PART1: Import external GCP points into SARscape for orbital refinement
https://www.cnblogs.com/enviidl/p/16524645.html
During SAR processing, GCP point files are sometimes added. The control points used in SAR processing are divided into two categories: geometric control points (Geometry GCP) used to correct geographical location and control points (Refinement GCP) used for orbit refinement. .
Orbital refinement control points are used in the following processing steps:
InSAR/DInSAR processing workflow: /SARscape/Interferometry/Phase Processing/4 – Refinement and Re-flattening
Stereo SAR processing workflow: /SARscape/Interferometry/Stereo-Radargrammetry/2 – Shift Refinement and Re-flattening
MAI processing workflow: /SARscape/Interferometry/MAI Processing/2 – MAI Refinement and Re-flattening
SBAS processing workflow: /SARscape/Interferometric Stacking/SBAS/3 – Refinement and Re-Flattening
The conventional method for selecting GCP points for orbital refining is to manually select GCP points on the input file during the orbital refining step, input files, DEM and reference files.
In some cases, users hope to select a GCP from an existing basemap (optical basemap or Google Earth), or generate a GCP file based on existing point coordinates. For example, when measuring surface deformation, users can determine the position of stable points on the optical base map based on their existing experience in the engineering area. So how can the GCP points found on the optical base map be imported into SARscape for orbit refinement? This article takes the SBAS workflow and selects GCPs from Google Earth as an example to introduce the method of selecting GCP points from existing base maps for orbit refinement.
The following operations are performed after the SBAS workflow has completed the connection diagram generation and interference workflow:
First step
, open the kml file of the project area, use tools on Google Earth to locate several GCP points in the project area (the points should be located at locations without deformation, preferably on artificial features with high coherence), and save the locations as is a kmz file.
Second step
: In ArcGIS, convert the kmz file to a shapefile file. The tool is kmz to layer, and then save the layer as a shapefile file.
Note: This method is for reference only, just convert kmz into shapefile.
Note: The above two steps are the operations of selecting GCP points on Google Earth. If the user wants to select GCP points on the optical base map of geographical coordinates, directly generate a shape vector point layer in ENVI or ArcGIS. If there are known xy coordinates of the GCP point, just use the point coordinate file to generate the shape file directly.
Step three:
Convert the shp of the geographical coordinate system obtained in the previous step into a shapefile of the SAR coordinate system in SARscape. Open the /SARscape/Basic/Intensity Processing/Geocoding/Map to SAR Shape Conversion tool.
Input Files:
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Input File: Select the shapefile file of the geographical coordinate system prepared in the previous step;
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Input Reference File: Select the reference data of the SAR coordinate system (in the subsequent orbit refining process, select which image the GCP points will be used on), here select an object pair generated in the interference workflow fint file as reference data;
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Optional Files: Enter the GCP file used for geometric correction, which is not entered here.
DEM/Cartographic System: Enter the reference DEM or select a coordinate system as the reference for the geographical coordinate system. Enter the reference DEM file here.
Step 4:
In the orbit refining step, select the GCP interface and import the slant distance shapefile generated in the previous step to proceed with orbit refining.
On the orbital refining data input panel, enter the project file, click Create GCP, select the input file and reference DEM file, and click Next.
Figure Click Create GCP
On the GCP generation panel, click Load GCPs, select the shapefile file of the SAR coordinate system generated in the previous step, import the GCP points, and check the position of the points on the reference image. If there are GCP points that are not within the image range, delete them. If the imported GCP point number is garbled, just ignore it. You can also add new GCP points manually.
Figure Click Load GCPs to import the GCP point shapefile file of the SAR coordinate system
Note: Some versions do not support the Chinese attribute content in shp. You can delete the corresponding Chinese field in shp and then use it, as shown below:
Figure Edit the attribute table of shp point
Switch to Cartographic System and select the geographic coordinate system: GEO-GLOBAL-GEO-WGS84
Switch to the Export panel, set the path to the output xml point file, and click Finish.
After confirming the input of the generated control point file on the panel, proceed with the orbit refining operation.
PART2: SARscape imports Sentinel 1 data and automatically reads orbit files
https://www.cnblogs.com/enviidl/p/16333401.html
In SARscape, before importing Sentinel data, place the orbit files of the data in the directory specified by the system. The software will automatically read the orbit files of the corresponding data when importing the data, without the need to manually enter them in sequence.
This article operates in SARscape5.6.2 version, and other versions operate the same.
