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COMPONENT |
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Throughput allocation varies over spectral range of the camera ; see Section 4.1.2. |
Exceeded allocated throughput, with the exception of the 200-400 nm region (falls as much as 1.64 % below allocated throughput in this region). |
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COMPONENT |
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Throughput allocation varies over spectral range of the camera ; see Section 4.1.2. |
Falls below allocated throughput except for the region between 442.5 nm and 490 nm. |
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The WAC optics was inherited from Voyager with the policy being "use as is". |
COMPONENT |
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+/- 4 mm |
Estimated measurement uncertainty of 4mm is outside the +/- 0.5 mm accuracy requirement. |
From E. Motts. |
COMPONENT |
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+/- 0.251 mm |
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From E. Motts memo. |
COMPONENT |
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From B. Wallis/K. Manatt Optics Report. |
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COMPONENT |
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From B. Wallis/K. Manatt Optics Report. |
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COMPONENT |
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Average exposure +/- 1 msec |
Greatest offset = 1.65 msec at -10C for 25 msec measurement. Five measurements in all exceeded the +/- 1 msec rqmt : all 3 temp measurements for 25 msec and -10C measurements for 5 msec and 100 msec. No shutter bounce observed. |
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Although component level offsets do not meet the requirement, subsystem level tests showed the offset requirement was met. |
COMPONENT |
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Average exposure +/- 1 msec |
Greatest offset < 0.5 msec at -10C for 25 msec measurement. No shutter bounce detected. |
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COMPONENT |
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RQMT : Off- axis point-source attenuation factor <= 10-4 at 6 ° off-axis , and <= 10-10 at 40 ° off-axis GOAL : Off- axis point-source attenuation factor <= 1.03x10-12 @ 6 ° off-axis , and <= 3.68x10-15 @ 40 ° off-axis |
VISIBLE : Off- axis point-source attenuation factor = 1.7x10-8 at 6 ° off-axis , and = 2.8x10-12 at 40 ° off-axis
UV : Off- axis point-source attenuation factor = 5.8x10-9 at 6 ° off-axis , and = 5.2x10-10 at 40 ° off-axis |
RQMT : YES
GOAL : IN PART |
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SUBSYSTEM |
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Identify pixels whose response as a function of exposure cannot be reliably calibrated. |
Blemishes mostly confined to image borders.
Image interior pixels flagged as blemishes limited to 3 in Gain 2 and 1 in Gain 1 (all within 3 pixels of any border). High exposure behavior generally caused pixels to be flagged as blemishes. Gain 0 exhibited spatial relationship w/ respect to the degree of response shortfall at high exposures. Anti-blooming pixel pairs for long exposures observed. |
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SUBSYSTEM |
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Identify pixels whose response as a function of exposure cannot be reliably calibrated. |
Blemishes mostly confined to image borders.
Blemishes found in 1st 100 pixels of line 2 (200 pixels in 4x4 mode). Only one image interior pixel flagged as blemishes for 2x2 summation mode. Low exposure behavior generally caused pixels to be flagged as blemishes. Gain 2 exhibited spatial relationship w/ respect to the degree of response shortfall. Anti-blooming pixel pairs for long exposures observed. |
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SUBSYSTEM |
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<= 0.3 e-/pixel/sec @ operating temperature
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Dark Current mean DN ranges from -0.001 DN @ 5 msec (overcompensated from bias) to 28.744 DN @ 1200 sec.
Gain 3 sensitive to Sensor Head temp. Antiblooming has no significant effect. With Lightflood "Off", the mean DN does not rise above noise except for 1000 and1200 sec exposures. With Lightflood "On", rhe mean DN does not rise above 0.5 DN until after an exposure of 1.5 sec. Line number profile observed with Lightflodd "On". Simultaneous imaging will change profile if NAC readout second.
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Dark current has many dependent variables; in-flight calibration recommended.
NAC dark frame data has coherent noise patterns from unknown source (presumably environmental). |
SUBSYSTEM |
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<= 0.3 e-/pixel/sec @ operating temperature
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Dark Current mean DN ranges from -0.15 DN @ 5 msec (overcompensated from bias) to 30.73 DN @ 1200 sec.
Gain 3 sensitive to Sensor Head temp. Antiblooming has no significant effect. With Lightflood "Off", the mean DN does not rise above noise except for 1000 and1200 sec exposures. With Lightflood "On", rhe mean DN does not rise above 0.5 DN until after an exposure of 1.2 sec. Line number profile observed with Lightflood "On". Simultaneous imaging changes the line profile (WAC imaged readout 2nd by default).
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Dark current has many dependent variables; in-flight calibration recommended. |
SUBSYSTEM |
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SUBSYSTEM |
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Mean coefficient value for all images at nominal target position is 9.51x10-9 +/-
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SUBSYSTEM |
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and WAC |
< 60 e- rms
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Bias frames (0 sec exposure) have low amplitude noise spectrum.
