MRO CRISM Targeted Reduced Data Record (TRDR)
Instrument: Compact Reconnaissance Imaging Spectrometer for Mars
PDS Data Set ID: MRO-M-CRISM-3-RDR-TARGETED-V1.0
For more information about CRISM products, go to the CRISM Product Primer.
For more information about TRDRs, see the CRISM Data Product SIS.
A Targeted Reduced Data Record (TRDR) is a radiometrically calibrated CRISM spectral image cube derived from raw Experiment Data Record (EDR) products, i.e. from a single observation. TRDRs have been resampled in the spectral or spatial direction. If resampling has been performed, that is indicated in the label and file name.
TRDRs contain one or more multiple-band images that have been converted from EDRs to units of spectral radiance or I/F.
Spectral radiance is defined as: W / (m2 micrometer steradians)
I/F is defined as the spectral radiance divided by the spectral radiance of the Sun at Mars distance at the time of observation. Another way to put it is that it is the ratio of the radiance observed from a surface to that of a perfect white Lambertian surface illuminated by the same light source but at normal incidence.
I is defined as: power / area / I / steradians
F is defined as: (solar irradiance at Mars) / pi
where the (solar irradiance at Mars) is the solar spectral irradiance as seen by a normally illuminated surface 1 AU from the sun adjusted for the distance of Mars from the sun for that particular observation.
CRISM Observing Modes Used
Mode |
Pointing |
Description |
Coverage |
---|---|---|---|
Targeted (hyperspectral) |
Tracking as shown, once per target |
Full resolution (FRT) Spatial pixels unbinned for target – 18 m/pixel @ 300 km, 10x binned for EPF |
~6500 per Mars year |
Half resolution short (HRS) Spatial pixels 2x binned for target – 36 m/pixel @ 300 km, 10x binned for EPF; same swath length as above |
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Half resolution long (HRL) Spatial pixels 2x binned for target – 36 m/pixel @ 300 km, 10x binned for EPF; twice swath length as above |
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Full resolution short (FRS) Spatial pixels unbinned for target – 18 m/pixel @ 300 km; half swath length as above |
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Along-track oversampled (ATO) Spatial pixels unbinned for target – 18 m/pixel cross-track, up to ~3 m/pixel downtrack, requires special processing for increased resolution; half swath length as above |
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Along-track undersampled (ATU) Spatial pixels unbinned for target – 18 m/pixel cross-track, 36 m/pixel downtrack; half swath length as above |
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Atmospheric (hyperspectral) |
Tracking as shown but only center of target measured |
EPFs Spatial pixels 10x binned (~200 m/pixel @ 300 km) |
Lat./lon. grids every ~9° of Ls |
Nadir-pointed |
Tracking Optical Depth (TODs) Spatial pixels 10x binned (~200 m/pixel @ 300 km) |
Between other scheduled observations |
|
Limb scans |
Limb scan measurements (LMBs) Spatial pixels 10x binned; ~200 m vertical sampling |
2 orbits every 2 months |
|
Mapping (selected wavelengths) |
Nadir-pointed |
Multispectral survey (MSP or MSV) 73/74 or 94/94 selected channels, spatial pixels 10x binned (~200 m/pixel @ 300 km) |
~80% of Mars |
Multispectral windows (MSW) 73/74 or 94/95 selected channels, spatial pixels 5x binned (~100 m/pixel @ 300 km) |
Select areas plus sampling of seasonal variation at polar cap |
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Hyperspectral survey (HSP or HSV) 262 channels, spatial pixels 10x binned (~200 m/pixel @ 300 km) |
Select areas plus sampling of seasonal variation at polar cap |
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Radiometric Calibration (CAL) |
- |
Observations of onboard integrating sphere |
Daily |
Bias Calibration |
- |
Dark observations at multiple exposure times |
Daily |
Flat-Field Calibration (FFC) |
Nadir-pointed |
Observations of bland regions of Mars |
Every month |
Contents of each type of CRISM observation
Class of observation |
Frame rate, Hz |
Activity |
Pixel binning |
# |
Wave-lengths |
Frames (typical) |
---|---|---|---|---|---|---|
Full resolution targeted (FRT) |
3.75 |
central scan |
1 |
1 |
545 |
390 |
EPF scans |
10 |
10 |
15 |
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dark sets |
1 |
4 |
12 |
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Half resolution short targeted (HRS) |
3.75 |
central scan |
2 |
1 |
545 |
243 |
EPF scans |
10 |
10 |
15 |
