ISIS Level 1 FORMAT

Each data file (typical name ISOCTDRA.Y95) has two lines of standard header information on the site.

Line 1:

Item	Contents
1. 	Three letter ID 
2. 	WMO Number  (unassigned = 99999)
3. 	Site Latitude
4.	Site Longitude
5. 	Site elevation
6.	Site time zone (referenced to UTC)
7.	Site data version (labeled so that subsequent calibration factor changes are noted).

Line 2:
 
Column Labels (see Table 2.)

General information:

All data are be reported in Local Standard Time, with statistics generated over a 15 minute period from 1-2 second scans.  Instruments provide the solar broadband irradiances in several wavebands.  The data have been processed through a Quality Control procedure and daily plotting of time series.  Rejected data is replaced with 9999's (primarily normal incident pyrheliometer data because of failure of sun tracking equipment).  The 15 minute mean values are tested against the SERI QC software developed by National Renewable Energy Laboratory (NREL).  This software generates flags for global radiation, normal incident radiation, and diffuse global components.

The remaining measurements are reported as measured along with standard deviations.  Table 1 lists the instrumentation, measurement reported, and estimated data quality as reported from instrument calibrations versus primary standards. 

Table 1.  Integrated Surface Irradiance Study: Level 1 Instrumentation and measurements reported.

Instrument

Measurement

Waveband

Units

Accuracy
Uncertainty

Comments

Precision
spectral 
pyranometer

Global
horizontal
irradiance

0.4 - 2.3 
micrometer

W/m^2

< 5 %

Usually
 < 3 %

NIP
pyrheliometer
(Eppley)

Direct beam
normal 
incident
irradiance

0.4 - 2.3
micrometer

W/m^2

< 2%

Mounted
on sun
tracker

Precision 
spectral
pyranometer

Diffuse
horizontal
irradiance

0.4 - 2.3 
micrometer

W/m^2

< 5%

Mounted and 
shaded on suntracker

Ultra Violet
Biometer
(Solar Light)

UVB global
horizontal
irradiance

290-320
nanommeter

mW/m^2

< 5%

erythema
effective
radiation

Pyranometer
(LiCOR)

Global^4 
horizontal
irradiance

0.4 - 1.1
micrometer

W/m^2

<= 5%

silicon
solid state
detector

Photosynthetic
active 
radiation
(LiCOR)

PAR
global
horizontal
irradiance

0.4 - 0.7
micrometer,
RSR .2 RPM

micro-
Einstein
/s/m^2

<= 5%

under rotating
shadowband
radiometer

Pyranometer
(LiCOR)

Global^4 
horizontal
irradiance

0.4 - 1.1
micrometer

W/m^2

<= 5%

under rotating
shadowband
radiometer

Table 2.  Data Record Contents for ISIS Level 1 Sites

Column	Label		Content

1-5		WBAN	Station number
6-10		Year 		Year
11-14		DOY		Day of year
15-17		MN		Month
18-20		DD		Day of month
21-23		HH		Hour (Local Standard Time)
24-26		MM		Minute (LST)
27-32		Global		Global shortwave in W/m^2
33-35		IfG		Global Flag
36-41		Sgbl		Global standard deviation
42-47		NIP		Direct beam irradiance in W/m^2
48-50		IfN		Direct Flag
51-56		SNIP		Direct beam standard deviation
57-62		Diff		Diffuse shortwave irradiance in W/m^2 (9999 is missing)
63-65		IfD		Diffuse Flag (99 is missing)
66-71		Sdif		Diffuse standard deviation (9999 is missing)
72-77		UVB		UVB Global irradiance in mW/m^2 erythema effective
78-83		Suvb		UVB standard deviation
84-89		PY		Silicon cell pyranometer global irradiance in W/m^2 (9999 is missing)
90-95		SPY		Silicon cell pyranometer standard deviation
96-101		PARrsr  	Global Photosynthetic Active Radiation (PAR) in microEinsteins/s/m^2
mounted under rotating shadowband radiometer (RSR)
102-107	SPAR		PAR standard deviation
108-113	PRSR		Silicon cell pyranometer mounted under RSR in W/m^2
114-119	SPRSR		Standard deviation RSR pyranometer
120-125	PYmx		Maximum of silicon cell pyranometer (global) in W/m^2
126-131	PARmx		Maximum of PAR under RSR
132-137	PRSmx		Maximum of RSR pyranometer
138-143	PYmn		Minimum of Silicon cell pyranometer (global) in W/m^2
144-149	PARmn		Minimum of PAR under RSR
150-155	PRSmn		Minimum of RSR pyranometer
156-161	spare1		Spare1 space holder (Net) 
162-167	sspr1		Spare1 standard deviation (snet)
168-173	solzen		Solar zenith angle
174-179	sspr2		Spare2 standard deviation

All statistics are for the 15 minute period ending in time reported.