699-416
SUB-APPENDIX F6 - SPHERE RADIOMETRIC CONVERSION FACTORS
The red radiometer system, used for measuring the sphere's radiant output for thermal vac calibration testing, measured the sphere's radiant output via a calibrated silicon photodiode detector head containing a Hammamatsu 1337-1010BQ diode. Current levels from the photodiode were read with a Keithly 617 electrometer. This red radiometer system was calibrated 3 separate times by David Brown using a calibrated lamp. This data was compared to data taken previously with the calibrated lamp, as well as with data taken from a typical lamp used for flight calibration testing.
The conversion factors shown in the table below were based on the latest red radiometer system calibration taken with the calibrated lamp on 7/15/96 (towards the end of flight calibration testing). The listed conversion factors (in units of W/m2 /sr/nm/A) are given to convert from units of amperes (A) to units of radiance (in units of W/m2 /sr/nm). These conversion factors are required due to the fact that, during calibration testing, the radiant output of the sphere was measured as current from the photodiode (recorded in the VICAR label in units of picoamps). Note that the current readings recorded in the image VICAR label were made with the 700 nm Melles Griot filter installed in the red radiometer system.
|
Wavelength
|
Current to Radiance Conversion Factors
Data from 7/15/96
(W/m2/sr/nm/A)
|
|
350
|
2.5735E+06
|
|
400
|
2.6788E+06
|
|
450
|
2.0063E+06
|
|
500
|
1.1694E+06
|
|
550
|
1.2717E+06
|
|
600
|
1.0943E+06
|
|
650
|
9.4540E+05
|
|
700
|
1.0879E+06
|
|
750
|
9.6294E+05
|
|
800
|
8.7264E+05
|
|
850
|
1.1544E+06
|
|
900
|
1.3885E+06
|
|
950
|
2.5225E+06
|
|
1000
|
6.1780E+06
|
|
1050
|
1.4085E+07
|
|
1100
|
5.1665E+07
|
Sphere Current to Radiance Conversion Factors Table
