Time Series Analysis Tool - Possible Bug


#1

Hi,

I am using SNAP v.6. I have processed 3 Sentinel-3 OLCI images and I am now checking the temporal profile using the Time Series Analysis tool of SNAP. Everything works fine but I think there is a bug or error when using the "Show average ROI" I click on the icon to define my area (either with a polygon or rectangle) and right after defining the shape SNAP freezes and do not recover so I have to kill the process. This happens both when choosing “average” or “standard deviation”

I have tried both in Linux and Windows and I have got the same issue. Is this a known issue?

M


S3 Time-series problems
Crop monitoring and yield mapping with sentinel 1
SNAP Problem - Time series analysis not working in SNAP 6.0
#2

Is your ROI very large? I noticed that the Time-series analaysis tool requires much RAM. Maybe your system is just exhausted?


#3

It happens even with very small areas. By the way, the show for selected pins or show for all pins does not work neither. Adding pins in the image and selecting those options does not create the static graph that is suppose to appear.

In this image, the pin is located in the image and selected. Any of the two options to show the graph at the pin location works. The line you can see is just the grap at the mouse position when I took the screenshot

M


#4

for me, sometimes it helped to check the filter button, if the correct data is selected.


#5

You mean this filter button?


#6

yes, it helped me in some cases to update the profile.


#7

Right after adding the input images to the tool, I use the filter button to select the band that I want to use to show the temporal profile. Afterwards, checking it again only opens the pop-up window to select another band. + If I try to define a ROI, SNAP freezes so no chance to check it again. Not sure I am getting your point.

M


#8

I haven’t used this particular time series tool. So I haven’t seen this problem before.
This tool was developed for SAR data. It is shipped with the S1TBX.
Maybe it can’t handle spectral data very well. I filed an issue (SITBX-499).


#9

Thanks, I will try with S1 and check if I get the same error.

M


#10

Hi, I am trying to use the tool with Sentinel-1 time-series and I am running to the same problem with both geometry and pins. I am running SNAP V 6.0.


#11

Hi,
I was trying with pins and Sentinel-1 but there is some problem definitely.
Intensity values of my pins are about 0.03-0.05. But when I click on icon “Show for all pins” graph intensity range is fixed from 0 to 100 and no pin-lines are shown (perhaps there is some line at 0-level but it’s hard to tell). If I move cursor over the image again, single line of the cursor-pixel is shown even if the values are close to other pin values.


#12

Hi,
just want to say that I found out the same problem…
This is something very important that needs absolutely to be fixed in the future!
Regards


#13

I never could reproduce the error, it worked for my every time. This is what i did:

  1. Make a stack of SAR images (ENVISAT ASAR in my case)

  2. Open the settings of the time-serires tool and select the stack as an input
    grafik

  3. Move the mouse over an opened image (doesn’t need to be RGB) Make sure this is selected grafik


    (values are uncalibrated in my case, therefore amplitude)

  4. Create pins and give colours in the Pin manager

Sometimes it’s needed that you shortly open and close the settings grafik again or that you click on an opened image view so the graph gets updated.

  1. Digitize an area and select grafik to get its mean or standard deviation.

#14

Is SNAP 6.0 is capable to perform PSInSAR analysis using multiple Image data?


#15

No, SNAP can only be used to prepare the images as an input for StaMPS software which can perform PSI. Please have a look here: About the STaMPS category


#16

Hi,
I wanted to create a temporal profile using time series analysis tool. I have tried the same steps as you did. But am not able to get the plot.


#17

try adding all images separately into the time-series tool instead of a stack. This worked for me all times.


#18

Still the same result has obtained for me.Following steps were done:

  1. Added all images seperately in settings page
  2. Moved the cursor point over the image( but the graph was not obtained)
  3. using rectangle drawing tool an area was selected, then clicked “show average ROI”(Still the graph was not plotted)

#19

I got the problem solved…:grinning: It might be due to the update done to the plugins installed.

Can I visualize the temporal profile of selected areas(for which the shapefiles are already created) using the same tool?


#20

Hi there,

I have the same problem discussed here. Sometimes the time series works well - graph shows both mouse cursor and pins (I was able to get also ROI only couple of times). But sometimes is just stops working and the only thing I get is mouse cursor. I do not see that this discussion came to a solution, did it?

For S1 images it works better, only occasionally it “stops”, but for S2 images I got only the mouse cursor working, not pins. I know it is designed for S1, but if the mouse cursor works also for S2, why shouldn´t also pins work?

In addition, I have never got it working with a stack, only with separated images.

Thank you.