Site Survey Instruments

[ Site Monitoring Instruments ]

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CloudMon

CT2

Instrument Layout at Ali, west Tibet

Control connection among Site monitoring instruments at Ali, Tibet (deployed by Japanese team) (pdf 859 KB)

Schematic Layout of Site Survey Instrument at Ali, Tibet

Software connection and data flow for Site Monitoring

IR Cloud Monitor
Micro-thermal turbulence measurement system (C_T²)
Barometer
Weather Station
Dust Counter
File / internet server ( see Figure )
Remote power controller ( see Figure )
Electric power monitor/logger ( see Figure )
- AC Power Logger : Hioki 3637 (AV range: AC600V) \24,990
- Comminucation Tools for Hioki 3637: Hioki 3912 \31,290
- The logger is available at

[MIR CloudMonitor Sysytem]

CloudMon

Mid_Infrared Cloud Monitor: General description

Schematic of Cloud monitor (Tibet version)	CloudMon layout	Cloud monitor with scale	Cloud monitor at Shipping
Schematic of Cloud monitor (Subaru version)	Cloud Monitor for Subaru	Cloud Monitor for Subaru

Info for IR Cloud Monitor System (CloudMon), which are used at Subaru Telescope, Magnum Telescope at Maui, TAO at Chile, and settled for Site Survey in Tibet/Xinjiang, China. Observation Log Charts is here.

detailed ObsLog obtained at Karasu(2007,2008), Oma(2008,2009) 　　　　

CloudMon Obs Logs 　　　　

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Assemble and test at Advanced Technology Center(ATC), Mitaka during 2006-09-08 - 2006-09-29
- Assemble
  Photos during Assembling of CloudMon at ATC, Mitaka (click right photo)
- Cloud image acquisition test at the roof of ATC, Mitaka on 2006-09-27
  
  CloudMon on roof
  of ATC, Mitaka Cloud image
  (animation 804KB)
  view angle: zenith +-70 deg
- Memo taken in assemble/disassemble in Sep. 2006
  Page 1 / Page 2 / Page 3 / Page 4 / Page 5 / Page 6
- Photos in assembling CloudMon again on 2007-01-17 just before export.
- Takato's paper ( SPIE 2003, pdf:355KB)
  Suganuma's CloudMon paper ( PASP 2007, pdf:698KB)
Disassemble of CloudMon and C_T²(CT2) at Karasu

Camera Head and
My picture

CRT and 2 bottles

Joint Astronomy Center
from Sasaki's Office, Hilo

A40M Camera
Maker	FLIR Systems (Sweden)
Wavelength	7.5 μm - 13 μm
Pixels	320 x 240, unclooled microbolometer
Frame rate	60Hz, 30Hz, ...
Operating Temperaute	-15 - +55 degC
Storage Temperaute	-40 - +70 degC
Humidity(Ope and Store)	20 -95 %
Shock	Vibration 2G Bump 25 G
Size 外形	109mm x 92mm x 207mm
Weight	1.40 kg
Lens レンズ	24deg F/1.0 36mm, Aperture φ45mm focusing: closest(0.3m) - infinity
Interface	Firewire IEEE1394 (400M bps)
Power Unit for A40M camera カメラ電源
Size	117 mm x 54mm x 30mm + cable connector 15mm + 50mm
Power unit	W107m x 50mm x 30mm + cable connector 350mm + 250mm
Model	Nordic Power Model: SA150A-1240U-3
Input	100-240V 50-60 Hz
Output	12Voutput 3.4A 40.8W
FireWire extender
Maker	Gefen, CA, USA
Size	W 100mm + 10mm*2 = 120 mm H 90mm , T 27mm
Model	SITECH Model: SAD03612-UV
Input	100-240V 50/60Hz 1.1A
Output	12.0V 3.0A

Operation manual of CloudMon Control software

Clear Sky ration, measured w/CloudMon at Karasu(2007,2008), Oma(2008,2009), and Gar(2011-2013) are shown below. ( details are shown HERE ).

Comparison of Clear Sky Ratio at Karasu, Oma, Gar/Ali in Tibet, OAO (Japan), Subaru Telescope/Hawaii Haleakala/Maui/Hawaii, and Chajnantor/Chile ( click here to D/L in pdf )	When avilability on usage of telescope is limited under wind speed less than 14m/sec, the ratio of ClearSky is down to nearly the same level at OAO (Okayama, Japan), terribly!
Weather monitoring during Nov 2011 to Dec 2012.	Weather monitoring during Jan 2013 to Jun 2013.

CloudMon

C_T² (CT2) measurement on Microthermal turbulence in Surface Layer

CT2

CT2 Measurement Principle

The refractive index variations arise directly from temperature fluctuations and can be measured by using the temperature fluctuations (Woolf 1982) with

^-5

where C_n² is the refractive index structure coefficient, and C_T² the temperature structure coefficient. Pressure P is in hPa, temund in meter.

Assuming a vertical distribution of C_T² in exponential form with an exponential scale z_h, we obtain seeing at z as

θ(z₀)

^-1/5

^-5

^6/5

₀

^3/5

The temperature structure coefficient, C_T², is defined as

^－2/3

^-2/3

where r is a separation of two temperature sensors in meter.

