VGR Saturn Archive Evaluation

A. AAREADME.TXT

1. "combined- detached" (3.2 second paragraph should be fixed 

FIXED

2. "found on line" should be "found on-line" (3.2 3rd paragraph)

Not changed. We hyphenate “on-line” when it is used as an adjective.

3. Opened OK on my Mac

4. Wording was clear throughout

5. The discussion brought up these overall organizational/design issues:

a. organization is the same as the compressed data

i. But the constraints of 1988 no longer present (faster CPUs)

ii. This perpetuates errors (wrong targets, etc.)

iii. The satellite names were confused back then
iv. You wind up with duplicates due to Volumes 3 and 4

6. Naming convention issues
a. Convention based upon being the same as compressed data

i. But the constraints of 1988 no longer present
ii. the 'C' was for 'count' but who cares now? Could use that character for file type (CLEANED, GEOMED, etc.)


We have adopted this recommendation for volume organization except that we have retained the “C” in file names. The directory structure is chronological and the new volumes are simply sequential in time.

B. /DOCUMENT

1. VICAR label description documents

a. .html and .text OK

b. .LBL clear and helpful

c. document review is noted but have ITAR issues been addressed? 

We believe ITAR issues have been addressed.

1. PDS DD - did not look at in detail

2. DOCINFO

a. OK - clear and helpful

1. Tutorial

a. Could mention that byte swapping is not necessary if VICAR s/w is processing these VICAR files 

We have inserted a comment to this effect.

b. Section 5.4 1st paragraph says IBIS format is covered in VICAR.HTML. It’s not. 

We have added an additional discussion of the IBIS format.

1. Processing

a. Under (5) RESSAR77, blemish files are referred to as "images". They’re not.

b. Under (6) ADESPIKE, "what images have been changed" should be "What pixels 
have been changed" 

Both of the above have been corrected.

C. VGISS_0004 Volume

1. ERRATA.TXT

a. Are the two column_name examples reversed? 

Fixed.

2. INDEX.TAB and SUMDARKS.TAB look OK

D. VGISS_0031 Volume

1. ERRATA.TXT

a. Are the two column_name examples reversed? 

Fixed.

1. INDEX.TAB looks OK

2. CALIB/CALINFO.TXT looks OK 

Fixed.

E. VGISS_0038 Volume

1. MIPL directory

a. VGRSCF.LBL
i. Format and content of SCF file is unknown. Sorry - FICORGEN is gone along with its SCF file description.

b. FICOR77....LBL files

i. Format and content of FICOR77 files is unknown. Do you want that information?

ii. FICOR77 files are in VAX-format. Do you want unix-format versions?

c. BLEMLOC....LBL files

i. Format and content of blemish file is unknown. Do you want that information?

2. ERRATA.TXT

a. Still no real entries. How about known problems with data corruption, satellite names, etc.?

We have updated ERRATA.TXT with the issues noted. We would be happy to supplement the MIPL directories with the files you mention. This can be part of a future update and can be included in the Jupiter, Uranus and Neptune volumes currently in production.

3. CUMINDEX.TAB

a. EXCEL would only import the first 65536 lines. That makes it part way through 
Volume 28. 

The peer review panel agreed that we would not change the CUMINDEX, which is a file required by the PDS.

b. What was imported looks good

F. Label Review 1. 3419147

a. Basic labels have identical values to those in old image file

b. Found START_TIME, STOP_TIME, S/C CLOCK START COUNT, etc. in the PDS 
DD.

c. How did you get a PIXEL FOV=5.225x10-4 deg (and FOV=.418) for the RAW data? 

This is an approximate value, accurate near the center of these distorted FOVs. This is now explained further in TUTORIAL.TXT.

d. What is REFLECTANCE_SCALING_FACTOR doing in RAW/CLEANED image 
label? Seems like it would be N/A but you’ve got 6.487x10-3 for pixel value to I/F? 

Again, this is an approximate value and is explained further in TUTORIAL.TXT.

e. REFLECTANCE_SCALING_FACTOR is 3.3445x10-4 in CALIB version PDS 
label, but is 1.0 in VICAR label. 

This is the famous Jupiter-Saturn mis-calibration issue. It is noted in ERRATA.TXT and explained in TUTORIAL.TXT.

f. CALIB version shows 16-bits properly

g. GEOMED version shows 1000x1000 properly

h. GEOMED PIXEL_FOV and FOV look right for NAC (WACs look OK, too.)

G. Reseau and blemish removal processing 1. 3419147

a. Used PDS RESLOC.DAT and BLEMLOC files to process PDS RAW file. Processed with local RESSAR77; got 0 differences with PDS CLEANED version

b. BLEMLOC.DAT label says format is undocumented. I can supply the format description. Otherwise OK. Why no .TAB? 

See note above. This is a good point and could be addressed in an update and/or in the Jupiter, Uranus and Neptune volumes in production.

c. RESLOC.LBL looks OK; .TAB looks OK

d. Reseau removal looks identical to that of ancient processed version

H. Dark current files

1. DC1_NA_31_C3465802_06.IMG

a. VICAR complains of bad label 

We have regenerated all dark currents and have not encountered any problems with VICAR reading the labels. We suspect this was a disk drive write error.

b. PDS label looks good. Properly shows 16 bits, but scale factor of 100 is only in 
description, not a keyword 

We have documented this as best we can in PROCESSING.TXT.

1. DC1_NA_31_C3458239_06.IMG

a. VICAR likes label

a. PDS label looks good - 16 bits, but scale factor of 100 is only in description, not a keyword

b. Missing and corrupted data after ~line 480 

We suspect this was a disk drive write error. Apologies.

3. Did not check all other DCs for similar missing data or corruption

I. Radiometric Processing 1. 3419147

a. Image, Cal file, DC file all ran compatibly with local FICOR77

b. Cal file FICOR77_VG1_NA_VIOLET.DAT

i. label shows source was a converted PCDF from IBM format in 1985; from VAX format in 1996 - good

ii. VICAR likes label

a. iii. LBL says format is undocumented. Do you want the documentation? 

Yes. See related comments above.

b. FICOR77 results

i. DC's are averages (not sums) of 6, so used NUMDC=100 to compensate for scaling

ii. Using DC of DC1_NA_31_C3458239_06.IMG & Cal file FICOR77_VG1_NA_VIOLET.DAT with local FICOR77, gives exact match of DNs when using NUMDC=100 and no IOF value. But DC is bad after line ~480. The CALIB version of the image is good, so my processed file doesn't match the CALIB version after that line. CALIB version must have used a better version of the DC than the one archived. 

We suspect this was a disk drive write error. Again, sorry.

J. Geometric Processing

1. 3419147

a. GEOMA.TAB looks and imports to EXCEL OK; .LBL file looks OK

b. CALIB and GEOMA.DAT ran compatibly with local GEOMA

c. Running local GEOMA with CALIB and GEOMA.DAT gives perfect match to GEOMA.IMG

d. Running local GEOMA with reslocs from local storage gives perfect match to GEOMA.IMG

e. Old GEOM'd file (from the ‘90s) is one pixel higher that currently processed version and the GEOMA.IMG version (GEOMA probably got updated)

f. Relocated the reseau marks used for the local GEOMA. Got another perfect match to GEOMA.IMG

Thanks for the thorough testing!