IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
Which SPICE kernels?
adamg
post Nov 14 2021, 01:17 AM
Post #1


Junior Member
**

Group: Members
Posts: 31
Joined: 31-October 19
Member No.: 8699



I see SPICE kernels in two different places:

https://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/
https://naif.jpl.nasa.gov/pub/naif/pds/data...cosp_1000/data/

They don't match up, does anyone know which would be the recommended set to look at?

Many thanks
Go to the top of the page
 
+Quote Post
JohnVV
post Nov 14 2021, 04:57 AM
Post #2


Member
***

Group: Members
Posts: 890
Joined: 18-November 08
Member No.: 4489



as i understand the kernels in the "pds" subdirectory are older

use
https://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/

Go to the top of the page
 
+Quote Post
adamg
post Nov 14 2021, 08:30 AM
Post #3


Junior Member
**

Group: Members
Posts: 31
Joined: 31-October 19
Member No.: 8699



Awesome, thanks.
Go to the top of the page
 
+Quote Post
adamg
post Jan 9 2022, 03:55 PM
Post #4


Junior Member
**

Group: Members
Posts: 31
Joined: 31-October 19
Member No.: 8699



I'm running through the images to figure out what's what and I'm stuck when I get to image N1875522952_1 in the extended_extended set.

The image is taken at spacecraft clock 11875522951.118 (the .LBL file suggests this is 08/06/2017at 09:26 however SPICE suggests 07/06/2017 09:28, I'm using this) and I tried loading the following positional kernels which I picked out as the latest versions of PE,SK and SCPSE types of SPK kernels with .LBL date spans that cover the spacecraft clock time:
170619AP_PE_17166_17258.bsp
170619AP_SK_17166_17258.bsp
200128RU_SCPSE_17126_17158.bsp

When I try to get the position (spice.spkpos('Cassini', et, 'J2000', 'NONE', 'SATURN')) I get the following message suggesting I'm not loading the right position kernels.

================================================================================

Toolkit version: CSPICE66

SPICE(SPKINSUFFDATA) --

Insufficient ephemeris data has been loaded to compute the position of -82 (CASSINI) relative to 699 (SATURN) at the ephemeris epoch 2017 JUN 07 09:28:08.127.

spkpos_c --> SPKPOS --> SPKEZP --> SPKGPS

================================================================================

What SPK kernels would you expect for this time point?

Just for completeness the other kernels I'm using are (though I probably only need LSK and SCLK for this query):
LSK (leap seconds) : naif0012.tls.pc
SCLK (spacecraft clock) : cas00172.tsc
PCK (planetary constants) : cpck15Dec2017.tpc
FK (reference frames) : cas_v39.tf
IK (instrument geometry) : cas_iss_v10.ti [Imaging Sub System only]

Many thanks


Adam
Go to the top of the page
 
+Quote Post
adamg
post Mar 12 2022, 11:33 PM
Post #5


Junior Member
**

Group: Members
Posts: 31
Joined: 31-October 19
Member No.: 8699



I'm perhaps asking too soon but I'm seeing the artifacts on the attached image of about code 500 and 0. I tried all the endian-ness and signed-ness but this is the least bad of them.

I was just wondering if anyone else had made the same mistake as me?