In our measurement, a separation of a pair of CT2 sensors is 1 meter apart. A total of 10 CT2 sensors on 5 support stays are installed on a 40 m tall tower at Karasu and Oma ( see Photo below).

Principle of CT2 measurement

CT2 Hardware

CT2 sensor	Controller for CT2 sensors, made by Mikami san(NAOJ)	Controller and DIMM Keithley D2701 (Kashi)	CT2 sensors (5 sets) and Barometers (w/ white disk of heat exchanger), Mikami's CT2 Controller and DIMM at Kashi	A total of 10 CT2 sensors on 5 support stays are installed on a 40 m tall tower at Karasu and Oma.	Close-up photo of CT2 sensors on a 40 m tall tower at Karasu.
Electrical block diagram of CT2 Controller, made by Mikami-san.			Bandpass Filter on CT2 Control Circuit, made by Mikami-san.

Control Software Manual for CT2 using DMM Keithley INTEGRA2701

Control Software
for CT2 measurements
Analysis tool of CT2 measurements
to get seeing size from CT2

Comparison of C_T² measurements with OAO-CT2 and China-CT2

Conducted on Feb.04 -Feb.06, 2008 at OAO. Nearly the same results have been obtained except the lower values of CT2 below 10^-6, due to offset treatment of CT2 as no treatment for OAO and treated for China, as shown in Figure of Comparison of CT2 for OAO and China below. For more detailed, see CT2 page

Comparison of CT2
for OAO and China
Level#1 at 27m

CT2 on 2008-02-04UT
with China CT2
Level#1 at 27m

Measurement on C_T² at Karasu and Oma

CT2 measurement has been conducted at karasu and Oma, but no CT2 measurement as strong wind environment at Gar.

Karasu		Oma
CT2 mesurement at Karasu during 2007/10/26 to 2007/11/04	CT2 mesurement at Karasu during 2007/11/01 to 2007/11/15	CT2 mesurement at Oma during 2008/11/19 to 2008/11/25 (ONLY for reference) [ Those raw data showed negative values by about 40%, measurement or hardware setup looks illegal. These data can't be used so far. ... So, the figure show above is created using positive values ONLY for reference. ]	CT2 mesurement at Oma during 2009/10/28 to 2009/10/31
Seeing size derived from CT2 mesurement at Karasu during 2007/10/26 to 2007/11/01	Seeing size derived from CT2 mesurement at Karasu during 2007/11/02 to 2007/11/08	NO Seeing size derived from CT2 mesurement at Oma during 2008/11/19 to 2008/11/25	Seeing derived from CT2 mesurement at Oma with Weather and ClouydMon's Sky condition during 2009/10/26 to 2009/11/01

Related papers:

Miyashita et al. 1989: Site test at Mouna Kea for Subaru Telescope.(pdf: 2.1MB)

Wada et al. 2004: OAO site test for Kyoto 3.5 m telescope. (pdf: 800KB)
Disassemble of CT2 at Karasu
CT2 at Karasu should be disassembled to be packed and tranported to Beijing in 2011. Its CT2 disassemble procedure is shown in pdf file (1.3MB) with disassemble procedure of CloudMon (pdf 1.3 MB).

CT2

Barometer, Vaisala PTB210/SPH20

Barometer with wide range of 500 hPa - 1100 hPa is used with CT2 sensor system to monitor air presuure at the sites. Heatre SPH20 should be attached to PTB210 when a cold envrionment is expected at the sites.

===>

get Japanese Heater SPH20 User Guide ( pdf:266 KB )

===> PTB200 Price (JapaneseYen)
===>

PTB200 Price (quote in Japan)

PTB210/SPH20 Specification
Operation of PTB210
.	Range	500 - 1100 hPa
.	Operation Temperature	-40 at +60 ℃
.	Humidity	no Dew
Precision
.	Linearity	±0.10 hPa
.	Hysteresis	±0..05 hPa
.	Reproduction	±0.05 hPa
.	Precision ( -40 - +60 ℃ )	±0.02 hPa
Spec of heater SPH20
Operation
.	Teperature used	－60～＋80℃
.	Weight	1360 g
Heatrer
.	Power	12 VDC - 24 VDC w/ M12 connector
.	Thermostat ON	＋4℃（ ±3deg)
.	Thermostat OFF	＋13℃（ ±3deg)
.	Power used when thermostat ON	about 70 W

Weather Station, Vaisala WXT510

A weather station, Vaisala WXT510, measures Temperature, Relative humidity, Wind Speed, Wind Direction, RainFall, and HailFall simultaneously.

