What are the MRO CRISM Products? A CRISM Product Primer
CRISM is a complex instrument that produces a wide range of products with a wide range of options. See more details on the instrument here.
The CRISM Software Interface Specification (SIS) is currently being revised to include descriptions of new product types generated using various CRISM observing modes. More information is in this presentation from the CRISM Team, Brief History of CRISM Observing Modes.
CRISM Observing Modes Used
|
Type |
Description |
Data Set |
|---|---|---|
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Targeted Reduced Data Record (TRDR) - Radiometrically calibrated CRISM spectra derived from a raw Experiment Data Record (EDR) product, i.e. from a single observation. A TRDR is either a radiance or I/F product. Spectral radiance is defined as: W / (m2 micrometer steradians) I/F is defined as the spectral radiance divided by the solar spectral irradiance of the Sun at Mars distance divided by p. 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 but at normal incidence. I is defined as: power / area / l / steradians F is defined as (solar irradiance at Mars) / p 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. A radiance TRDR would be MSP000030AE_01_RA214L_TRR1 and an I/F TRDR would be MSP000030AE_01_IF214L_TRR1. |
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Map-Projected Multispectral Reduced Data Record (MRDR) - A multispectral RDR consists of several or more strips of multispectral survey data mosaicked into a map tile. Thus a map tile is constructed from a large number of EDRs. The mosaic is uncontrolled (accepting existing pointing data often resulting in image mismatch at seams within a mosaic). A global pattern of 1964 such tiles has been developed, forming the major data product for multispectral survey observations. The tile contains data in units of I/F extracted from a temporary TRDR, plus Lambert albedo, summary products, and the DDR data used to generate them. So, for every latitude or longitude in an MRDR, there is both an I/F and all the information providing traceability to a companion I/F corrected for atmospheric, photometric, and thermal emission effects. The MRDRs also include text files having information on the wavelength of the layers of the Lambert albedo and I/F multiband images and on the SPICE metakernels used for map projecting the image data. |
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Targeted Empirical Record (TER) - The TER spectral product is a spatially reconciled (VNIR and IR; S- and L- detector), full spectral range I/F targeted observation central scan image cube in the IR (L-detector) sensor space that has been corrected for geometric, photometric, atmospheric, and instrumental effects. The TER product set includes a hyperspectral image cube in units of corrected I/F (IF), spectral summary parameters (SU) derived from the corrected spectral reflectance data, residual noise remediated refined spectral summary parameters (SR), browse products (BR) derived from the refined spectral summary parameters, data processing information maps (IN), and a text table that lists wavelength information (WV) for the spectral image cube. All of the image cubes are 32-bit real, with the exception of the browse products which have been byte-scaled (8-bit). |
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Map-projected Targeted Reduced Data Record (MTRDR) - The MTRDR spectral product consists of the TER corrected I/F spectral information after map projection and the removal of spectral channels with suspect radiometry (“bad bands”). The MTRDR spectral product is similar in concept to a local, high-resolution map tile comparable to an MRDR, but at ~12 or ~6 times higher spatial resolution with hyperspectral sampling. The MTRDR product set includes a hyperspectral image cube in units of corrected I/F (IF), spectral summary parameters (SU) derived from the corrected spectral reflectance data, residual noise remediated refined spectral summary parameters (SR), browse products (BR) derived from the refined spectral summary parameters, data processing information maps (IN), a map projected version of the associated IR DDR (DE), and a text table that lists wavelength information (WV) for the spectral image cube. All of the image cubes are 32-bit real, with the exception of the browse products which have been byte-scaled (8-bit). |
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Limb Data Record (LDR) - The LDR accompanies each observation scanned across Mars' limb, and includes information on the tangent height of each pixel above Mars' surface and photometric angles to analyze the measured radiances. |
Additional CRISM Products – These products are used for creating the primary science products. Please see the SIS for more information.
|
Type |
Description |
Data Set |
|---|---|---|
|
Experiment Data Record (EDR) - Consists of raw, uncalibrated CRISM spectra from a single observation received from the spacecraft. |
MRO-M-CRISM-2-EDR-V1.0 (same directory as the CDR Data Set) |
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Derived Data Record (DDR) - Contains pointing and other ancillary information. DDRs represent geometric information, indexed to the wavelength bands of EDRs and TRDRs that are closest to 610 nm (VNIR) and 2300 nm (IR) |
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Calibration Data Records (CDR) – Calibration data used to generate radiance or radiance/solar irradiance (I/F) values in a TRDR from an EDR. |
MRO-M-CRISM-4/6-CDR-V1.0 (same directory as the EDR Data Set) |
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Ancillary Data Records (ANCILL) – EDR processing tables |
part of the CDR Data Set |
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Validation Resports (VALREP) - Contains the results of the comparison between every EDR and frame-by-frame predictions of the commanded instrument state. |
part of the EDR Data Set |
CRISM is a gimbaled instrument capable of both tracking a target and nadir-pointed observations. CRISM operates in several observing modes during the primary science orbit. In order to understand a particular CRISM product, you should be aware of the observing mode that generated the product. Please see the SIS for more information as well as additional ancillary products, validation reports and browse products.