Significant vertical fixed pattern noise consistent w/ CCD "step-and repeat" pattern of mfg process (@ frequency of 0.0233 and its harmonics). Horizontal fixed pattern noise from 0 to 0.1 cycles per second (1x1 mode) for exposed frames. Shows up at lower resolution @ other summation modes. Most likely due to "step-and-repeat" pattern of CCD. No vertical electrical noise apparent. Anti-blooming "on" increases the amplitude for well-exposed frames. No difference observed due to change in temperature or lossless compression. |
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SUBSYSTEM |
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Gain 0,1 and 2 : provide encoding with the maximum DN value occurring between 90 and 100% average CCD fullwell capacity for specified summation mode Gain 3 : 12 e-/DN |
@ +25C
Gain 0 : 219.8 e-/DN Gain 1 : 99.32 e-/DN Gain 2 : 29.15 e-/DN Gain 3 : 13.93 e-/DN @ +5C
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Gain 0 : 4x4 summation
Gain 1 : 2x2 summation Gain 2 : 1x1 summation Gain 3 : 1x1 summation |
SUBSYSTEM |
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Gain 0,1 and 2 : provide encoding with the maximum DN value occurring between 90 and 100% average CCD fullwell capacity for specified summation mode
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@ +25C
Gain 0 : 194.30 e-/DN Gain 1 : 90.13 e-/DN Gain 2 : 27.66 e-/DN Gain 3 : 11.74 e-/DN @ +5C
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Gain 0 : 4x4 summation
Gain 1 : 2x2 summation Gain 2 : 1x1 summation Gain 3 : 1x1 summation |
SUBSYSTEM |
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Detect light leaks (shutters closed) w/ ave response >= 0.1 DN, or pixel response > 2 DN for on axis irradiance as great as 100x that expected at Saturn. |
<= 0.6 DN @ equivalent of 1000 seconds of exposure to Saturn or 12000 X what would have given fullwell response.
No signal trend noted with exposure time. |
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SUBSYSTEM |
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Detect light leaks (shutters closed) w/ ave response >= 0.1 DN, or pixel response > 2 DN for on axis irradiance as great as 100x that expected at Saturn. |
<= 1 DN @ equivalent of 100 seconds of exposure to Saturn or 10,000 X what would have given fullwell response.
Linear signal increase with exposure time. |
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SUBSYSTEM |
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Linear response with standard deviation from that response <=1%. |
Linear to within 1%, except for 4x4 mode. 4x4 linear to 1000 DN. |
with the exception of 4x4 mode |
+25C data more well-behaved than +5C data. 4x4 linearity breakdown at 1000 DN. |
SUBSYSTEM |
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Linear response with standard deviation from that response <=1%. |
Linear to within 1%, except for 4x4 mode. 4x4 linear to 1000 DN. |
with the exception of 4x4 mode |
4x4 linearity breakdown at 1000 DN. |
SUBSYSTEM |
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>= 0.15 @ 32 line pairs / mm |
Tabulated values show MTF with contributions from window and collimator ranging from 0.10 to 0.24. 80% of the tested filter combinations have an MTF >= to 0.15 (with window and collimator contributions). If the contributions from the window and collimator were removed, all MTF values would be above 0.15. |
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SUBSYSTEM |
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>= 0.15 @ 32 line pairs / mm |
Tabulated values show MTF with contributions from window and collimator ranging from 0.030 to 0.393. 59% of the tested filter combinations have an MTF >= to 0.15 (with window and collimator contributions). If the contributions from the window and collimator were removed, all but perhaps 3 of the MTF values would be above 0.15. |
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Wide variation in filter MTF quality was expected because of focus tradeoffs in the design.
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SUBSYSTEM |
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Best Effort |
PO / CL2 : -0.5 ° P60 / CL2 : 61.8 ° P120 / CL2 : 120.8 ° IRP0 / CL2 : 2.25 ° |
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SUBSYSTEM |
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Best Effort |
CL1 / IRP0 : 0.00 ° CL1 / IRP90 : 90.85 ° |
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SUBSYSTEM |
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average exposure +/- 1 msec |
Absolute greatest shutter offset value < 0.2 msec. Shutter offset value passes through 0 within the frame indicating right side of frame has a longer exposure time than commanded and vice versa. |
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A horizontal band of increased shutter offset value observed in the mid-portion of the frame. Suspect dark current bias vs frame line profiles not properly accounted for. |
SUBSYSTEM |
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average exposure +/- 1 msec |
Absolute greatest shutter offset value < 0.7 msec. All shutter offset values negative indicating that the actual exposure time is longer than the commanded time. |
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A horizontal band of increased shutter offset value observed in the mid-portion of the frame. Suspect dark current bias frame vs line profiles not properly accounted for. |