Detailed Guide for Masjed Soleyman Dam¶

This tutorial provides a comprehensive guide to SARvey processing. If you are an advanced user, you can proceed directly to the fast track for advanced users.

Note

This instruction is based on SARvey version 1.0.0 (Strawberry Pie). Newer versions may differ slightly.

Step 1: Before Running SARvey¶

Step 1.1: Download the Data¶

Download the data by running the following commnad in the console:

wget https://zenodo.org/records/12189041/files/SARvey_input_data_Masjed_Soleyman_dam_S1_dsc_2015_2018.zip

Unzip the downloaded file and change the directory.

unzip SARvey_input_data_Masjed_Soleyman_dam_S1_dsc_2015_2018.zip
cd SARvey_input_data_Masjed_Soleyman_dam_S1_dsc_2015_2018

Check the downloaded data using info.py and view.py. For example:

info.py inputs/slcStack.h5

view.py inputs/geometryRadar.h5

Step 1.2: Activate SARvey and Change Directory¶

If you have not installed SARvey, refer to the installation instructions. Activate the SARvey environment:

conda activate sarvey

Ensure SARvey can be called from the console.

sarvey -h

If you see the following command, it indicates that SARvey cannot be called. Ensure it is installed correctly and the conda environment is activated.

command not found: sarvey

Step 1.3: Create a Config File¶

Create a config file, which is a JSON file containing the parameters for sarvey. The config file can be created using the following command:

sarvey -f config.json 0 0 -g

Note: The above command only generates a configuration file. Although step 0 is specified, it will not be executed.

Step 1.4: Modify the config.json File¶

1.4.1. Open the config.json file and check the parameters. The first parameters to specify in the config file are input_path and output_path. For this example dataset, the slcStack.h5 and geometryRadar.h5 files are in the inputs/ directory, which is the default value in the config file. Therefore, you do not need to change it. The output_path should be outputs/ for this example.

{
    "general": {
        "input_path": "inputs/",
        "output_path": "outputs/"
    }
    // other parameters
}

1.4.2. Specify the num_cores. You can check the number of cores on your computer using the following commands.

In Linux, run:

nproc --all

In MacOS, run:

sysctl -n hw.ncpu

It is a good practice to specify a number lower than the number of available cores in the config file.

{
// other parameters
    "general": {
    "num_cores": 5,
    // other parameters
    },
//other parameters
}

Step 2: Running SARvey¶

SARvey consists of five steps as detailed in Multitemporal InSAR processing workflow. You can run all steps by specifying starting step 0 and ending step 4. In this tutorial, however, we will run the steps separately as follows.

When running sarvey, if it finishes normally, you will see a message like the following in the command line:

2024-06-19 11:05:10,305 - INFO - MTI finished normally.

Note

If you encounter an error, first read all the prompts in the console and carefully track all error and warning messages. If the issue is not clear from the console messages, check the log files stored in the directory specified in the config file. If the error persists and you need assistance, sharing the corresponding log file will help.

Step 2.0: Run Step 0 of SARvey: Preparation¶

The first step creates an interferogram network and calculates the temporal coherence for all pixels. Run the following command:

sarvey -f config.json 0 0

In the command line, you will see a list of parameters used by SARvey to run step 0. All parameters that have been changed from the default are indicated:

...
2024-06-19 11:04:28,137 - INFO - Parameter value default
2024-06-19 11:04:28,137 - INFO - _________ _____ _______
2024-06-19 11:04:28,138 - INFO - num_cores 5 <--- 50
2024-06-19 11:04:28,138 - INFO - num_patches 1 1
2024-06-19 11:04:28,138 - INFO - apply_temporal_unwrapping True True
2024-06-19 11:04:28,138 - INFO - spatial_unwrapping_method puma puma
2024-06-19 11:04:28,138 - INFO -
2024-06-19 11:04:28,138 - INFO - ---------------------------------------------------------------------------------
2024-06-19 11:04:28,138 - INFO - STEP 0: PREPARATION
2024-06-19 11:04:28,138 - INFO - ---------------------------------------------------------------------------------
2024-06-19 11:04:28,138 - INFO - Parameter value default
2024-06-19 11:04:28,139 - INFO - _________ _____ _______
2024-06-19 11:04:28,139 - INFO - start_date None None
2024-06-19 11:04:28,139 - INFO - end_date None None
2024-06-19 11:04:28,139 - INFO - ifg_network_type sb <--- delaunay
2024-06-19 11:04:28,139 - INFO - num_ifgs 3 3
2024-06-19 11:04:28,139 - INFO - max_tbase 100 100
2024-06-19 11:04:28,139 - INFO - filter_window_size 9 9
...

