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Sarah020

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Posts posted by Sarah020

  1. Susan,

     

    Thanks for the advice. I had already had a look at these resources but had not realised that the paper was so closely related to the actual LOLA data. I will have a closer look.

     

    Thank you,

     

    Sarah

  2. Hello,

     

    I'm interested in the roughness of the Moon and am currently using the "LRO-L-LOLA-4-GDR-V1.0", "LDRM_16" surface roughness data. I have read the attached .lbl files describing the data however I'm still a little confused as to how the roughness is measured. Please can someone give me a hand?

     

    My understanding at the minute is that a plane defined by three points ( 3 of the 5 LOLA footprint spot pattern) is compared to the plane fitted to either 5 points (1 LOLA footprint), 10 (2 LOLA footprints) or 15 (3 LOLA footprints). The standard deviation of the three-point plane from the "overall" plane is then converted into a roughness measurement in metres.

     

    I was wondering if my understanding is correct and if not, I'd really appreciate it if someone would be able to explain how the roughness measurement works.

     

    The slope baseline is said to vary from 30-120m and I was wondering where these values came from and how they related to the roughness calculations. Are they the baselines of the respective planes?

     

    Also, the roughness is given in metres, is this the vertical roughness (z-axis) or the number of metres (vertical?) deviation from the plane?

     

    Thanks so much,

     

    Sarah.

  3. Hello,

     

    Thanks so much for your reply. I've had a look at the software you recommended, although I think that I maybe didn't explain very well what I meant. I don't want to view the .IMG, I want to access the data table so that I can plot parts from the file myself. I'm not sure whether this is actually possible, but I was hoping so! So my problem is not really in viewing the image, but in opening the data file itself to view the lists of data. Is this an option?

     

    [For example, one of the files I would like to access is the LOLA GDR Roughness map product data file (ldrm_16.img). ]

     

     

    I'm sorry for knowing so little about this, I'm probably asking a very basic question!

     

    Sarah

  4. Hello,

     

    I'm new to using the PDS node and I am struggling to open the .img files that I have downloaded. I'm able to view the .jp2 images associated with each data set, but not the .img files. I know that they are binary data files but I don't know how to access the data within them. Is there any way of getting them into an ASCII or other numerical based format, eg an x,y,(other variable) format? I'm hoping to analyse the data on a Linux system, so any advice tailored to Linux would be appreciated!

     

    Thank you very much,

     

    Sarah

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