A common architecture for all Sentinel Toolboxes is being jointly developed by Brockmann Consult, SkyWatch and C-S called the Sentinel Application Platform (SNAP).
SNAP全称Sentinel Application Platform,是欧空局开发的卫星数据科学探索通用工具箱。SNAP 为处理、建模和可视化卫星图像提供了一个直观的平台,特别是对于哨兵任务。该软件经过优化,可以处理大量卫星数据。它还有助于处理 SAR 数据,例如来自 Sentinel-1 的数据。
INFO: org.esa.snap.core.gpf.operators.tooladapter.ToolAdapterIO: Initializing external tool adapters
INFO: org.esa.s2tbx.dataio.gdal.GDALVersion: GDAL not found on system. Internal GDAL 3.2.1 from distribution will be used. (f0)
INFO: org.esa.s2tbx.dataio.gdal.GDALVersion: Internal GDAL 3.2.1 set to be used by SNAP.
INFO: org.esa.snap.core.util.EngineVersionCheckActivator: Please check regularly for new updates for the best SNAP experience.
INFO: org.esa.s2tbx.dataio.gdal.GDALVersion: Internal GDAL 3.2.1 set to be used by SNAP.
Usage:
gpt <op>|<graph-file>[options][<source-file-1><source-file-2>...]
Description:
This tool is used to execute SNAP raster data operators in batch-mode. The
operators can be used stand-alone or combined as a directed acyclic graph
(DAG). Processing graphs are represented using XML. More info about
processing graphs, the operator API, and the graph XML format can be found
in the SNAP documentation.
Arguments:
<op> Name of an operator. See below for the list of <op>s.
<graph-file> Operator graph file(XML format).
<source-file-i> The <i>th source product file. The actual number of sourcefile arguments is specified by <op>. May be optional for
operators which use the -S option.
Options:
-h Displays command usage. If <op> is given, the specific
operator usage is displayed.
-e Displays more detailed error messages. Displays a stack
trace, if an exception occurs.
-t <file> The target file. Default value is 'target.dim'.
-f <format> Output file format, e.g. 'GeoTIFF', 'HDF5',
'BEAM-DIMAP'. If not specified, format will be derived
from the target filename extension, if any, otherwise the
default format is 'BEAM-DIMAP'. Ony used, if the graph
in<graph-file> does not specify its own 'Write'
operator.
-p <file> A (Java Properties)file containing processing parameters
in the form <name>=<value> or a XML file containing a
parameter DOM for the operator. Entries in this file are
overwritten by the -P<name>=<value> command-line option
(see below). The following variables are substituted in
the parameters file:
${system.}${operatorName}(given by the <op> argument)${graphFile}(given by the <graph-file> argument)${targetFile}(pull path given by the -t option)${targetDir}(derived from -t option)${targetName}(derived from -t option)${targetBaseName}(derived from -t option)${targetFormat}(given by the -f option)
-c <cache-size> Sets the tile cache size in bytes. Value can be suffixed
with 'K', 'M' and 'G'. Must be less than maximum
available heap space. If equal to or less than zero, tile
caching will be completely disabled. The default tile
cache size is '1,073,741,824M'.
-q <parallelism> Sets the maximum parallelism used for the computation,
i.e. the maximum number of parallel (native) threads.
The default parallelism is '8'.
-x Clears the internal tile cache after writing a complete
row of tiles to the target product file. This option may
be useful if you run into memory problems.
-S<source>=<file> Defines a source product. <source> is specified by the
operator or the graph. In an XML graph, all occurrences of
${} will be replaced with references to a source
product located at <file>.
-P<name>=<value> Defines a processing parameter, <name> is specific for the
used operator or graph. In an XML graph, all occurrences
of ${} will be replaced with <value>. Overwrites
parameter values specified by the '-p' option.
-D<name>=<value> Defines a system property for this invocation.
-v <dir> A directory containing any number of Velocity templates.
Each template generates a text output file along with the
target product. This feature has been added to support a
flexible generation of metadata files.
See http://velocity.apache.org/ and option -m.
