Comments

• Moderator

  MarioSpeedwagon August 3, 2015 at 10:58am

  Well, took 3 shots and then all blank. 

  Even with CHDK disabled, not seeing anything through the viewfinder now. I think I'm going to have to bury the s100 in the backyard today. 
• Moderator

  MarioSpeedwagon August 3, 2015 at 10:47am

  I just don't get why it would start doing this after 40 flights and thousands of pictures if it was a settings/software issue.
  
  I've got the camera taking pictures on the desk right now, I'll let you know what the results look like, but I'm thinking the s100 might have just been through too many landings.
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  Martin Bellomo August 3, 2015 at 10:41am

  If the problem occurs after a some picture the problem may be that your buffer is full.
  The ISO must be fixed. if your camera must calculate iso for every picture it is a time and proccess consuming task, and this can generate illumination variations.
  Set ISO to manual and try it.
• Moderator

  MarioSpeedwagon August 3, 2015 at 10:35am

  I did swap out SDcards and had no change, but I haven't let it run on the ground yet.

  2 things I did notice yesterday when trying 4 more flights:

  The first 20-30 pictures are always normal-the problem starts after that.

  the blank shots all have an ISO of 800, and all of the other exif data is normal/GPS coords are logged. 

  I did find a few shots that had white specks from high ISO, and a few that were partially obscured, I'm guessing from the shutter itself? 
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  Martin Bellomo August 3, 2015 at 9:52am

  Todd.
  The NDVI is a measurement of photosynthetic activity, and is a relative value. one isoleted value means allmost nothing. you must compare with another values on the same field.
  You also need field data to correlate your NDVI measurements with nitrogen content or things like that.
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  Martin Bellomo August 3, 2015 at 9:46am

  Do you make any tests ?
  ie. try same configuration withouth flying. on and off the airplane, low the shutter speed, change the memmory card, try a faster one.
  Do tests like this one at a time and see the results to find the source of the issue.
  As you say, I think is a shutter speed problem, I saw this issue when you send the cammera the order to take a picture before the previous picture end to be saved. Usually you have a buffer. test everithing, and dont trust on the makers performance numbers.
• Moderator

  MarioSpeedwagon August 2, 2015 at 2:12pm

  Has anyone seen this before? Using a canons100 with Kap uav 3.2, and the issue has been getting worse and worse.

  I don't know if it's an issue with shutterspeed or something, but I've been getting more and more solid black spots in the middle of surveys. 

  
• RG July 20, 2015 at 10:18pm

  Hi Keith, I see that MicaSense costs about $6,450/- . Do you find it worth? I am relatively new to NDVI
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  Todd July 20, 2015 at 1:31pm

  Nice Map! Where is a good resource in finding what the highs and lows of each band mean as far as real life application. ie what would .55 on NDVI mean to a farmer?  
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  Keith Geary July 20, 2015 at 1:22pm

  Sorry for the radio silence, but its busy, busy, busy! I wanted to share my first NDVI image using the RedEdge camera from MicaSense;

  Five channels are used at the same time; band 1 = blue, band 2 - green,

  band 3 = red, band 4 = red edge and band 5 = NIR

  Processing is done in the cloud using "Atlas", MicaSense's own services;

  You can produce, RGB composites with 3 bands or band-to-band raster calculations for NDVI / GRVI / NDRE and get a Digital Surface Model too!

  I will post more about this summers work in the autumn / winter, when I have had time to test things out and write up my findings.