Carolina R SV

MSc Student 

Earth & Planetary Sciences Univeristy of Western Ontario 


  • Before, during and after Christmas break...

    Hey guys, 

    Happy New Year 2019! 

    It has been over a month since I've updated this blog. Today I am going to talk a bit of what I've done this past month which include: my annual evaluation report, Christmas break in Puerto Rico, LPSC abstract, and chapter 1 of my MSc thesis.

    Before leaving to my wonderful island Puerto Rico to spend my Christmas break in warm temperatures, I presented my annual evaluation report to Catherine and Livio. One year have passed since I moved to this foreign country all alone, with a goal in my mind, getting my MSc degree in Planetary Science. It took me about 4 to 5 months to understand the code that I needed to use to process my data, and a bit more to understand the concept and goal of my research project. I even thought I was not going to be able to do it. I also thought it was too much for me and that I was not smart enough to be here. And there I was, one year later, presenting my annual report at Neish's office. WOW! I was so proud of myself that day. I even had results to show and everything.  At the end, I recieved feedback of my work, one of them regarding the introduction of my thesis which I am currently working on. However, before working on chapter 1, I needed to write my LPSC abstract, and before doing that, I was going for a 2-week Christmas break with my family in Puerto Rico. 

    Two days after my evaluation report and I was on a plane to my beautiful island Puerto Rico. I could not wait for the sunny days at the beach, to have salty hair and sandy feet. I was so excited to see my family and my dogs, to eat my grandma's food, to listen to the coqui at night and hear the Puerto Rican’s unique accent, to feel the humidity in my skin, to smell the fresh air of my hometown while drinking local coffee at my parent's balcony. I admit, I did clap when the airplane got to Puerto Rico, which is a Puerto Rican tradition in all flights. I used to criticize Puerto Ricans every time they clap after a flight, but this time I'm was the first one clapping. Haha.

    After two amazing weeks in Puerto Rico, I came back to LondON and started working on my LPSC abstract. After many drafts, edits, and comments between myself, Catherine, and Livio, we were finally happy with the last version and submitted it.   Now, after all of this, I was ready to start writing chapter 1 of my thesis, which is slowing going, but going.  

    Finally, I want to show my latest surface roughness values of Martian lava flows plotted with surface roughness values of lava flows from Moon and Earth from Neish et al. 2017. 


    Also, here are some pretty pictures of Puerto Rico! Enjoy :) 


  • Writing writing and more writing ...

    Hi all, 

    This blog is going to be quite short since these past few days I've been spending my time writing my M.Sc. thesis proposal for the seminar course, LPSC abstract, and annual progress report. All of these assignments are due in the next few days. That said, I have not done much of data processing and/or analysis.

    However, I have two new Mars DTMs that I want to show today. The DTM on the left is Bullseye crater. The surface roughness parameters derived from this DTM are going to be compare with the statistics derived from the DTM made by the HiRISE team with SOCET SET.  This comparison is key for this project because it will let us know whether the roughness derived from SOCET SET DTMs is the same as the roughness derived from ASP DTMs. 



    Figure 1:  DEMs of Bullseye crater (left) and Marte vallis (right). 

    Credit: NASA / JPL / University of Arizona

  • Generating HiRISE DEMs: Easy when you know what you're doing. 

    Hi all, 

    Today I am proudly presenting my first two creations of MRO HiRISE DTMs. After many days / weeks of poorly understanding the Ames Stereo Pipeline guide book, I decided to google "Generating HiRISE DEMs using ASP" and surprisingly a YouTube video tutorial came up with the exact name. It is incredible the things you can find nowadays on the internet.  So, I am now "googling" everything, and I have become a better independent student. haha... Anyways, let me show you the basics steps for DEMs generation using ASP. 


    Firstly, you need to download all the Experimental Data Record (EDR) products of the stereopair that you want to process. You will want the EDR products that end with *RED.IMG, which are typically 18 files. This number can vary depending on the stereo pair.  Once you have all the EDR products on your computer, and of course Ames Stereo Pipeline and ISIS3 installed, you may open the terminal in the right directory and start your DEM generation. In the command line you will type:




    Here, you are (a) transforming the HiRISE .IMG to .cub format, (b) calibrating the files using the spacecraft imaging parameters, (c) arraying the channels from the instrument sensor so assemble the whole image, and (d) Fine-tuning alignment of channels and reducing the noise.

    You will need to use the resulting files from the first step to be able to compute the upcoming step. In the command line Type:


    >  FILENAME 


    This step determines the minimum overlap between the stereo pair images, as well as, the worst common resolution between the two images. It also map projects the stereo pairs to identical overlap and resolution. 


