Документ взят из кэша поисковой машины. Адрес
оригинального документа
: http://www.apo.nmsu.edu/35m_operations/35m_manual/Instruments/Grim/OLD/grim/NICMOS3/NICMOS3.html
Дата изменения: Fri Aug 22 04:22:34 2003 Дата индексирования: Sun Apr 10 10:48:57 2016 Кодировка: Поисковые слова: arp 220 |
GRIM II's detector is a Rockwell 256x256 NICMOS3 HgCdTe array sensitive from 1-2.5 microns. The array's properties are summarized below.
GRIM II Array Characteristics ===================================================== Item Description ----------------------------------------------------- Array size 256 x 256 pixels Pixel size 40 microns x 40 microns Spectral range 1 - 2.5 microns Quantum efficiency(1) approx. 70% Gain(2) 4.73 +- .2 e- A.D.U.^-1 Read noise(2) 110 +- 20 e- Linear well depth (3) 130,000 e- Dark current < 1 e- sec.^-1 ===================================================== Notes: (1) Rockwell measurement (2) Quadrant 4 (3) 28,000 A.D.U. above bias
Click to see the Linearity Plot
The electronic gain and read noise were measured using the photon transfer technique (Janesick, Klaasen, & Elliott 1987). The photon transfer technique uses the data's noise properties to measure the read noise and gain.
Click to see the Photon Transfer Plot
GRIM II uses a correlated double sampling (CDS) readout scheme. Each "exposure" consists of two "reads". The first read occurs at the start of the exposure. The second "read" occurs a the end of the exposure. Moreover, the HgCdTe diodes are accessed twice during each "read". One could therefore define the "read noise" in a number of ways.
The read noise reported here is for a full CDS exposure like an observer would take.
Janesick, J.R., Klaasen, K.P., and Elliott, T. 1987, Optical Engineering, 26(10), 972