1. Authors: U.S. Army Research Laboratory, Adelphi, MD 20783 P.I. John Noble, (301) 394-5663, jnoble@arl.army.mil Mark Coleman, (301) 394-5602, mcoleman@arl.army.mil Giap Huynh, (301) 394-1156, ghuynh@arl.army.mil 2. Sensors a. Sonic anemometers - ATI type 'K' SAT-211/3K three-axis sonic anemometer/thermometer mounted at 2m on each of the 5 towers and 5m on towers 3 and 5. The sonic gives temperature and 3-axis winds at a rate of 10 Hz. The data are labeled u, v, w where u is the East-West component with a positive value indicating West for u, South for v, and up for w. b. Tower microphones - B& K and Larson-Davis microphones were placed at 4 levels (0.5, 1.0, 2.0, 3.0 m). The data were collected on DAT using Sony 8 channel PC208Ax recorders with a bandwidth from DC to 5 kHz and a 12 kHz digitization rate. c. Transverse microphone array - There were 3 transverse microphone arrays containing 8 microphones equally spaced. The data were collected using a sensor node that digitized the data at 4096 Hz and saved the data to disk. d. Location of sensors: There are 2 graphics included that shows the layout of the towers. Tower 1: 37o 38' 27.6" N 96o 45' 4.2" W El: 1410 ft Tower 2: 37o 38' 34.3" N 96o 45' 4.0" W El: 1410 ft Tower 3: 37o 38' 40.6" N 96o 45' 3.7" W El: 1410 ft Tower 4: 37o 38' 47.0" N 96o 45' 3.6" W El: 1415 ft Tower 5: 37o 38' 54.2" N 96o 45' 1.9" W El: 1435 ft 3. Sources: a. Speaker - A speaker was placed 1 m above the ground. The speaker produced a 50 Hz square wave that provided multiple frequencies of 50, 150, 250, 350, ... to the roll off of the speaker (2 kHz). The square wave was broadcast for 2hrs blocks of time with a break every 4hrs to refuel the small portable generator running the electronics. The source location was 37o 38' 15.9" N, 96o 45' 4.6" W El: 1405. b. Propane cannon - One 20-minute run was made using a propane cannon. The cannon was set to produce an impulse every 30 sec. The cannon was co-located with the speaker. 4. Units: a. Wind speed was measured in m/s. b. Temperature was measured in C. c. Acoustic data were calibrated in pascals. 5. Quality control: a. The 2m and 5m sonics on tower 5 contained too many spikes for the data to be used for calculating the turbulence statistics. We are working on being able to retrieve mean values from the data. The tower 5 data will not be included in the ARL dataset. If you are interested in the mean levels, please contact the P.I. to see if the mean levels were retrieved. b. Cow damage - The following 2m sonics were down due to damage to the data cables by cows: IOP Tower Down time 00 3 Entire IOP 03 1,4 Entire IOP 06 1 10:23:03.3-10:37:06.0 07 1 Entire IOP 08 4 00:07:12.9 - rest of IOP 09 4 08:03:58.9 - rest of IOP c. Tower microphones - The microphones are checked for a valid signal after being extracted from the DAT. A more detailed description will be provided when the acoustic data is available. 6. Sonic data files: a. File name format IXXTYLZMMDD.dat Where XX is the IOP number, Y is the tower number, Z is the tower level number (2 or 5), MM is the month, and DD is the day of the month. The files are divided into directories according to the IOP. To save space, the files have been compressed using PKZIP. b. File format: YYYY JJJ HH MM SS XXX UU.UU VV.VV WW.WW TT.TT Where YYYY is the year, JJJ is the Julian day, HH is the hour (GMT), MM is the minute, SS is the second, XXX is the milliseconds, UU.UU is the u-component, VV.VV is the v-component, WW.WW is the w-component, and TT.TT is the temperature. 7. Acoustic data files - The acoustic data files will be available by request from the above P.I. starting in January. Due to the large data size of the acoustic runs, please limit requests to time periods from IOP instead of the entire acoustic data set. I am looking into ways to automate the replication of the acoustic data in mass quantities.