Filter: 500 nm
Bandwidth: 5 nm
Effective Bandpass: The spectral profile can be found on the ftp server: ftp.estec.esa.nl/pub/loitenerife/PurpleBook. It is an ascii file called LOIAndover.dat with 2 columns (wavelength, transmission).
/optical depth: To be derived from the bandpass
Detector: Deep diffused silicon photodiode with 12 scientific and 4 guiding pixels as given in Figure LOI-1. The crosstalk between pixel is smaller than 10-4.
Power on detector: 0.8 mW/cm2
Temperature sensitivity: about 50-100 ppm/K
Aging of temperature sensitivity: drift of -400 ppm/K to be controlled with a ground copy of the flight detector
Temperature sensitivity: to be measured
UV sensitivity: No degradation after 1 year of solar UV (below 400 nm)
Particle sensitivity: 5% relative transmittance drop after a 7-year SOHO dose.
Surface contamination: temperature of the filter should be about 10 0C higher than the structure, and should prevent condensation of contaminants.
Angular sensitivity: Unknown
Thermal stability : 0.2'/K
Voltage sensitivity: 16' for 650 Volts
High voltage supply: -150 to 450 Volts
Servo loop aging: unknown
Guiding power Spectrum:
EW axis: 5 "/[[radical]]Hz @ 0 Hz, 3.2 "/[[radical]]Hz @ 9000 uHz, linear dependence in the power spectrum, [[sigma]]=0.4".
NS axis: 3.16 "/[[radical]]Hz @ 0 Hz, 2.23 "/[[radical]]Hz @ 9000 uHz, linear dependence in the power spectrum, [[sigma]]=0.26"
Diameter Measurements: Spectrum rather flat 3.2 "/[[radical]]Hz, [[sigma]]=0.17".
The above power spectra are based on ground-based measurements. They are essentially limited by the atmospheric seeing and its associated transparency changes. These spectra should, hopefully, be better in space.
VF converters: 1 ppm/K
Short Term (5-min range): <0.5 ppm2/uHz (ground-based measurements, limited by the atmosphere)
Dark current noise: See Fig SPM-I
Long Term: unknown. Most of the noise contribution will be due to the temperature fluctuations on the filter and detector.
Last updated by Thierry Appourchaux on Thursday December 11, 1997 at 13:14