|
Mode |
Pointing |
Description |
Desired Covers |
|
Targeted |
Tracking as shown, once per target |
Full resolution Spatial pixels unbinned for target – 18 m/pixel @300 km, 10x binned for EPF Half resolution short Spatial pixels 2x binned for target - 36 m/pixel @300 km, 10x binned for EPF; same swath length as above Half resolution long Spatial pixels 2x binned for target - 36 m/pixel @300 km, 10x binned for EPF; twice swath length as above Full resolution short Spatial pixels unbinned for target - 18 m/pixel @300 km; half swath length as above Along-track oversampled Spatial pixels unbinned for target - 18 m/pixel cross-track, up to ~3 m/pixel downtrack; half swath length as above Along-track undersampled Spatial pixels unbinned for target - 18 m/pixel cross-track, 36 m/pixel downtrack; half swath length as above |
1000's of targets |
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Atmospheric (EPFs) |
Tracking as shown, but only center of target measured |
Spatial pixels 10x binned (~100 m/pixel @300 km) |
9° lon. x 22° lat. Grid every ~36° of Ls (3 non-contiguous days of EPFs) |
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Multispectral |
Nadir-pointed |
Multispectral survey Selected channels, spatial pixels 10x binned (~200 m/pixel @300 km) |
=80% of Mars |
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Multispectral windows 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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Radiometric Calibration |
- |
Observations of onboard integrating sphere |
Daily |
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Bias Calibration |
- |
Dark observations at multiple exposure times |
Daily |
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Flat-Field Calibration |
Nadir-pointed |
Observations of bland regions of Mars |
Every month |
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Lamp Inter-calibration |
- |
Full resolution observations of onboard integrating sphere and lamps, alternating sides |
Every month |
Product Naming Scheme - EDR, DDR, and TRDR:
The file naming convention for EDR, DDR, and TRDR products is as follows.
(ClassType)(ObsID)_(Counter)_ (Activity)(SensorID)_(Filetype)(version).(Ext)
where:
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)
MSS (Multispectral Survey, lossy compressed)
MSP (Multispectral Survey, losslessly compressed)
MSW (Multispectral Window)
CAL (Radiometric Calibration)
FFC (Flat Field Calibration)
ICL (Calibration source intercalibration)
STO (Star Observation)
FUN (Functional test)
UNK (no valid EDRs within observation that indicate class type)
ObsID = nnnnnnnn, - Observation ID, unique for the whole CRISM mission, expressed as a hexadecimal number
Counter= nn, a monotonically increasing ordinal counter of EDRs from one Observation ID, expressed as a hexadecimal number
Activity = for an EDR, type of observation, e.g.
BI### – Bias measurements / Macro#
DF### – Dark field measurements / Macro#
LP### – Lamp measurements / Macro #
SP### – Sphere measurements / Macro #
SC### – Scene measurements / Macro #
T1### – Focal plane electronics test pattern 1 / Macro #
T2### – Focal plane electronics test pattern 2 / Macro #
T3### – Focal plane electronics test pattern 3 / Macro #
T4### – Focal plane electronics test pattern 4 / Macro #
T5### – Focal plane electronics test pattern 5 / Macro #
T6### – Focal plane electronics test pattern 6 / Macro #
T7### – Focal plane electronics test pattern 7 / Macro #
UN### – Instrument configuration does not match macro library / Macro #
for a TRDR, type of product, e.g.
RA### – Radiance / Macro#
SU### – Summary Products / Macro #
IF### – I/F / Macro #
AL### – Lambert albedo / Macro #
for a DDR, type of product, e.g.
DE### – Derived product / Macro#
Sensor ID = S or L (or J=joint for an MTRDR)
Filetype = EDR, DDR, or "TRR" for TRDR, "RTR" for resampled TRDR
Version = 0, 1,...,9, a, ..., z Ext = IMG or TAB
Product Naming Scheme - MRDR:
The file naming convention for MRDR products is as follows.