Many thanks


Adam

This image is from the label file https://pds-imaging.jpl.nasa.gov/w10n/cassi...592133518_1.LBL
and is named N1592133518_1.IMG
the vicar header is below and there is only one segment per line:
{'LBLSIZE': '3216', 'FORMAT': 'HALF', 'TYPE': 'IMAGE', 'BUFSIZ': '20480', 'DIM': '3', 'EOL': '0', 'RECSIZE': '536', 'ORG': 'BSQ', 'NL': '256', 'NS': '256', 'NB': '1', 'N1': '256', 'N2': '256', 'N3': '1', 'N4': '0', 'NBB': '24', 'NLB': '1', 'HOST': 'MAC-OSX', 'INTFMT': 'HIGH', 'REALFMT': 'IEEE', 'BHOST': 'SUN-SOLR', 'BINTFMT': 'HIGH', 'BREALFMT': 'IEEE', 'BLTYPE': 'CAS-ISS4', 'PROPERTY': 'COMPRESSION', 'ANTIBLOOMING_STATE_FLAG': 'OFF', 'CALIBRATION_LAMP_STATE_FLAG': 'N/A', 'DELAYED_READOUT_FLAG': 'NO', 'DETECTOR_TEMPERATURE': '-89.3184', 'EXPOSURE_DURATION': '40.0', 'FILTER_NAME': '(CL1,CL2)', 'FILTER_TEMPERATURE': '0.248629', 'FLIGHT_SOFTWARE_VERSION_ID': '1.4', 'GAIN_MODE_ID': '29 ELECTRONS PER DN', 'INSTRUMENT_DATA_RATE': '365.568', 'INSTRUMENT_MODE_ID': 'SUM4', 'LIGHT_FLOOD_STATE_FLAG': 'ON', 'METHOD_DESC': 'ISSPT2.6.6;Saturn-Rings;ISS_072RI_SPKHRLPDF001_PRIME_2', 'OPTICS_TEMPERATURE': '(0.627499,1.90571)', 'PREPARE_CYCLE_INDEX': '0', 'READOUT_CYCLE_INDEX': '13', 'SENSOR_HEAD_ELEC_TEMPERATURE': '2.34917', 'SHUTTER_MODE_ID': 'NACONLY', 'SHUTTER_STATE_ID': 'ENABLED', 'BIAS_STRIP_MEAN': '145.571', 'DARK_STRIP_MEAN': '97.561', 'DATA_CONVERSION_TYPE': '12BIT', 'MISSING_LINES': '0', 'COMMAND_FILE_NAME': 'trigger_6676_2.ioi', 'COMMAND_SEQUENCE_NUMBER': '6676', 'ELECTRONICS_BIAS': '112', 'ORDER_NUMBER': '66', 'PARALLEL_CLOCK_VOLTAGE_INDEX': '9', 'DATA_SET_ID': 'CO-S-ISSNA/ISSWA-2-EDR-V1.0', 'DESCRIPTION': 'N/A', 'IMAGE_MID_TIME': '2008-166T10:40:49.626Z', 'IMAGE_NUMBER': '1592133518', 'IMAGE_OBSERVATION_TYPE': 'SCIENCE', 'IMAGE_TIME': '2008-166T10:40:49.646Z', 'INSTRUMENT_HOST_NAME': 'CASSINI ORBITER', 'INSTRUMENT_ID': 'ISSNA', 'INSTRUMENT_NAME': 'IMAGING SCIENCE SUBSYSTEM NARROW ANGLE', 'MISSION_NAME': 'CASSINI-HUYGENS', 'MISSION_PHASE_NAME': 'TOUR', 'OBSERVATION_ID': 'ISS_072RI_SPKHRLPDF001_PRIME', 'PRODUCT_CREATION_TIME': '2008-167T02:39:52.000', 'PRODUCT_ID': '1_N1592133518.118', 'PRODUCT_VERSION_TYPE': 'FINAL', 'SEQUENCE_ID': 'S41', 'SEQUENCE_NUMBER': '1004', 'SEQUENCE_TITLE': '--', 'SPACECRAFT_CLOCK_CNT_PARTITION': '1', 'SPACECRAFT_CLOCK_START_COUNT': '1592133518.108', 'SPACECRAFT_CLOCK_STOP_COUNT': '1592133518.118', 'START_TIME': '2008-166T10:40:49.606Z', 'STOP_TIME': '2008-166T10:40:49.646Z', 'TARGET_DESC': 'Saturn-Rings', 'TARGET_LIST': 'N/A', 'TARGET_NAME': 'SATURN', 'EARTH_RECEIVED_START_TIME': '2008-166T23:12:32.754Z', 'EARTH_RECEIVED_STOP_TIME': '2008-166T23:12:35.797Z', 'EXPECTED_PACKETS': '64', 'MISSING_PACKET_FLAG': 'NO', 'RECEIVED_PACKETS': '46', 'SOFTWARE_VERSION_ID': 'ISS 11.00 05-24-2006', 'TELEMETRY_FORMAT_ID': 'S&ER5', 'EXPECTED_MAXIMUM': '(3.95186,69.7116)', 'INST_CMPRS_PARAM': '(N/A,N/A,N/A,N/A)', 'INST_CMPRS_RATE': '(6.95652,4.85864)', 'INST_CMPRS_RATIO': '3.2931', 'INST_CMPRS_TYPE': 'LOSSLESS', 'VALID_MAXIMUM': '(6250,4095)', 'TASK': 'COPY', 'USER': 'diehl', 'DAT_TIM': 'Mon Mar 16 16:39:55 2009'}
Attached thumbnail(s)
Attached Image
 
Go to the top of the page
 
+Quote Post
JohnVV
post Mar 13 2022, 12:25 AM
Post #6


Member
***

Group: Members
Posts: 890
Joined: 18-November 08
Member No.: 4489



isis4 is importing the file file
Attached Image


there is a lot of noise in the image . Noise that i would remove using Gmic ( after exporting to a tiff )

Go to the top of the page
 
+Quote Post
adamg
post Mar 13 2022, 11:06 PM
Post #7


Junior Member
**

Group: Members
Posts: 31
Joined: 31-October 19
Member No.: 8699



Thankyou for sending a reference, in the end I tracked it down to me being a byte off so the upper word for each pixel was for the pixel before.

Once I got it working I don't see the noise that you have so I think the underlying image is clean.

Thanks again.


Adam
Attached thumbnail(s)
Attached Image
 
Go to the top of the page
 
+Quote Post
adamg
post Mar 16 2022, 10:35 PM
Post #8


Junior Member
**

Group: Members
Posts: 31
Joined: 31-October 19
Member No.: 8699



I swapped out the WAC red channel for a NIR and the blue for Violet and get the attached image that shows the rings up. I saw some mention of the reflective material identification in the Porco paper but not much. Is there a reference for what each material might give off?

Thanks


Adam
Attached thumbnail(s)
Attached Image
 
Go to the top of the page
 
+Quote Post
adamg
post Mar 30 2022, 09:21 AM
Post #9


Junior Member
**

Group: Members
Posts: 31
Joined: 31-October 19
Member No.: 8699



Thought I'd try out the moon images to set the filter balances. I tried a difference image between LUNAR_SCIENCE (CL1,UV3) and 0.8*(CL1,IR1) and get the attached, the white spots are interesting and show more detail than just the brightness.

A linear scaling doesn't get a flat difference over the moon surface and adding an offset just falls out into a constant, I'm guessing there's some non-linearity I'm missing...
Attached thumbnail(s)
Attached Image

 
Go to the top of the page
 
+Quote Post

Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 29th March 2024 - 03:46 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member.