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Yes, I supply the same variable used in the original simple Krige as the Conditioning Features and then add the standard deviation values to the Conditioning Measurement Error field.
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04-25-2018
08:44 AM
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849
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That area has a higher standard deviation due to wildfires in the region and sporadic sampling intervals (every 3 days). Not every site sees every wildfire and they may be missed entirely if samples are not taken on that day. Therefore, trends in that region tend to have higher standard deviation/uncertainty. I'll add to the original post that these are trend values. Sorry if there was any confusion. Thanks for the help!
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04-24-2018
06:41 PM
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2
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849
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I have been using the Gaussian Geostatistical Simulation (GGS) tool to incorporate uncertainty into my final Krige products. The data I'm looking at are trend values of particulate matter, which tend to be highly variable in areas with wildfires such as the Northwest. The first figure shows the initial Simple Krige product along with all of my site values (n = 160). Each site has its own uncertainty, so I have been using conditional GGSs to incorporate that uncertainty (per the conversation here: Kriging input with uncertainties). The second figure shows the mean output after 500 GGSs. What I'm trying to understand is: why do the maximum Krige values shift away from the 0.97 & 0.68 sites (in Idaho and Montana) after running the GGSs? Also, why does Figure 2 show a "hot spot" in a region (over northern Nevada) with almost no data points? I've also attached the standard deviation values at each site (Figure1_standardeviation), if that could be of help. Thank you.
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04-24-2018
04:16 PM
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1060
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Perfect! The process ended in an error so I lowered the number of simulations to 50 and it worked fine. I'll slowly bump up the number of realizations to figure out what my clunky, old work computer can handle. I think it's my computer, not the number of points I have (I only have 160 sites across the contiguous U.S.). Thanks again for you help. I could not have done this without your thoughtful and detailed responses!
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03-02-2018
08:13 AM
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This actually works really well for me. My data points are trend values calculated from daily site data over 20 years. When I calculate the trend, I also calculate standard error of the trend estimate, which is exactly what you're asking for. (Let me know if I'm getting that wrong though). All data at each site is taken by the same instruments and already corrected for so I'm not worried about the instrument-to-instrument error, just the error in my trend estimates. One last thing, my the simulation (using 1000 for Number of Realizations) has been running for about two hours now. Is that usual or should I lower that number? Thanks for all the detail you've provided. It's been invaluable.
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03-01-2018
02:34 PM
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2
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2010
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I am a little unsure about #7 and the meaning of "one standard deviation of measurement error". Is there a formula I could use to calculate this value from mean, standard deviation, standard error, variance, etc.? In #8, size seems to be predetermined when I started adding variables. Should I just leave the size that it computes alone or is there some way I should calculate that separately? Thanks again for you help!
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03-01-2018
12:51 PM
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4
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2010
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My measurement error changes from point to point. Thanks for your help!
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03-01-2018
10:11 AM
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2010
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I have this exact same issue. How do you go about doing this in Geostatistical Analyst? (Yes I do have the extension)
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02-28-2018
03:35 PM
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0
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8
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2010
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