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  1. Today
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  4. Ray Arvidson
    Hi there: Would you please let me know which MTRDR scene you have been examining and I will take a look at the data and spectral plots and then answer your questions. Ray Arvidson PDS Geosciences Node Manager and CRISM Science Team Member
  5. Arpita
    Thankyou John
  6. Yesterday
  7. John Christian
    R/Rc is the ratio of the actual reflectance spectrum to the continuum spectrum (basically a straight line connected over the absorption band). ENVI has a Continuum Removal tool (see https://www.harrisgeospatial.com/docs/ContinuumRemoval.html) which looks to me like it performs this calculation for you. If you start with the M3 reflectance images (files that end in "_rfl.img") and use the Continuum Removal tool, the result should be the ratio R/Rc for each band. Then you can use the Band Math tool to put together the sums needed to calculate integrated band depth. Note: I'm not all that familiar with M3 data processing, so you might want to confirm this is the right approach with someone from the M3 team before using this in any publications.
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  9. Arpita
    Thankyou so much How to calculate R/Rc??
  10. Last week
  11. Feng
    Hi Wladimir, Would you please provide the scenes you worked on so that we can better go through from there? Thanks, Feng
  12. John Christian
    Hi Arpita, Just to confirm, you're looking at the formulas on page 4 of this paper, right? https://pubs.er.usgs.gov/publication/70034937 It looks like those are calculating the band depth (1 - R/Rc) at a number of adjacent bands, then adding them together to get the integrated band depth over a range of wavelengths; the variable 'n' is just used to indicate which bands are used in the calculation. So for the 1 micron integrated band depth, you'd calculate band depth at each of 789 nm, 809 nm, 829 nm, and so on, up to 1309 nm, and then add the results (with a similar calculation for 2 micron integrated band depth, just using different M3 bands in the sum). If you're using ENVI for your analysis, the Band Math tool should be able to help you calculate the band depth for each band that you're looking at, then sum up all of the results. John
  13. John Christian started following Assigning Map Information to PDS Images in ENVI
  14. John Christian John Christian joined the community
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  16. Wladimir Acevedo
    Hi dear community, I'm working primarly with MTRDR products for mineral identification using ENVI 5.3 + IDL with CAT 7.4 coupled and i have some questions: 1.- Why when i visualize the spectral profile for some scene in any pixel the profile shape is essentially the same only with changes on the data value?. Does that mean there's only one dominant phase per scene?. Even when i use the Browse Products and can distinguish more than one phase (colors) the profile for the default image (true color) keeps its form. I don't know if this is a coincidence for the scenes that i've analyzed or there is something wrong on the procedure that i'm following. 2.- It is enough the interpretation with the continuum removed function or the ratioing process is necessary?. I consider that isn't an easy task find an appropiate denominator ROI. I've tried to emulate some examples from the MICA files but i did not get the same results. 3.- About the custom stretching for Browse Products, when is neccesary fix the minimum value distinct to zero?. I understand that the maximum generally must be thw 99th percentile of the histogram, right?. 4.- How must be selected the right summary parameters for the "Custom Products" when the "Browse Products" are not good enough? Any help for any question will be very well received, thank you. -Wladimir
  17. Arpita
    Hi Everyone, I am Working with chandrayaan-1 M3 data and i want to calculate band depth for identify mineral. Plz help me how to calculate band depth and what is the value of n in the formula that is discussed by Mustard et al., 2011.
  18. Feng
    hi Wladimir, I think the only difference between yours and mine is the data ignore value. Since you cannot change -1 to 65535. How about you directly open the .hdr file in NotePad and change -1 to 65535 then save the file? You need close the .img in ENVI otherwise, you are unable to save the .hdr file. Thanks, Feng
  19. Guest
    thank you.good job درب ضد سرقت
  20. Earlier
  21. Wladimir started following ODE - MRO Release 49 Loaded into ODE
  22. June Wang
    June 7th, 2019 - Updated MRO CTX EDR products from August 30th, 2006 to December 1st 2018 (orbits through 57874)
  23. Wladimir Acevedo
    Hi Feng, I have reprocessed the image and still happening the same, even with others products that i have tested too. I have noticed that the data ignore value has changed to -1.0000 but i can't reset the 65535.0 default value. I'll leave you the information of the metadata of the image in case you see something different from yours. Thanks, Wladimir
  24. Feng
    Hi Wladimir, I processed the same data as you did and there is no problem at all (the black img_1 and img_2). Would you please redo it? For your additional question, the answer from the team scientist is: The user will need to look at both the product type and data type to figure out the state of the data – and there are also keywords in the label that indicate the corrections that have been applied. A quick summary – IF TRR3 – top-of-atmosphere apparent spectral reflectance (no corrections) AL TRR3 – surface spectral lambert albedo (photometric and atmospheric corrected via RT modeling) IF TER3 – top-of-atmosphere corrected I/F – CAT-like PHT and ATM corrections (and some other steps) have been applied IF MTR3 – map projected version of the corresponding TER For these correction, you can use the ATP correction function in CAT. Thanks, Feng
  25. erentar
    Thank you so very much sir, you helped a lot! Have a great day!
