility (WFF). It was built and is operated as a joint project of the Johns Hopkins University Applied Physics Laboratory (JHU/APL) supported by NSF and NASA/GSFC.

The original PI was Dr. Ray Greenwald. The PI-ship has since passed through Mike Ruohoniemi, Elsayed Talaat, and Ethan Miller to the current PI, Alex Chartier. Alex assumed the PI-ship on 6 September 2019.

Wallops Island (code: WAL, ID: 32)
Geog. Position: (+37.930°, -75.470°, 50.0m)
Configuration valid from	Configuration valid until	Scanning Boresite [°]	Beam Separation [°]	Velocity Sign	Attenuation Step* [dB]	Time Difference [μs]	Phase Sign	Interferometer Array Position [m]			Receiver Rise Time* [μs]	Stages of Attenuation*	No. of Gates	No. of Beams
	04/Nov/2005 18:00:00.0	35.9	1.62	+1	0	+0.000	+1	+0.0	+100.0	+0.0	0.0	0	110	16
04/Nov/2005 18:00:00.0	01/Jan/2006 12:00:00.0	26.1
01/Jan/2006 12:00:00.0	13/Mar/2006 19:38:00.0		3.24
13/Mar/2006 19:38:00.0	Current	35.9	3.24	+1	0	+0.000	+1	+0.0	+100.0	+0.0	0.0	0	110	24
* Only valid for analog receivers, 0 for digital receivers								Last Updated: Mon Jul 8 07:25:01 2019

Position in Line	Parameter Name	Description
1	Station ID	The unique numeric ID of the radar. Assigned by Rob Barnes.
2	Year	This and the next parameter describe the date up until which the radar configuration described in that line was valid.
3	Seconds in Year	This and the previous parameter describe the date up until which the radar configuration described in that line was valid.
4	Geog. Latitude	The geographic latitude of the radar location, given in decimal degrees to 3 decimal places. Southern hemisphere values are negative.
5	Geog. Longitude	The geographic longitude of the radar location, in degree given in decimal degrees to 3 decimal places. West longitude values are negative.
6	Altitude	The altitude above sealevel of the radar location, in meter.
7	Scanning Boresite	The direction of the center of the field-of-view of the radar, in degree, relative to geographic North, positive clockwise. Traditionally, this direction was the same as the direction of the main antenna array normal.
8	Beam Separation	The angular separation of two adjacent beams, in degree. Normally 3.24 degrees.
9	Velocity Sign	The sign of the velocity direction, either +1 or -1, usually +1.(At the radar level, backscattered signals with frequencies above the transmitted frequency are assigned positive Doppler velocities while backscattered signals with frequencies below the transmitted frequency are assigned negative Doppler velocity. This convention can be reversed by changes in receiver design or in the data samping rate. This parameter is set to +1 or -1 to maintain the convention.)
10	Attenuation Step*	The step size of the receiver attenuation in dB.
11	Time Difference	The relative time delay of signal paths from the interferometer array to the receiver and the main array to the receiver, in microseconds. tdiff = signal_travel_time_from_interferometer_to_receiver - signal_travel_time_from_main_to_receiver If tdiff is positive, the signal travel time from the interferometer array to the receiver is longer than the travel time from the main array to the receiver.
12	Phase Sign	The sign of the phase shift between interferometer and main array, either +1 or -1, usually +1. (Cabling errors can lead to a 180 degree shift of the interferometry phase measurement. +1 indicates that the sign is correct, -1 indicates that it must be flipped.)
13	Interferometer Array Position X	The offset distance between the mid points of the interferometer and main array, in the direction along the main array, positive towards higher antenna numbers, in meter.
14	Interferometer Array Position Y	The offset distance between the mid points of the interferometer and main array, in the direction perpendicular to the main array, positive values indicate that the interferometer array is in front of the main array, in meter.
15	Interferometer Array Position Z	The offset distance between the mid points of the interferometer and main array, in the vertical direction, positive up, in meter.
16	Receiver Rise Time*	The rise time of the analog receiver, in microseconds. (Time delays of less than ~10 microseconds can be ignored. If narrow-band filters are used in analog receivers or front-ends, the time delays should be specified.)
17	Stages of Attenuation*	The maximum number of steps of analog attenuation in the receiver. (This is used for gain control of an analog receiver or front-end.)
18	No. of Gates	The maximum number of range gates from which the radar can receive data. Usually 75. (This is used for allocation of array storage.)
19	No. of Beams	The maximum number of beams the radar can form. Usually 16. Together with the scanning boresite, this parameter defined the direction of each beam relative to geographic North. (It is important to specify the true maximum. This will assure that a given beam number always points in the same direction. A subset of these beams, e.g. 8-23, can be used for standard 16 beam operation.)
* Only valid for analog receivers, 0 for digital receivers		Last Updated: Sun May 28 07:25:01 2023

Wallops Island, VA (37.93 N, -75.47 E)

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