File naming for MER OPGS EDRs and single frame RDRs

EDRs and single frame image RDRs generated by OPGS share the common file naming convention described on this page.

mission specific


Filenames take the pattern consisting of fixed-size fields:

Field scid inst sclk prod site drive seqid eye filt who ver . ext
Position 1 2 3-11 12-14 15-16 17-18 19-23 24 25 26 27 28 29-31

Details of the filename fields are given below.

scid - Spacecraft ID

Position 1, 1 character as the spacecraft ID. Valid values are shown in the table below.

Mission name Rover spacecraft Nominal (Flight) ID Simulated (Ground) ID
MER-A MER-2 "2" "4"
MER-B MER-1 "1" "3"

inst - Instrument

Positions 2, 1 alpha character representing instrument ID, denoting the source MER science or engineering instrument that acquired the data.

inst Meaning
A Alpha X ray Particle Spectrometer (APXS)
B Mössbauer
D Rock Abrasion Tool (RAT)
E Entry, Descent, Landing Camera
F Front hazard Avoidance Camera
M Microscopic Imager
N Navigation Camera
P Panoramic Camera
R Rear Hazard Avoidance Camera
T Mini-Thermal Emission Spectrometer

sclk - Spacecraft clock count

Positions 3-11, 9 numeric characters representing the spacecraft clock count in seconds. Which specific SCLK is used depends on the instrument but is generally expected to be the time the data was acquired. It is not guaranteed that this SCLK match the DVT (Data Validity Time) used for operational data management.

prod - Product type

Positions 12-14, 3 characters as a product type identifier. Values beginning with "E" are generally of type EDR, which is the first order product with no processing applied, such as geometric correction (“linearization”) or radiometric correction. Otherwise, the product is an RDR.

site - Site location count

Positions 15-16, 2 alphanumeric characters representing the site location count. Use of both integers and alphas allows for a total range of 0 through 1295. A value greater than 1295 is denoted by "##" (two octothorpes), requiring the user to extract actual value from label. The valid values, in their progression, are as follows:

  • Range 0 thru 99 - "00", "01", "02"... "99"
  • Range 100 thru 1035 - "A0", "A1" ... "A9", "AA", "AB"..."AZ", "B0", "B1"..."ZZ"
  • Range 1036 thru 1295 - "0A", "0B"..."0Z", "1A", "1B"..."9Z"
  • Range 1296 or greater - "##" (two octothorpes)

Example value is "AK" for value of 120. Note that the '#' character is not valid for PDS archiving and data products with this symbol will not be archived.

drive - Drive location count

Positions 17-18, 2 alphanumeric characters representing drive (or position-within-site) location count. Follows the same format as Site above.


The drive location count is sometimes referred to as "position".

seq - Sequence ID

Positions 19-23, 1 alpha character followed by 4 numeric characters representing the command sequence used to capture this observation.

Valid values for first character (first position) in field
Value Meaning
C Cruise
E Engineering
F Flight software (seq rejected)
G (spare)
K (spare)
M Master (surface only)
N In-situ instrument (APXS, MB, MI)
P PMA and remote sensing instrument (Pancam, Navcam, MI, Mini-TES)
R Rover driving
S Submaster
T Test
W Seq triggered by communications window
X Contingency
Y (spare)
Z SCM sequences


Valid values for integers (positions 2 through 5) in field
Value Meaning
"0000" through "4095" Valid sequence number, commanded by Ground
With "F" in character position  
1000s Commanded by NAV
2000s Commanded by SAPP
3000s Commanded by Fault Protection
4000s Commanded by EDL
With "P" in character position  
0000 through 0499 Misc. imaging setup/parm sequences
0500 through 0999 Unallocated, for future use
1000 through 1499 Hazcam sequences
1500 through 1999 Navcam sequences
2000 through 2899 Pancam sequences
2900 through 2999 MI sequences
3000 through 3999 Mini-TES sequences
4000 through 4095 Misc. PMA actuation sequences (deploy, etc.)

eye - Eye

Position 24 - 1 alpha character representing the instrument configuration, an operational attribute of the Instrument that assists in characterizing the data.

eye Meaning
A 3-banded anaglyph of left, right, right eyes mapped to red, green, blue channels
L Left camera eye
M Monoscopic (non-stereo camera)
N Not applicable (non-image data)
R Right camera eye

filt - Filter

Position 25, 1 alphanumeric character representing a camera spectral filter position. Valid values are 0 (no filter or N/A), C (3-band color), or one of the values in the tables below.

Panoramic Camera filter positions

Filter position Left eye wavelength (bandpass), nm Right eye wavelength (bandpass), nm Application
0 NULL or N/A NULL or N/A NULL or N/A
1 719 (179) EMPTY 440 (25) L: EMPTY, R: blue stereo
2 753 (20) 754 (19) Red stereo
3 673 (16) 803 (20) Geology
4 602 (17) 864 (17) Geology
5 535 (19) 903 (25) Geology
6 483 (27) 933 (24) Geology
7 440 (25) 1001 (28) L: Blue stereo, R: geology
8 440 (20) 880 (20) Solar ND5

Microscopic Imager filter positions

Filter position Camera dust cover state Wavelength (Bandpass), nm
0 NULL or N/A NULL or N/A
1 CLOSED 550 - 700
2 OPEN 400 - 700

who - Producer

Position 26, 1 alpha character representing the data producer.

who Meaning
A Arizona State University
C Cornell University
F USGS at Flagstaff
J Johannes Gutenberg University (Germany)
M MIPL (Multimission Image Processing laboratory), JPL
N NASA Ames Research Center
P Max Plank Institute (Germany)
U University of Arizona
X Other

ver - Version

Position 27, 1 alphanumeric character as the version identifier. The Version number increments by one whenever an otherwise-identical file name would be produced. The valid values, in their progression that excludes “0” altogether, are as follows (non-Hex):

ver Meaning
1, 2, ... 9 1-9
A, B, ... Z 10-35
_ 36 and higher


Not every version need exist, e.g. versions 1, 2 and 4 may exist but not 3. In general, the highest-numbered Version represents the “best” version of that product.

ext - Extension

Position 29-31, 2 to 3 alphanumeric characters denoting the product type.

Valid values for nominal operations products:

IMG Image EDRs / RDRs (ODL-format labeled, may include embedded VICAR)
VIC Temporary image EDR / RDRs with only VICAR label (no ODL-format label)
iv Per-wedge Terrain Mesh RDR in Inventor binary format (no label)
ht Per-wedge Height Map RDR (VICAR label)
rgb Per-wedge Terrain Mesh texture RDR in RGB format (no label)
LBL Detached label in PDS or ODL format
JPG JPEG compressed (no label)
_n.JPG Scaled and JPG compressed, where "n" is "2" for 1/2 scale, "4" for 1/4 scale, or "8" for 1/8 scale (no PDS label).
TIF TIFF format (no label)
PNG PNG format (no label)
TXT Text file associated with Specially-processed files
tar Tar file containing Per-wedge Terrain Mesh vertice tile files

Valid values for non-image products:

QUB Multi-layer spectral cube data
CSV Comma-separated-value text file
DAT Non-imaging instrument data
LBL Detached label in PDS or ODL format
TAB Table data