Jump to content
PDS Geosciences Node Community

Feng

Members
  • Posts

    34
  • Joined

  • Last visited

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

Feng's Achievements

Newbie

Newbie (1/14)

  1. hi Rochdi, My suggestion is that you merge the S (VNIR) and L(IR) cubes into one and then slice them to what you want. The S cubes and L cubes have minor offsets. To merge them, you have to register one another. And then use attached IDL code to merge them. Following are detailed steps: 1, download the CTX covers the S/L cubes area in ODE (using Geotiff format CTX product) for example using crism trdr (frt0001176e_07) as example: first search frt0001176e_07 product then show result on map, you can see frt0001176e_07 area on the map; select CTX layer; on map display, draw a rectangle to cover this area using "Select Products with Rectangle" tool; download the CTX product in Geotiff format for exmaple (B07_012228_1427_XN_37S039W.tiff) 2, in CAT doing map projection for both S and L cubes 3. register map projected S and L cubes to the CTX product by using "Image Registration Workflow" Manually select tie points (I select 9 tie points ) between CTX and TRDR: 4, rename the attached SL_alignment_v5.txt to SL_alignment_v5.pro and open it in IDL, In IDL interface, click "Run', it will ask you select L cubes (results from step 3) , then select S cubes (results from step 3) and output the merged data. Now you have the data covers from 0.3646 to 4. You can select bands you need to export a subset data. SL_alignment_v5.txt
  2. Hi Rochdi, It shows your CAT is successfully installed (it is under Display Tab, CAT 7.4 not under the toolbox extensions) in the first recording you sent to me. You shall be able to use all CAT function. Please let me know if you have any problems. Thanks, Feng
  3. Hi Rochdi: My timezone is Central Daylight Time (GMT -5). It's fine if we cannot go through virtual meeting. We can fix this issue via email communication. First I want to know several things: What's ENVI version you are using? Are you using Windows or Linux? Would you please check the idl.pref file described in the instruction document? Thanks, Feng
  4. Hi: This is Feng, I am glad to help you on the CAT issue. Based on your description, it seems ENVI doesn't recognized the CAT path. Once CAT is installed successfully, it won't show on ENVI toolbox but will be under the Display tab. We can start a zoom if you have a prefer time to solve this issue. Thanks
  5. Hi: This is Feng, I am glad to help you on the CAT issue. Based on your description, it seems ENVI doesn't recognized the CAT path. Once CAT installed successfully, it won't show on ENVI toolbox but will be under the Display tab. We can start a zoom if you have a prefer time to solve this issue. Thanks, Feng
  6. Hi Ralph, I checked the same frame I processed two weeks ago. It seems I don't have the black strip. What is the value at the black strip when you move mouse on the black strip using cursor value in ENVI? How big is the result file? Would you please resample it to small one and then send it to me with the header file? Thanks, Feng
  7. Hi Ralph, This is caused by ENVI displaying the CRISM 65535 data_ignore_value. The warp image is displaying the big span than the valid data range. To display it correctly, you can modify the histogram stretch. Here are the steps: 1, first check the histogram for three bands value range of the trr3: 2, use "save as" tool under File to output the warped result to specify the data ignore value: 3, then change the output image accordingly: From to: Please let me know if you have any questions. Thanks, Feng
  8. Hi Ralph, i saw the miss-match feature when overlapping CRISM on CTX even projecting them to the same map projection. This is because CTX and CRISM are from two instruments and processed differently. So you may use ENVI image registration to co-register CRISM to CTX to reduce the difference (see image registration workflow in ENVI: https://www.harrisgeospatial.com/docs/ImageRegistration.html). Please let me know if you have any question. Thanks, Feng
  9. Hi Ralph, This is Feng. I will assistant you on this issue.These definitions are in CAT folder: CAT_ENVI -> aux_files -> crism_projection. These are three files in the folder. And you shall copy them to ENVI folder like: C:\Program Files\Harris\ENVI55\IDL87\resource\pedata\user_defined You can check CAT installation guide for more details: step 5 in https://pds-geosciences.wustl.edu/missions/mro/CAT_74_ENVI_5x_Setup_Windows.pdf Please let me know if you have any question. Thanks, Feng
