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Mr. Singh, TB values are found in column 24 of Diviner RDR data products (column header "tb"). The channel number is located in column 18 (column header "c"). You can get TB values strictly from channel 9 by selecting only column 24 data where column 18 is equal to 9. You then can apply your formula to these values. Alternatively, Diviner GCP products have "Bolometric average calibrated brightness temperature (K)" noted in column 11, for a given longitude and latitude noted in columns 1 and 2 respectively. If you can explain what you mean by "Zonal mean temperature" I'd be happy to help you with that as well.
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Mr Singh joined the community
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You mean emissivity of that channel ? Also, I have a question like if I want to convert TB to Bolometric temperature than how will I do that in RDR ? . I am using ArcMap. How will I convert it to bolometric brightness temperature for channel 9 only . I have the formula but don't know how to implement ? Another question about Zonal mean temperature ? It refers to zonal mean as if for certain range of lat , long ?
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Some users of LRO Diviner data have asked why there are some data products with negative temperature values. For example: "I'm exploring the temperature data of the Diviner, I have downloaded TB (Brightness Temperature) data for 6,7,8, and 9 channels and I found negative values (in K) in a few of the images after conversion (TB= (DN * scaling factor) + Offset). This negative value is not possible in K, I'm unable to understand this." Answers from Diviner team members: "The shorter wavelength channels are noisy at low temperatures. Each channel has a minimum temperature below which it becomes noisy. These minimum temperature cutoffs go down with longer wavelength channels, so channels 8 and 9 are really the only ones that return useful data in the PSRs. When the channel gets below this minimum temperature, it starts returning negative radiance values. This would explain why channel 4 is giving you negative temperatures, while channel 9 does not. I've attached the Supporting Material from the Paige et al 2010 Science paper [see attachment Paige.SOM.pdf]. The table gives the minimum temperatures for the IR channels (3-9)." (Dr. Jean-Pierre Williams, UCLA, 2019-03-11) "The negative temperatures are actually "good" data. When the net signal at the detectors after calibration gets close to zero, Diviner records both small positive and small negative radiances. When the negative radiances are turned into brightness temperatures, they are reported as brightness temperatures. Zero-ing out the negative radiances would be completely inappropriate, because it is possible to pull signal out of the noise by averaging. You should see more negative temperatures in the shorter wavelength channels (3-6), as well as all channels in the coldest places near the poles. When the thermal emission from the moon is so small that there is no measurable signal, there's a 50% probability that a small negative signal will be measured. We convert these to brightness temperatures, and flag them as negative brightness temperatures, with the understanding that negative temperatures are not possible. In isolation, you can't convert negative temperatures into meaningful temperatures. What we generally do is pick a threshold below which all temperatures should be ignored. This will vary depending on which Diviner channel you are using." (Dr. David Paige, UCLA, 2020-03-24) Paige.SOM.pdf
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March 20th, 2020 - LRO Release 41 has been loaded into ODE. Updated LAMP EDR and RDR products from July 6th, 2009 to December 15th, 2019 Updated LEND EDR_SCI, EDR_HK, RDR_RSCI, and RDR_CHK products from June 18th, 2009 to December 14th, 2019 Updated LEND RDR_DLD and RDR_DLX products from June 27th, 2009 to September 14th, 2019 Updated Diviner EDR and RDR products from July 5th, 2009 to December 16th, 2019 Updated LROC EDR, CDR and RDR products from June 30th, 2009 to December 3rd, 2019 Loaded Mini-RF new Version 3 Bistatic radar data products (EDR, RDR, and DDR) from January 28th, 2019 to June 13th, 2019 Updated LOLA EDR products from June 18th, 2009 to January 22nd, 2020 Updated LOLA RDR products from July 13th, 2009 to January 22nd, 2020 Updated LOLA RDR query tool database from July 13th, 2009 to January 22nd, 2020 Updated Diviner RDR query tool database from July 5th, 2009 to December 16th, 2019 Please see ODE Lunar Holdings - https://wufs.wustl.edu/ode/odeholdings/Moon_holdings.html
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March 19th, 2020 - Updated MRO SHARAD EDR and RDR products from ASI for MRO Release 52 through August 17th, 2019 (orbits through 61208)
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hamidreza joined the community
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MRO SHARAD raw and derived data from the ASI (Italian Space Agency) SHARAD Ground Operations Center are released covering the period May 12 through Aug. 17, 2019 (MRO Release 52). The SHARAD team will now be delivering derived data (RDRs) concurrent with MRO releases. The remaining backlogged RDR data from releases 48-51 will be delivered in the near future. See ERRATA.TXT for details. The data are available on the PDS Geosciences Node's SHARAD page.