(Tile)_(ProductType)(Subtype)_ (CLat)(Hemisphere) (CLon)_(Resolution)_version.(Ext)
where:
Tile = Tnnnn, tile number with tile 0000 at the south pole, increasing sprialing northward
Product Type = "MRR" for MRDR
Subtype of product, e.g.
IF - I/F
AL - Lambert albedo
SU - Summary Products
DE - Derived Products for I/F
DL - Derived Products for Lambert albedo
SP - List of observation IDs and SPICE metakernels
WV - List of wavelengths and wavelength ranges of radiance and I/F images
CLat = nn, Planetocentric latitude of tile center
Hemisphere = #, N or S for north or south latitude
CLon = nnn, East longitude of tile center
Resolution = nnnn, in map-projected pixels per degree, e.g. 256 pixels per degree
version = 0, 1,..., 9, a,..., z
Ext = IMG or TAB
Product Naming Scheme - TER/MTRDR:
The file naming convention for TER/MTRDR products is as follows.
(ClassType)(ObsID)_(Counter)_ (Activity)(SensorID)_(Filetype)(version).(Ext)
where:
ClassType =
FRT (Full Resolution Targeted Observation)
HRL (Half Resolution Long Targeted Observation)
HRS (Half Resolution Short Targeted Observation)
ObsID = nnnnnnnn, Observation ID, unique for the whole CRISM mission, expressed as a hexadecimal number
Counter = nn, the ordinal counter carried through from the source EDR, expressed as a hexadecimal number
Activity = for a TER/MTRDR, type of product, e.g.
IFnnn – Corrected I/F / Macro #
SUnnn – Spectral summary parameters / Macro #
SRnnn – Refined spectral summary parameters / Macro #
REnnn – Data processing residual maps / Macro #
DEnnn – Derived data product / Macro #
WVnnn – Wavelength information for the I/F image / Macro #
A prefix of “BR” in the Activity portion of the filename identifies the file as a TER/MTRDR Browse Product, in which case it follows the naming convention specified in section 2.3.4.7 of 'CRISM Data Product Software Interface Specification' file.
SensorID = J (for joined S and L)
Filetype = TER (Targeted Empirical Record), or MTR (Map-projected Targeted Record – short for MTRDR)
version = 0, 1,...,9, a, ..., z
Ext =
IMG – Image cube
HDR – Associated ENVI header
LBL – PDS label
Other Product File Name Scheme - Please see the CRISM Data Product SIS(MRDR Product (pdf), TRDR Product (pdf), TER Product (pdf), MTRDR Product (pdf), EDR/CDR Product (pdf), DDR Product (pdf), and LDR Product (pdf)) for information about other product naming schemes.
Product ID Scheme - EDR, DDR, and TRDR
Each CRISM data product of these types will also have a Product ID that is unique within its data set. The Product ID scheme for CRISM EDR, DDR, and TRDR products is as follows (see file naming convention for allowable values for each field):
CCCNNNNNNNN_XX_AAAAAS_TTTV
Where:
CCC = Class Type
NNNNNNNN = Observation ID as a hexadecimal number
XX = Counter within this observation
AAAAA = Activity Type
S = Sensor ID
TTT = Product Type (EDR, DDR, "TRR" for TRDR, "RTR" for resampled TRDR)
V = Product version number
Product ID Scheme - MRDR
The Product ID scheme for the CRISM MRDRs is as follows:
TNNNN_TTTSS_XXDYYY_RRRR_V
Where:
TNNNN = Tile number
TTT = Product Type ("MRR" for MRDR)
SS = Product subtype, i.e., IF, AL, SU, DE, DL, SP, or WV
XX = Planetocentric latitude of tile center
D = N or S for north or south latitude
YYY = East longitude of tile center
RRRR = Map resolution in pixels per degree, e.g. 0256 or 2048
V = Product version number
Product ID Scheme - TER/MTRDR:
The Product ID scheme for the CRISM TERs and MTRDRs is as follows:
CCCNNNNNNNN_XX_AAAAAJ_TTTV
Where:
CCC=Class Type
NNNNNNNN=Observation ID as a hexadecimal number
XX=Counter within this observation
AAAAA=Activity Type
J=Sensor ID
TTT=Product Type (TER, MTR)
V = Radiometric calibration version number
Other Product ID Schemes - Please see the CRISM Data Product SIS (MRDR Product (pdf), TRDR Product (pdf), TER Product (pdf), MTRDR Product (pdf), EDR/CDR Product (pdf), DDR Product (pdf), and LDR Product (pdf)) for information about other Product ID schemes.