ISIS Level 1 FORMAT

Each data file (typical name ISOCTTLH.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 (labelled 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. Measurements reported are 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 are 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/m2 < 5 % Usually

< 3 % NIP

pyrheliometer

(Eppley) Direct beam

normal

incident

irradiance 0.4 - 2.3

micrometer W/m2 < 2% Mounted

on sun

tracker Precision

spectral

pyranometer Diffuse

horizontal

irradiance 0.4 - 2.3

micrometer W/m2 < 5% Mounted

under

shadowband Ultra Violet

Biometer

(Solar Light) UVB global

horizontal

irradiance 290-320

nanommeter

mW/m2 < 5% erythema

effective

radiation Pyranometer

(LiCOR) Global4

horizontal

irradiance 0.4 - 1.1

micrometer W/m2 <= 5% silicon

solid state

detector Photosynthetic

active

radiation

(LiCOR) PAR

global

horizontal

irradiance 0.4 - 0.7

micrometer,

RSR .2 RPM micro-

Einstein

/s/m2 <= 5% under rotating

shadowband

radiometer Pyranometer

(LiCOR) Global4

horizontal

irradiance 0.4 - 1.1

micrometer W/m2 <= 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/m2

33-35	IfG	Global Flag

36-41	Sgbl	Global standard deviation

42-47	NIP	Direct beam irradiance in W/m2

48-50	IfN	Direct Flag

51-56	SNIP	Direct beam standard deviation

57-62	Diff	Diffuse shortwave irradiance in W/m2 (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/m2 erythema effective

78-83	Suvb	UVB standard deviation

84-89	PY	Silicon cell pyranometer global irradiance in W/m2 (9999 is missing)

90-95	SPY	Silicon cell pyranometer standard deviation

96-101	PARrsr	Global Photosynthetic Active Radiation (PAR) in microEinsteins/s/m2

mounted under rotating shadowband radiometer (RSR)

102-107	SPAR	PAR standard deviation

108-113	PRSR	Silicon cell pyranometer mounted under RSR in W/m2

114-119	SPRSR	Standard deviation RSR pyranometer

120-125	PYmx	Maximum of silicon cell pyranometer (global) in W/m2

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/m2

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.