SOAS

ISFS Planning and Logistics

Tower Power

Estimates of power usage on the tower.

Height Usage Power in Watts (max)
45m CSAT, Li7500, TRH, Etherant  2+10(30)+1+10=23(43)
39m CSAT+EC150, TRH, DSM, 3G, 4G, WWWcam 4+1+5+6?+6?+12 = 34
33m CSAT, Li7500, TRH 2+10(30)+1 = 13(33)
27m  CSAT, Li7500, TRH, DSM 2+10(30)+1+5 = 18(38) 
21m  CSAT, Li7500, TRH 2+10(30)+1 = 13(33) 
15m  CSAT, TRH 2+1 = 3
 9m CSAT, Li7500, TRH  2+10(30)+1 = 13(33)
 2m CSAT, TRH 2+1 = 3 

Data Estimates


Sensor # rate
Hz		 rec length
(bytes)		 size/day
CSAT3 sonic 5 20 12+16=28 242 MByte
CSAT & krypton 2 20 14+16=30 104 Mbyte
EC150 1 25 122+16=138 298 Mbyte
Licor 7500 5 20 49+16=65 562 Mbyte
Paro6000 Barometer 4 14.85 17+16=33 169 Mbyte
total       1475 Mbyte

Testing in the EOL staging area, over a WIFI (AP24/Etherant)and 10-Base Fiber connection showed a consistent 165 Kbyte/sec transfer of a NIDAS binary data file from the "high" dsm, which had a flash-type USB disk. This was using rsync, with on-the-fly compression. Downloading 1475 Mbyte over this connection will take about 9000 seconds= 2.5 hours every night.  The file copy was done while the normal real-time data was also being sent to the dsm_server via TCP.

May 9: upgraded to 100-Base-FX fiber converters.  Compressed transfer of a 111.9 MByte file took 8:44, at a reported rate of 208 kByte/sec, and a total of 30.0 MByte was transferred (compressed 119.9 Mbyte to 30.).  Uncompressed transfer took 6:14 at an reported rate of 291 kByte/sec. Seems that uncompressed is faster - probably because the Viper is a slow CPU.

So not using compression, and assuming 291 kByte/sec, the nightly transfer of 1475 MByte will take about 5068 secs = 1.4 hours.

Networking

Networking during SOAS used every type of media we had, but all worked well:
  • 2x 3G modems in Cradlepoint router at the top of the tower
  • Copper RJ45 running down the tower to a switch in bottom DSM
  • Copper RJ45 running back up the tower to mid DSM?
  • Copper RJ45 strung along the trees to chemistry trailers along the tower access road.
  • A WiFi access point in one chemistry trailer.
  • Fiber optic cable running ~600m between bottom DSM at the tower and the Base trailer.
  • A WiFi access point and switches in the Base trailer.
  • Long-distance WiFi access point also at Base trailer.
  • Long-distance WiFi station adaptors at each of Pond DSM, SODAR, and LIDAR.

Logistics at AABC Site

  • Base trailer was parked near a carport with an existing live power drop.
  • Porta-Potty was placed near trailer.
  • Power cable was run by hand 1800' from this power drop (two seperate 220V circuits) to transformers on the road by the tower.
  • Tower was powered by cable from these transfomers.
  • Two small trailers (TRAM + CU) were parked on the road for chemistry instrumentation and also powered from the transformers.
  • The tower was erected just before leaf-out to facilitate running guy wires.
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