After running this step, a sbas directory is created. Inside this directory, you can find the following files:

outputs/
├── temporal_coherence.h5
├── ifg_stack.h5
├── ifg_network.h5
├── coordinates_utm.h5
├── config.json
├── background_map.h5
└── pic/
    ├── step_0_temporal_phase_coherence.png
    ├── step_0_interferogram_network.png
    └── step_0_amplitude_image.png

Check the PNG files inside the outputs/pic directory and ensure the amplitude image, interferogram network, and temporal coherence look fine. If you are not satisfied with the interferogram network, you can modify the corresponding parameters in the config.json file and run step 0 again.

Use the following command to plot the interferograms:

sarvey_plot outputs/ifg_stack.h5 -i

This command creates the interferograms as PNG files in the following directory:

outputs/
└── pic/
    └── ifgs/
        ├── 0_ifg.png
        ├── 1_ifg.png
        └── ...

Check the interferograms one by one and ensure they look reasonable. In various interferograms, there are fringes associated with deformation approximately at ranges 100-200, azimuth 40-60.

Step 2.1: Run Step 1 of SARvey¶

sarvey -f config.json 1 1

Outputs of this step are:

outputs/
├── point_network.h5
├── p1_ifg_wr.h5
├── point_network_parameter.h5
└── pic/
    ├── selected_pixels_temp_coh_0.8.png
    ├── step_1_mask_p1.png
    ├── step_1_arc_coherence.png
    ├── step_1_arc_coherence_reduced.png
    ├── step_1_rmse_vel_0th_iter.png
    └── step_1_rmse_dem_error_0th_iter.png

Step 2.2: Run Step 2 of SARvey¶

sarvey -f config.json 2 2

Outputs of this step are:

outputs/
├── p1_ifg_unw.h5
├── p1_ts.h5
└── pic/
    ├── step_2_estimation_dem_error.png
    └── step_2_estimation_velocity.png

Step 2.3: Run Step 3 of SARvey¶

sarvey -f config.json 3 3

Outputs of this step are:

outputs/
├── p2_coh80_ifg_wr.h5
├── p2_coh80_aps.h5
├── p1_aps.h5
├── p1_ts_filt.h5
└── pic/
    ├── step_3_temporal_autocorrelation.png
    ├── step_3_stable_points.png
    ├── selected_pixels_temp_coh_0.8.png
    └── step_3_mask_p2_coh80.png

Step 2.4: Run Step 4 of SARvey¶

sarvey -f config.json 4 4

The results of step 4 of SARvey, including the time series, are stored in the p2_coh80_ts.h5 file. The file is named based on the coherence_p2 parameter in the config.json file.

Step 3: Plot Time Series Results¶

Check the instruction on how to use the sarvey_plot.

sarvey_plot -h

Plot the time series using the following command. Flag -t indicates that you want to plot the time series.

sarvey_plot outputs/p2_coh80_ts.h5 -t

You can visualize velocity and DEM error estimation of second-order points. You can also visualize amplitude, DEM, or temporal coherence as the background. Right-click on any point to see its time series. As you will see in the plot, the density of measurement points on the dam is relatively low. In the next section, you will learn how to modify the config file to increase the density of points.

Step 4: Modify Config File and Rerun SARvey¶

Modify the config.json file and change coherence_p2 from 0.8 to 0.7.

Run steps 3 and 4 using the following command:

sarvey -f config.json 3 4

A new file p2_coh70_ts.h5 is created. You can now visualize this file that has a higher point density.

sarvey_plot outputs/p2_coh70_ts.h5 -t

Note

Be cautious that reducing the value of coherence_p2 too much may include noisy points of low quality in the analysis, potentially leading to poor final results.

You should carefully read the Multitemporal InSAR processing workflow documentation to understand the meaning of each parameter and carefully choose reasonable values. You should also check the details of all parameters using the -p flag in sarvey and decide how to tune them.

sarvey -f config.json 0 0 -p

Step 5: Export to GIS Format¶

Export the data to Shapefiles using the following command:

sarvey_export outputs/p2_coh70_ts.h5 -o outputs/shp/p2_coh70_ts.shp

You can open the exported data in any GIS software. If you use QGIS, you can use the PS Time Series Viewer plugin to draw the time series.

Step 6: Validate Your Results¶

You can download a copy of the final SARvey products from this link. Use these files to compare your results and ensure everything worked correctly.

Detailed Guide for Masjed Soleyman Dam¶

Step 1: Before Running SARvey¶

Step 1.1: Download the Data¶

Step 1.2: Activate SARvey and Change Directory¶

Step 1.3: Create a Config File¶

Step 1.4: Modify the config.json File¶

Step 2: Running SARvey¶

Step 2.0: Run Step 0 of SARvey: Preparation¶

Step 2.1: Run Step 1 of SARvey¶

Step 2.2: Run Step 2 of SARvey¶

Step 2.3: Run Step 3 of SARvey¶

Step 2.4: Run Step 4 of SARvey¶

Step 3: Plot Time Series Results¶

Step 4: Modify Config File and Rerun SARvey¶

Step 5: Export to GIS Format¶

Step 6: Validate Your Results¶

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