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Creating an RGB image from MER and Phoenix data
Tom Stein commented on Christina Kreisch's blog entry in Using the Analyst's Notebook
Hi Dane - You are correct...the Analyst's Notebook has changed a lot over the past 8 years. The procedure is largely the same, although the resulting image is downloaded rather than popped open, as you say. It is important to note that the RGB is created using a simple algorithm that performs a 2% linear stretch on the source images and then assigns them to the red, green, and blue channels to make the composite image. Ideally, one would want to perform custom stretches on radiometrically calibrated source images using image processing software such as ENVI. The scene content affects the Notebook's default linear stretch and thus how the simple RGB looks. What is the image you are working with? And how important is it to you to have the custom image pop up in a browser tab vs direct download? -
Dane joined the community
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Creating an RGB image from MER and Phoenix data
Dane commented on Christina Kreisch's blog entry in Using the Analyst's Notebook
I am trying to obtain colour images from monochrome images captured by MERB It seems like the method for obtaining a colour images from available monochrome images has been simplified since this procedure On trying the new system however I have two issues: 1 - Instead of allowing a preview of the colour image system downloads the RGB image 2 -The downloaded image is monochrome Maybe I am misssing something as the procedure is no longer as described here Sorry to trouble you with this... -
Release 23 from the Mars Science Laboratory (Curiosity) mission includes new data for APXS, ChemCam, CheMin, DAN, and SAM. The data are online at pds-geosciences.wustl.edu/missions/msl.
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Release 41 of Lunar Reconnaissance Orbiter data is now online at the Geosciences Node. This release includes new data acquired between September 15 and December 14, 2019, for most data sets. Data can be reached from the Geosciences Node LRO page. The Lunar Orbital Data Explorer allows searching and downloading of LRO data.
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About the data type of the CRISM I/F images
Ray Arvidson replied to Ausiàs R's topic in Using the Spectral Library
You need to find an area in the corrected spectral data cube that looks spectrally neutral and divide your spectrum of interest by the spectrum that looks spectrally neutral. No DDR involved. Ray -
About the data type of the CRISM I/F images
Ausiàs R replied to Ausiàs R's topic in Using the Spectral Library
Hi Ray, First of all I want to thank for your reply, it is really apreciated. You said that: I understand that the area that looks like it and is spectrally neutral means an area that exhibes a constant reflectivity or transmissivity over the electromagnetic spectrum. But, where can I find this kind of surface/area? Is the data that I need on the ddr files of the image? I saw that there are 14 bands on the ddr images. On this document (pages 76-77) it is explained what those bands represents. I'm not pretty sure which band I shoud use, or if any. Once again, thanks for your answer, Ausiàs. -
March 3rd, 2020 - MRO Release 52 Loaded into ODE. - Updated MRO CRISM EDR and CDR products from September 27th, 2006 to November 9th, 2019 - Updated MRO CRISM DDR products from September 27th, 2006 to November 8th, 2019 - Updated MRO CRISM TRDR products from September 27th, 2006 to November 8th, 2019 - Updated MRO raw gravity data products released through October 26th, 2019 - Updated SHARAD Radargram data products released through August 9th, 2019 (orbits through 61097) - Updated MRO MCS EDR, RDR and DDR products from September 15th, 2006 to October 31st, 2019 - Updated MRO CTX EDR products from August 30th, 2006 to August 21st, 2019 - Updated MRO HiRISE EDR, RDR, anaglyph and DTM products released through February 4th (Orbit 63399), 2020 Please see ODE Mars Holdings – https://wufs.wustl.edu/ode/odeholdings/Mars_holdings.html
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March 3rd, 2020 - MEX HRSC new Version 3 map projected data (REFDR3) data have been loaded into ODE - HRSC new Version 3 of map projected RDR data (REFDR3) have been loaded into ODE, with coverage through September 11, 2018 (Orbit 10-18594). See https://wufs.wustl.edu/ode/odeholdings/Mars_holdings.html for a full list of data holdings in ODE.
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About the data type of the CRISM I/F images
Ray Arvidson replied to Ausiàs R's topic in Using the Spectral Library
Hi There: I am the manager of the PDS Geosciences Node and also a CRISM Science Team Member. The I/F data you are using come from the spectral radiance for each band and pixel location divided by the solar spectral irradiance divided by pi. The is a ratio of spectral radiances and the pi converts solar spectral irradiance to spectral radiance. The solar value used is specific for the heliocentric distance when the scene was acquired, i.e., Mars distance relative to he sun. Your I/F spectra, put through the volcano scan correction using CAT, look good. Here is what you are missing. The next step typically is to then divide the volcano scan corrected I/F spectra by a spectrum from the same corrected data for an area that looks like it is spectrally neutral. This removes any instrument artifacts and tends to de-emphasize the ubiquitous basaltic sands and regolith and thus emphasizes what might be unique in terms of mineral signatures for the area of interest. It kind is like in the lab when you use reflectance spectrometers you ratio your data relative to some standard surface. Remember there are no pure outcrops of given minerals on Mars, rather wind mixes things a lot. I hope this note helps. Please ask more questions if needed. Ray Arvidson -
Good afternoon. I'm an undergraduate student of geomatics and remote sensing, and I was trying to use the CRISM images to classify minerals and chemical compounds on the surface of Mars. I collected some information about all the products to use, also I followed the workflow proposed here and I installed CAT on ENVI. I was trying to use a an image of the Jezero Crater data product: frt00005c5e_07_if166j_mtr3, which is projected, atmosferically and geometrically corrected. The data is on I/F which as is explained here, on the FAQs means: Q: What does I/F stand for? A: CRISM is a reflectance spectrometer, and I/F is how reflectance is represented algebraically: I is the energy (actually radiance) observed by the CRISM instrument, and F is the energy (actually solar irradiance) incident at the top of the Martian atmosphere. I/F is a ratio of energies (radiance/irradiance), with some additional scaling so the ratio is unitless. Acording to my knowledge radiance/irradiance=reflectance (unitless), maybe I'm wrong. The case is that I tried to classify the minerals on the image of the Jezero Crater using this library from Viviano et al using the "CRISM RATIOED I/F CORRECTED" spectra but I get wrong or absurd results. I noticed that the spectra of my images is clearly different from the spectra that I find on the Viviano library ratioed i/f. My Spectra always follow this pattern, and never reaches a reflectance of 0.5. Nevertheless on the Viviano library I found spectra like this one of epidote: Why the spectra of my image is so different? Is my data really on reflectance? How can I get real reflectances?