  10. Hi Vidyesh, A data ignore value is a designated pixel value that ENVI should ignore when processing an image or computing statistics. When CAT processing these image, it sets the noData as 65535. If the data ignore value is not set as 65535, when ENVI display these images, it displays the whole data range (i.e. from 0 to 65535). So the input histogram for each color (RGB) is from 0 to 65535, the output display will arrange them from 0 to 255. Since most values data are close to zero end not the 65535 end, it returns 0 (for each color i.e. RGB) on the output display instead of a value between 0 and 255. So ENVI now displayes a image which has R=0, G=0, B=0. which is actual a black image. Hope this helps. Thanks, Feng
  11. Hi Vidyesh, I download these two data and processed the exact same way as you described but didn't find any problem. Your processing looks fine. One thing you may look at is the header file of the stacking image. The blank in your image could be the data_ignore_value in your header. Would you please compare the header file with mines: ENVI description = { Create Layer File Result [Tue Dec 17 09:47:59 2019]} samples = 751 lines = 634 bands = 518 header offset = 0 file type = ENVI Standard data type = 4 interleave = bsq sensor type = Unknown byte order = 0 map info = {MRO Mars Equirectangular [IAU 2000] [-35.00N; -39.88E], 1.0000, 1.0000, -6787.3851, -2187402.8323, 1.8000000000e+001, 1.8000000000e+001, D_Mars_2000_IAU_IAG_custom_sphere_lat35, units=Meters} projection info = {17, 3389570.0, -35.000000, -39.880000, 0.0, 0.0, D_Mars_2000_IAU_IAG_custom_sphere_lat35, MRO Mars Equirectangular [IAU 2000] [-35.00N; -39.88E], units=Meters} coordinate system string = {PROJCS["MRO Mars Equirectangular [IAU 2000] [-35.00N; -39.88E]",GEOGCS["GCS_Mars_2000_IAU_IAG_custom_sphere_lat35",DATUM["D_Mars_2000_IAU_IAG_custom_sphere_lat35",SPHEROID["Mars_2000_IAU_IAG_custom_sphere_lat35",3389570.0,0.0]],PRIMEM["Reference_Meridian",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Equidistant_Cylindrical"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-39.88],PARAMETER["Standard_Parallel_1",-35.0],UNIT["Meter",1.0]]} wavelength units = Nanometers data ignore value = 6.55350000e+004 band names = { Layer (Band 1:frt0001176e_07_if164s_trr3_corr_p.img), Layer (Band 2:frt0001176e_07_if164s_trr3_corr_p.img), ..... Also I am using CAT 7.4 in ENVI 5.5 standard (not classic version) to process data. This may be another difference between us. Please let me know if the problem is still there after you check the header or reprocessed in ENVI 5.5 standard. Thanks, Feng
  12. Hi Wladimir, This is Feng, I will try to answer your questions: Should I obtain the summary parameters and then apply the map projection or it is the opposite? Basically they are identical. For my opinion, I will do map projection then summary parameters since it reserves the summary parameters band name. It is necessary the "ratioing" for the spectra and use the "Flatten summary parameters" option?. I've seen a post where its says that is enough the "Continuum Removed" option Sorry I don't understand this question. I will take the team scientist about this. - How can i obtain a better resolution for the summary parameters image?. I've seen very good resolution images from papers that doesn't look like what I have obtaining (img_1) The summary parameters doesn't change the resolution. For this product, it is 18m/pixel. Here is all CRISM EDR resolution: https://ode.rsl.wustl.edu/venus/pagehelp/quickstartguide/index.html?crism_edr.htm For some Along-track oversampled (ATO) Spatial pixels unbinned for target – 18 m/pixel cross-track, up to ~3 m/pixel downtrack, requires special processing for increased resolution; half swath length as above. For img-1, if you only select one band (BDI1000IR), you can see When I create the summary parameters image the spectra doesn't look like the TRDR pure image because the data values change. Does that mean that I have to use the spectra from the TRDR and the summary parameters image is just like a "color guide" fot the mineral phases? (img_2) Yes. For your attached Img-2, the index is not the wavelength but the summary parameters band: Finally, how can I use the summary parameters properly and elaborate mineralogical maps from they? For the summary parameters, you can read the following paper: Revised CRISM spectral parameters and summary products based on the currently detected mineral diversity on Mars https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2014JE004627 Hope this helps. Thanks, Feng
  13. Hi Wladimir, Would you please provide the scenes you worked on so that we can better go through from there? Thanks, Feng
  14. 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
  15. 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
×
×
  • Create New...