WXT520 UserGuide (English) avilable.
===> get English WXT520 User Guide ( pdf:2.8MB )
===> get Japanese WXT520 User Guide ( pdf:1.6MB )
===> WXT510 Price (quote in Japan)

WXT510 Specification
Air Temperature
.	Range	-52 - +60 ℃ ( -60 - +140 F ）
.	Accuracy	±0.3 ℃ at +20 ℃
.	Output Resolution	±0.1 ℃
.	Measuring Interval	1 - 3600 sec at one sec steps
Relative Humidity
.	Range	0 - 100 %RH
.	Accuracy	±3 %RH at 0 - 90 %RH
.	.	±5 %RH at 90 - 100 %RH
.	Output Resolution	±0.1 %RH
.	Measuring Interval	1 - 3600 sec at one sec steps
Barometric Pressure
.	Range	600 - 1100 hPa
.	Accuracy	±0.5 hPa at 0 - +30 ℃
.		±1 hPa at -52 - +60 ℃
.	Output Resolution	0.1 hPa, 10Pa, 0.001 bar, 0.1 mmHg, 0.01 inHg
Wind speed
.	Range	0 - 60 m/s
.	Response time	0.25 s
.	Accuracy	±0.3m/s or ±3 % at 0 - 35 m/s s
.		±5 % at 36 - 60 m/s
.	Output Resolution	0.1 m/s
.	Measuring Interval	1 - 3600 sec at one sec steps
Wind direction
.	Azimuth	0 - 360 °
.	Response time	0.25 s
.	Accuracy	±3.0°
.	Output Resolution	1°
.	Measuring Interval	1 - 3600 sec at one sec steps
Precipitation
Rainfall
.	cumulative accumulation after the lastest auto or manual reset
.	collecting area	60 cm2
.	Output Resolution	0.01 mm
.	field accuracy for daily accumulation better than 5 %, weather deopendent
Rain duration
.	counting each 10 second increment whenever droplet detected
.	Output Resolution	10 s
Rain intensity
.	running one minute average in 10-second steps
.	range	0 -200 mm/h
Hail
.	cumulative amount of hits against collecting surface
.	Output Resolution	0.1 hits/cm2, 1hit/in2, 1hit
Hail duration
.	counting each 10 second increment whenever hailstone detected
.	Output Resolution	10 s
Hail intensity
.	one minute running average in 10-second steps
.	Output Resolution	0.1 hits/cm2h, 1hit/in2h, 1hit/h
Operating conditions
Operating voltage	5 - 32 VDC
Temperature	Operation	-52 - +60 ℃
.	Stoage	-60 - +70 ℃
Realative humidity	0 - 100 %RH
Pressure	600 - 1100 hPa
Wind	0 - 60 m/s

Weather monitoring at Gar during Nov 2011 to Dec 2012.

Weather monitoring at Gar during Jan 2013 to Jun 2013.

Dust Counter, DustTrak 8520

DustTrak 8520 measures dust in environment with ranges of 0.001 - 100 mg/m³ .

===>

get English DustTrak8520 Manual ( pdf:1.4 MB )

===>

PTB200 Price (quote in Japan)

DustTrak 8520 Specifications
Sensitivity
.	Sensor type	90° light scattering, laser diode
.	Range	0.001 - 100 mg/m3 (calibrated to respirable fraction of standard ISO 12103-1, A1 test dust)
.	Resolution	±0.1 % of reading or ±0.001 mg/m3, whichever is greater
.	Zero stability	±0.001 mg/m3 over 24 hours using 10-second time-constant
.	Particle size range	0.1.approximate 10 μm (Upper limit is dependent on flow rate)
.	Flow rate range	1.4 - 2.4 L/min
.	Temperature coefficient	+0.001 mg/m3 per °C (for variations from temperature at which DUSTTRAK monitor was zeroed)
Instrument Temperature Range
.	Operating range	0 °C to 50 °C (3 2 °F to 120 °F )
.	Storage range Time	-20 °C to 60 °C (- 4 °F o 140 °F )
.	Time Constant Range	Adjustable from 1 to 60 seconds

SODAR and SNODAR

SODAR
Scitec SFAS	Scitec XFAS
SNODAR dish	SNODAR Enclosure

A sodar antenna emits short acoustic pulses into the atmosphere. The acoustic waves are backscattered at temperature inhomogeneities in the air. The antenna receives the backscattered signals and the subsequent electronics and digital processing evaluates the amplitudes and frequencies. The duration between emission and reception provides the height information about the area to be evaluated.
Since the temperature inhomogeneities move with the wind, a Doppler frequency shift is observed revealing the wind speed relative to the beams axes. If this Doppler shift is measured at different beam directions, the three-dimensional wind profile is obtained. The amplitude of the backscattered signals supplies information about the strength of the thermal turbulence.

Spec for Scitec SODARs( samll SFAS and large XFAS) avilable.
===>

get the SODAR info ( pdf:1.2MB )

===> get the SODAR Price list

Snodar is a high resolution acoustic radar designed specifically for profiling the atmospheric boundary layer.
Snodar profiles the atmospheric temperature structure function constant to a vertical resolution of 1 m or better with a minimum sample height of 8 m. The maximum sampling height is dependent on atmospheric conditions but is typically at least 100 m. Snodar uses a unique in-situ intensity calibration method that allows the instrument to be autonomously recalibrated throughout the year.

Spec for SNODAR avilable.
===>

get the SNODAR info ( pdf:271KB )

DIMM, MASS