LROC Calibrated Data Record Narrow Angle Camera (CDRNAC)
CDRNAC – Calibrated Data Record Narrow Angle Camera
Instrument: Lunar Reconnaissance Orbiter Camera
PDS3 Data Set ID: LRO-L-LROC-3-CDR-V1.0 DOI: 10.17189/1520241 Citations of DOI: 10.17189/1520241
PDS4 Bundle: urn:nasa:pds:lro-l-lroc-3-cdr-v1.0 DOI: 10.1007/s11214-010-9634-2 Citations of DOI: 10.1007/s11214-010-9634-2
For more information about LROC calibrated products, see the CDR Product SIS.
For more information about the PDS3 volume, see the LROC Archive Volume SIS.
The Lunar Reconnaissance Orbiter Camera (LROC) Calibrated Data Record Narrow Angle Camera (CDRNAC) data products contain calibrated panchromatic NAC image data. NAC Digital Numbers (DNs) are decompanded and images are radiometrically calibrated to radiance (i.e. star observations) or I/F (i.e. lunar observations). Radiance images are archived as floating point values (4 bytes per pixel) and I/F images as scaled signed-integer values (2 bytes per pixel). The I/F values are multiplied by 32767 before being converted to signed-integer.
The image data consists of one series of contiguous lines up to 52,224 lines with 5,000 samples in full resolution mode, or 104,448 lines with 5,000 samples in 2x crosstrack summation mode. The CDRNAC data are delivered in 16-bit format.
Specifications for the right and left NACs are in the table below. The NAC-L is off-pointed ~2.85° from the NAC-R so that the footprints of the two images overlap ~130 pixels.
|
|
NAC-L |
NAC-R |
|
FOV |
2.8502° |
2.8412° |
|
IFOV |
10.0042 μrad |
9.9764 μrad |
|
Image scale at 50 km altitude |
0.5 m/pixel |
|
|
Maximum image size at 50 km altitude |
2.49 x 26 km |
2.48 x 26.1 km |
|
f/# (Ritchey-Chretien) |
3.577 |
3.590 |
|
Effective focal length |
699.62 ± 0.08 mm |
701.57 ± 0.09 mm |
|
Distortion coefficient |
0.0000181 ± 0.0000005 |
0.0000183 ± 0.0000005 |
|
Optical center location |
sample 2548 ± 8 |
sample 2568 ± 8 |
|
Primary mirror diameter |
198 mm |
|
|
MTF (Nyquist) |
0.23 |
|
|
Gain |
90.5 ± 2.6 e-/DN |
92.5 ± 1.5 e-/DN |
|
Noise |
101 ± 7 e- |
97 ± 2 e- |
|
Detector fullwell |
334,000 ± 31,000 e- |
352,000 ± 4100 e- |
|
SNR (400-750 nm) |
> 52 |
> 49 |
|
Detector digitization |
12-bit, encoded to 8-bits |
|
|
Lossless compression ratio |
1.7:1 |
|
|
Structure + baffle |
Graphite-cyanate composite |
|
|
Detector |
Kodak KLI-5001G |
|
|
Pixel format |
1 x 5,064* |
|
|
Analog/digital converter |
Honeywell ADC9225 |
|
|
FPGA |
Actel RT54SX32-S |
|
|
Voltage |
28 ± 7V DC |
|
|
Peak power |
9.3 W |
|
|
Orbit average power |
6.4 W |
|
|
Mass (both NACs) |
16.4 kg |
|
|
Volume (length x diameter) |
118 cm x 27 cm (incl. radiator) |
|
*Of the 5064 pixels, 39 masked pixels on the right and 21 masked pixels on the left are used for dark reference.
LROC CDRNAC products have the following file names:
TNNNNNNNNNNAC.IMG
where:
t = target
M = Moon
E = Earth
C = calibration
S = star
nnnnnnnnnn = 10-digit Mission Elapsed Time of acquisition (with a single digit for partition which denotes a reset of the MET)
a = single character denoting the instrument
R = right NAC
L = left NAC
In ODE, CDRNAC products have the following product IDs:
nac.tnnnnnnnnnnac