  26. June Wang started following ODE - MRO Release 49 Loaded into ODE
  27. June Wang
    June 3rd, 2019 - MRO Release 49 Loaded into ODE. - Updated MRO CRISM EDR and CDR products from September 27th, 2006 to February 9th, 2019 - Updated MRO CRISM DDR products from September 27th, 2006 to February 9th, 2019 - Updated MRO CRISM TRDR products from September 27th, 2006 to February 9th, 2019 - Updated MRO raw gravity data products released through May 5th, 2019 - Updated MRO SHARAD EDR products from December 6th, 2006 to October 15th, 2018 (orbits through 57279) - Updated SHARAD Radargram data products released through October 15th, 2018 (orbits through 57279). - Updated MRO MCS EDR, RDR and DDR products from September 15th, 2006 to January 31st, 2019 - Updated MRO HiRISE EDR, RDR, anaglyph and DTM products released through April 27th (Orbit 59772), 2019 Please see ODE Mars Holdings – https://wufs.wustl.edu/ode/odeholdings/Mars_holdings.html
  28. Wladimir started following Basics for CRISM processing with ENVi 5.3 and MRO Release 49
  29. Wladimir Acevedo
    Hi again Feng, I have tried the method that you showed for the wavelenght problem, but when i display the results the whole new image appears in black (img_1) and i don't know how to manage this in order get a right image again. Is this method correct for a browse product image (i.e. R: OLINDEX3. G: D2300, B: BD2500_2)? and how i know what it's the right wavelenght for any of these parameters?. I have used 1.0, 2.3 and 2.5 μm, respectively, based on yout example and looking on the Viviano-Beck et al., 2014 paper. It is right?. Also, when i display the new spectral plot it shows like img_2. What am i doing wrong? In addition to this, i have a question about the atmospheric and photometric correction. Are the TRDR and MTRDR images already corrected?. Thank you again, -Wladimir
  30. Tom Stein
    You can use GDAL to convert the IMG file to a number of formats. I used v2.4. Be sure to use the PDS label (.LBL) file as the input to gdal_translate: gdal_translate -of GTiff 1627MR0083990000801607K00_DRCX.LBL .\1627MR0083990000801607K00_DRCX.tif GDAL is available at http://www.gdal.org/ and you can read more about the gdal_translate command at http://www.gdal.org/gdal_translate.html
  31. erentar
    One last question, how am I supposed to open IMG files? I would normally use gdal_translate but no GIS library was able to process it Update: I can process the ones except for: Mastcam, MAHLI, Mardi
  32. Feng
    Hi Wladimir, The CAT_WAVELENGTH_FILTER in the header files is a numeric code from PDS label (in PDS3 label: "MRO WAVELENGTH_FILTER"). It is used when reading original CRISM data into CAT. When parsing PDS label, the default wavelength array to apply to the data (i.e., the standard re-sampling wavelengths for the appropriate wavelength filter used for the observation). It is most likely a book-keeping value. Thanks, Feng
  33. Jennifer Ward started following MRO Release 49
  34. Jennifer Ward
    Release 49 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.
  35. Wladimir
    Hi Feng, Do you know what this field named "filter" in header_form is used for? Wladimir
  36. Wladimir Wladimir joined the community
  37. Feng
    Hi Wladimir, Your adjustment of the x and y in img_2 is correct. This is also what I did to ignore the non-data or bad bands. The number 65535 is also assigned to the bad bands. That's why you see the two straight lines between 2.5 to 3.0 um. For the problem you mentioned in img_3, you can do the following step to make it work: 1, Add wavelength through Edit ENVI header 2, edit the wavelength of your selected band, for example for D2300: tyep in 2.300 then hit Enter, it will update D2300 wavelength 3, after update wavelength of your selected bands, plot the spectral profile, and change the X range: Please let me know if you have other questions. Thanks, Feng
  38. Akshat Agarwal Akshat Agarwal joined the community
  39. Wladimir Acevedo
    Hi Feng, First of all, thank you for your answer, it solved my first question. Nevertheless, i'm facing a trouble with the spectral profile view (img_1) due to a supposed high value of the data, so i have to manually change the Y axis range to see the spectra correctly (img_2). Why this happens?. because i'm understand that the value of 65535 is for the "wavelenghts" but it seems to interfere on de "data" values even being ignored oh the metadata of the image. Also i could not find a way no ignore some bands like you told me. Or am i misunderstanding? Another question that i have is when a use a "browse product" (i.e. PHY: R=D2300, G=BD2210, B=BD1900), i check the spectral profile appearing like these (img_3) and i don't know how to put the values of the wavelenghts on the X axis to get a coherent profile. If you could help me with these it will be really great. Thank you, -Wladimir
  40. Feng
    Hi Wladimir, For your first question, the trr3 is not map projected. So you will see the rectangle instead of the ones you saw on the paper. To map project the trr3, you can use the CAT map projection function. Or you can download the corresponding MTRDR (which is map projected TRDR) if it is available. I don't understand " additionally it opens inverted so i have to apply a 180° rotation. ". I think the original one is correct and you don't need rotate 180 degree. For your second question, the band 1 with value of 65535 is the non-data band. There are other bands which is bad band, these bad band data can not be used. For the bad band list you shall ignore these bands. For example, the following screenshot shows a symbol before the bad bands: Please let me know if you have any other questions. Thanks, Feng
  41. Wladimir Acevedo started following Basics for CRISM processing with ENVi 5.3
  42. Wladimir Acevedo
    Hi dear community, I'm starting with the CRISM data processing with ENVI 5.3 + IDL + CAT 7.4 but for now i feel a few lost, altough i keep the adventure. In any case, i have a couple of questions (very basics, probably) for the TRDR images from the CRISM map data center. 1.- Why when i open the trr3 images with CAT it appears as a rectangle (img_1) and not compressed or deformed like the images that i've seen in papers or documents? additionally it opens inverted so i have to apply a 180° rotation. 2.- When i open the images the band 1 has a value of 65535.0 (img_2)! and that carries problems when i want to visualize the spectral plot. So, it is recommended to eliminar this band or i'm doing something wrong with the images treatment? Any kind of help will be very useful, since i'm really new on this. Regards, -Wladimir
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