    You will need to use the resulting files from the second step of this process to be able to compute the upcoming step, as well as, a "stereo.default" file. In the command line Type:


    > stereo FILENAME 


    Here, the stereo pairs are being processed and triangulated into a point cloud. This step can take up to two days. Be patient. 


    Finally, you will use the resulting file of the previous step to continue your DEM generation. Don’t forget to make a "result" folder. Type:


    > point2dem FILENAME result/name-result-files


    This will convert your point cloud into a DEM as a .tif file with header files. 


    To open your .tif files, you can use QGIS, or Erdas Viewer. I recommend you to use QGIS because you can play more with the DTM. I am using *Mars 2000* as the coordinate system, but I am not completely sure if it is the appropriate one to use.  


    Here I am showing the DTMs in gray and spectral color. Note how easy is to see the changes in elevation in the colourized images. Eventhough, I like the colourized DTMs, I am still  in the search of a better color ramp.  


    Left: ESP_052347_052993_1860  Right: PSP_051882_052383_2040

    Credit: NASA / JPL / University of Arizona


    I also wanted to show a colourized Arecibo radar image from Mars modifed from Harmon et al. [2012]. This is just to point out how neat the volcanic regions look like with the MOLA Shaded Relief map underneath it.  Right now, I am uploading the DTMs in JMARS for a better view of their location. However, these DTMs are located south from Elysium (left image) and Northeast from Olympus Mons (right image). 

    Arecibo radar image of Mars modified from Harmon et al. [2012].

  • Generating DTMs - Not as easy as it seems... 

    Hi all, 


    These past few days I have been using ISIS3 and Ames Stereo Pipeline to generate Mars DTMs. Even though I have the ASP guidebook, it has not been that easy to generate them. Let me tell you that I am somewhat confident with my ISIS3 skills but I'm struggling a little bit using ASP. I started my ASP quest at chapter 3 with a Tutorial for Processing Mars Orbiter Camera Imagery (MOC) and I think I am half way there! 

    Lets go through the steps to see what I have done so far and the complications that I have encountered.

    Tutorial steps:

    3.1 Quick Start 

    * I am 95% certain that Catherine completed this step for me because I do see a "stereo.default"  file in the MOC directory. However I tried the stereo commands myself and apparently there is "no such file or directory" and when I try to make one, it wont let me...  

    This is what I am talking about: 

    ISIS 3> stereo left_input_image.cub right_input_image.cub stereo-output


    ISIS 3> point2mesh stereo-output-PC.tif stereo-output-L.tif

    ISIS 3> point2dem stereo-output-PC.tif


    It seems like the command line does not recognize the "stereo" prompt?*... IDK... I have no idea... 




    3.2 Preparing the Data


    The data set that I am using in this tutorial is a pair of MOC images whose product IDs are M01/00115 and E02/01461, and they are located in the example/MOC directory of the Stereo Pipeline distribution (See following image). 

    From: Ames Stereo Pipeline Guidebook




    3.2.1 Loading and Calibrating Images using ISIS


    * After noticing the the base data directory for ISIS was not properly downloaded, we were able to use the "mocproc" program to convert the files from .imq to .cub files. 



    ISIS 3> mocproc from=M0100115.imq to=M0100115.cub Mapping=NO

    ISIS 3> mocproc from=E0201461.imq to=E0201461.cub Mapping=NO





    3.2.2 Aligning Images 


    Since I have no idea why the command line does not recognize the "stereo" prompt?!*, I managed to do this step using "cam2map" instead of "" and I think it might  have worked. 


    ISIS 3> cam2map from=M0100115.cub

    ISIS 3> cam2map from=E0201461.cub matchmap=true



    Then I compared the boundaries of the two files with the ones given in the tutorial and determined the intersection to use as the boundaries for cam2map:



    ISIS 3> cam2map from=M0100115.cub DEFAULTRANGE=CAMERA \

    MINLAT=34.10 MAXLAT=34.44 MINLON=141.50 MAXLON=141.63


    ISIS 3> cam2map from=E0201461.cub matchmap=true



    * I opened  the files on qview and this is how they look like... 


    The images look weird, shifted... I have no idea if this is the way they are supposed to look like... 




    Apparently at this stage, I can run the stereo program with the map-projected images using the following  prompt:



    ISIS 3> stereo --alignment-method none \

    -s stereo.default.example results/output


    *But again, it seems like the command line does not recognize the "stereo"  prompt?!*.... the command line keep saying "error"....



    This is all that I have gotten so far.... I know that I may have skipped a step and I am not seeing which one it is.. But I bet is right in front of my nose... 






    In other news, 


    Today was our first ever CPSX coffee hour! and it was a SUCCESS!!!! 


    Thanks to all of you that joined us! 


    ....and do not forget to join us for the upcoming CPSX Halloween events.










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