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dark sets |
2 |
4 |
12 |
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Half resolution long targeted (HRL) |
3.75 |
central scan |
2 |
1 |
545 |
487 |
EPF scans |
10 |
10 |
15 |
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dark sets |
2 |
4 |
12 |
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Full resolution short (FRS) |
3.75 |
half central scan |
1 |
1 |
545 |
195 |
dark sets |
4 |
12 |
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Along-track oversampled (ATO) |
3.75 |
half central scan |
1 |
1 |
545 |
195 |
dark sets |
4 |
12 |
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Along-track undersampled (ATU) |
3.75 |
half central scan |
1 |
1 |
545 |
195 |
dark sets |
4 |
12 |
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Atmospheric survey (EPF) |
3.75 |
EPF scans |
10 |
11 or 13 |
545 |
15 |
dark sets |
4 |
12 |
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Limb scan (LMB) |
3.75 |
Individual scans |
10 |
variable |
545 |
540 |
dark sets |
same |
12 |
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Tracking optical depth (TOD) |
3.75 |
3-second segments |
10 |
12 |
545 |
12 |
dark sets |
4 |
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Multispectral survey (MSP or MSV) |
15 |
3-minute segments |
10 |
8 |
73/74 or 94/95 |
2700 |
dark sets |
9 |
12 |
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Hyperspectral survey (HSP or HSV) |
15 |
3-minute segments |
10 |
8 |
262 |
2700 |
dark sets |
9 |
12 |
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Multispectral window (MSW) |
30 |
1 3-minute segment |
5 |
1 |
73/74 or 94/95 |
5400 |
dark sets |
2 |
12 |
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Radiometric calibration (CAL) |
1 (VNIR), 1 (IR) |
sphere background |
1 |
2 |
545 |
12 |
sphere frames |
1 |
32 |
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1 (VNIR), 3.75 (IR) |
sphere background |
2 |
12 |
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sphere frames |
1 |
32 |
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1 (VNIR), 15 (IR) |
sphere background |
10 |
2 |
73 |
12 |
|
sphere frames |
1 |
32 |
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1 (VNIR), 30 (IR) |
sphere background |
5 |
2 |
12 |
||
sphere frames |
1 |
32 |
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Bias calibration |
1 |
dark frames, several integration times |
1 |
4 |
438 (IR only) |
10 |
3.75 |
5 |
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15 |
10 |
4 |
55 (IR only) |
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30 |
5 |
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Flat field calibration (only 1 frame rate at a time) (FFC) |
1 |
dark sets |
1 |
2 |
545 |
12 |
3-minute segments |
1 |
180 |
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3.75 |
dark sets |
2 |
12 |
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3-minute segments |
1 |
675 |
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15 |
dark sets |
10 |
2 |
73 |
12 |
|
3-minute segments |
1 |
2700 |
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30 |
dark sets |
5 |
2 |
12 |
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3-minute segments |
1 |
5400 |
CRISM TRDR products have the following file names:
tttnnnnnnnn_mm_aabbbc_TRRv.IMG (with detached PDS label)
where:
ttt = class type
FRT = Full Resolution Targeted Observation
HRL = Half Resolution Long Targeted Observation
HRS = Half Resolution Short Targeted Observation
FRS = Full Resolution Short Observation
ATO = Along-track Oversampled Observation
ATU = Along-track Undersampled Observation
EPF = Atmospheric Survey EPF
TOD = Tracking Optical Depth Observation
LMB = Limb Scan Observation
MSV = Multispectral Survey, lossy compressed
MSP = Multispectral Survey, losslessly compressed
HSP = Hyperspectral Survey, losslessly compressed
HSV = Hyperspectral Survey - VNIR only, losslessly compressed
MSW = Multispectral Window
FFC = Flat Field Calibration
nnnnnnnn = observation ID, unique for the whole CRISM mission, expressed as a hexadecimal number
mm = ordinal counter carried through from the source EDR ID, expressed as a hexadecimal number
aa = type of observation
RA = Radiance
SU = Summary products
IF = I/F
AL = Lambert albedo
bbb = macro #
c = sensor ID
S = VNIR
L = IR
v = version, 0-9, a-z
CRISM TRDR housekeeping files have the following file names:
tttnnnnnnnn_mm_aabbbc_HKPv.TAB (all variables match corresponding TRDR product)
In ODE, TRDR products, with their associated housekeeping files, have the following Product IDs:
TTTNNNNNNNN_MM_AABBC_TRRV