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abbasebrahimi55 joined the community
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Release 52 from the Mars Reconnaissance Orbiter mission includes new data for CRISM, SHARAD, and Gravity/Radio Science. The data are online at pds-geosciences.wustl.edu/missions/mro.
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This bundle contains ASCII tables containing corrected, reduced, and concatenated versions of all available calibrated data from the Apollo 15 and 17 Heat Flow Experiment, along with supporting documentation and source data. These tables are based on other data in the PDS and the published literature, specifically (1) transcriptions of data sent by the original instrument team to the NSSDC and (2) data not archived by the instrument team and recovered much later from ARCSAV tapes. The data here correct several errors in (1), and furthermore place (1) and (2) into a standardized format for ease of use. This bundle was provided by Matthew Siegler (Planetary Science Institute) and Michael St. Clair and Chase Million (Million Concepts). -
If you are attending the Lunar and Planetary Science Conference in Houston next month, please consider stopping by the PDS booth. In addition to answering any questions you have about archiving with PDS, we will also be offering several training sessions you may find beneficial (schedule: https://pds-geosciences.wustl.edu/lpsc2020.html. We will also have multiple PDS-related posters on display Tuesday and Thursday. Hope to see you there!
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February 19, 2020 A new Mercury SHBDR gravity model derived from MESSENGER radio science data are loaded into ODE. Please see below links for more information. https://pds-geosciences.wustl.edu/missions/messenger/rs.htm ODE Mercury Holdings - https://wufs.wustl.edu/ode/odeholdings/Mercury_holdings.html -
February 19th, 2020 - MRO SHARAD RDR (ASI) backlogged data for releases 36-47 loaded into ODE MRO SHARAD derived data from the ASI (Italian Space Agency) SHARAD Ground Operations Center released covering the period May 17, 2015 - April 20, 2018 have been loaded into ODE. These time periods correspond to previous MRO releases 36-47. The SHARAD team is recovering data from deliveries that were missed due to a hiatus in ground operations between June 2012 and March 2013. See file ERRATA.TXT at https://pds-geosciences.wustl.edu/mro/mro-m-sharad-4-rdr-v1/mrosh_1004/errata.txt for more details. Please see ODE Mars Holdings – https://wufs.wustl.edu/ode/odeholdings/Mars_holdings.html
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SHARAD RDR data from the ASI team members have been posted, covering previous MRO releases 36-47 (through April 20, 2018). The team is recovering data from deliveries that were missed due to a hiatus in ground operations. See ERRATA.TXT for details. The data are available on the PDS Geosciences Node's SHARAD page.
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retailcore joined the community
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February 7, 2020 – MRO HiRISE Updates - MRO HiRISE EDR, RDR, DTM and Anaglyph newly released data products through January 4, 2020 (Orbit 62,999) loaded into ODE See https://wufs.wustl.edu/ode/odeholdings/Mars_holdings.html
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Ausiàs R joined the community
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neville13 joined the community
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CRISM MSP data processing sequence.
Rachael Marshal replied to Rachael Marshal's topic in For data users
Thank you very much, Ray. I will contact him. Warm RegardS Rachael -
CRISM MSP data processing sequence.
Ray Arvidson replied to Rachael Marshal's topic in For data users
Rachel: I am a CRISM Team Member and we have processed MSP data. The destriping is really for full resolution data, not so much for multispectral data. One of my graduate students, Thomas Condus, has been processing a lot of CRISM multispectral data. He can provide details as to how he has processed the data. His email is tcondus@wustl.edu. I will mention to him that you might be contacting him via email to ask for advice. It is currently about 7:30 AM CST and he typically comes in around 9 AM. He has helped several other students move through the sometimes complicated processing procedures and avoiding pitfalls in CRISM processing. Ray Arvidson
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