Here’s how to do it:
The first step,
Open the system parameters/SARscape/Preferences/Preferences common. In the system parameters panel, in the Directories and batch file name tab, Sentinel-1 auxiliary directory specifies a path to store the sentinel data track file. Note that the folders are all named in English. . Click OK.
Figure Specify the storage path of the Sentinel data track file in the system parameters
Second step,
Create a new folder under this path, name it: AUX_POEORB, and place the downloaded Sentinel data precision orbit file directly under this path. Precision track files of all time can be placed in this folder and the program will automatically select them.
Note: 1. If you want to use the return track file, you can create a folder named AUX_RESORB and place the return track file in this folder. If you do not use the return track file, you do not need to create this folder;
2. The program will first search for the precision orbit file in the AUX_POEORB file. If there is one, it will be used directly. If not, it will then search for the return orbit file in the AUX_RESORB folder. If the corresponding orbit file is not found in both folders, The program will use the orbit information that comes with the Sentinel 1 data metadata to import;
3. If the data needs to be subjected to interference processing, it is recommended to use precision orbit files when importing.
Figure Place the downloaded precision orbit file in the location specified by the system parameters.
The third step,
Open the menu/SARscape/Import Data/SAR Spaceborne/Single Sensor/SENTINEL-1. On the Data Input File List panel, enter the Sentinel 1 data to be imported. You can enter one scene or multiple scenes at the same time (version 5.6.2 Just enter the compressed package directly).
Figure Sentinel data import interface
After executing the Sentinel 1 data import, if the precise orbit file or regression orbit file of the corresponding data is not found, there will be a corresponding prompt, as shown below.
Figure Prompt that orbit data is not found
Note: If you are using version 5.2.1, in the input data panel, just leave the space below for inputting the track file empty, as shown below:
Figure 5.2.1 version of Sentinel data input interface
PART3: SARScape uses GACOS data
https://blog.csdn.net/qq_41159191/article/details/127453080
1 GACOS data download
GACOS official website
http://www.gacos.net/
Time of insterest (in UTC) time setting
This can be seen in the data name. If the data strips are consistent, then the daily shooting time should be the same, as shown in the red box in the figure below. The number after T is HHMMSS, which is 10 hours, 18 minutes and 43 seconds.
Select binary fileBinary grid
After submission, if there are no errors, this interface will pop up.
2 GACOS data processing
2.1 View data
The downloaded GACOS data is in tar.gz format.
Unzip the data and view the Readme
GACOS tropospheric delay maps are given in a grid binary format (4-byte float little endian, naming
convention YYYYMMDD.ztd).
2.2 Import GACOS
Tool path/SARscape/Import Data/Other Format/GACOS, the help interface will pop up after opening
A reminder pops up, click Yes, and then you can see Import Gacos
Enter the GACOS data and remember to decompress it first, because you can only select data in .ztd and .ztd.tif formats when importing, and the downloaded data is a compressed package file in tar.gz format.
Quick view and export settings
This step is quick and completed immediately
2.3 GACOS used for atmospheric phase delay correction
Tool address:/SARscape/Interferometry/Interferometric Tools/Atmospheric Phase Delay Correction
Input interference pattern fint and slant distance dem (srdem)
Enter the GACOS data of the master and slave images, and be sure to check the date.
Select GACOS in Atmosphere External Sensors in Parameters
export data
2.4 GACOS for elevation correction
For elevation correction, you only need to select the unwrapped file in optional files
Check the atmosphere height correlation flag in parameters to True
By selecting this flag, the algorithm estimates and removes the height-correlated component of the atmosphere from each interferogram, using the “Height-correlation window size [m]” (atmospheric fraction) parameter to define the size of the filter.
3 Use of GACOS in SBAS-InSAR
Tools: /SARscape/Interferometric Stacking/SBAS/2 – Interferometric Process
Instructions:
Import the previously imported GACOS data into the corresponding list. The location of SBAS Interferometric Process is Optional Water Vapor File List.
If you want to use GACOS data, be sure to add the following citation:
Yu, C., Li, Z., Penna, N. T., & Crippa, P. (2018). Generic atmospheric correction model for Interferometric Synthetic Aperture Radar observations. Journal of Geophysical Research: Solid Earth, 123(10), 9202 -9222.
Yu, C., Li, Z., & Penna, N. T. (2018). Interferometric synthetic aperture radar atmospheric correction using a GPS-based iterative tropospheric decomposition model. Remote Sensing of Environment, 204, 109-121.
Yu, C., Penna, N. T., & Li, Z. (2017). Generation of real-time mode high-resolution water vapor fields from GPS observations. Journal of Geophysical Research: Atmospheres, 122(3), 2008- 2025.