-m <file> A (Java Properties)file containing (constant) metadata
in the form <name>=<value> or any XML file. Its primary
usage is to provide an additional context to be used
from within the Velocity templates. See option -v.
--diag Displays version and diagnostic information.
Operators:
Aatsr.SST Computes sea surface temperature (SST) from (A)ATSR products.
AATSR.Ungrid Ungrids (A)ATSR L1B products and extracts geolocation and pixel field of view data.
AdaptiveThresholding Detect ships using Constant False Alarm Rate detector.
AddElevation Creates a DEM band
AddLandCover Creates a land cover band
ALOS-Deskewing Deskewing ALOS product
Apply-Orbit-File Apply orbit file
Arc.SST Computes sea surface temperature (SST) from (A)ATSR and SLSTR products.
ArviOp Atmospherically Resistant Vegetation Index belongs to a family of indices with built-in atmospheric corrections.
Azimuth-Shift-Estimation-ESD Estimate azimuth offset for the whole image
AzimuthFilter Azimuth Filter
Back-Geocoding Bursts co-registration using orbit and DEM
BandMaths Create a product with one or more bands using mathematical expressions.
BandMerge Allows copying raster data from any number of source products to a specified 'master' product.
BandPassFilter Creates a basebanded SLC based on a subband of 1/3 the original bandwidth
BandsDifferenceOp No description available.
BandSelect Creates a new product with only selected bands
BandsExtractorOp Creates a new product out of the source product containing only the indexes bands given
Bi2Op The Brightness index represents the average of the brightness of a satellite image.
This index is sensitive to the brightness of soils which is highly correlated with the humidity and the presence of salts in surface
Binning Performs spatial and temporal aggregation of pixel values into cells ('bins') of a planetary grid
BiOp The Brightness index represents the average of the brightness of a satellite image.
Biophysical10mOp The 'Biophysical Processor' operator retrieves LAI from atmospherically corrected Sentinel-2 products
BiophysicalLandsat8Op The 'Biophysical Processor' operator retrieves LAI from atmospherically corrected Landsat8 products
BiophysicalOp The 'Biophysical Processor' operator retrieves LAI from atmospherically corrected Sentinel-2 products
c2rcc.landsat8 Performs atmospheric correction and IOP retrieval with uncertainties on Landsat-8 L1 data products.
c2rcc.meris Performs atmospheric correction and IOP retrieval with uncertainties on MERIS L1b data products.
c2rcc.meris4 Performs atmospheric correction and IOP retrieval with uncertainties on MERIS L1b data products from the 4th reprocessing.
c2rcc.modis Performs atmospheric correction and IOP retrieval on MODIS L1C_LAC data products.
c2rcc.msi Performs atmospheric correction and IOP retrieval with uncertainties on Sentinel-2 MSI L1C data products.
c2rcc.olci Performs atmospheric correction and IOP retrieval with uncertainties on SENTINEL-3 OLCI L1B data products.
c2rcc.seawifs Performs atmospheric correction and IOP retrieval on SeaWifs L1C data products.
c2rcc.viirs Performs atmospheric correction and IOP retrieval on Viirs L1C data products.
Calibration Calibration of products
Change-Detection Change Detection.
ChangeVectorAnalysisOp The 'Change Vector Analysis' between two dual bands at two differents dates.
CiOp Colour Index was developed to differentiate soils in the field.
In most cases the CI gives complementary information with the BI and the NDVI.
Used for diachronic analyses, they helpfor a better understanding of the evolution of soil surfaces.
CloudProb Applies a clear sky conservative cloud detection algorithm.
Coherence Estimate coherence from stack of coregistered images
Collocate Collocates two products based on their geo-codings.
Compactpol-Radar-Vegetation-Index Compact-pol Radar Vegetation Indices generation
Compute-Slope-Aspect Compute Slope and Aspect from DEM
Convert-Datatype Convert product data type
CoregistrationOp Coregisters two rasters, not considering their location
CP-Decomposition Perform Compact Polarimetric decomposition of a given product
CP-Simulation Simulation of Compact Pol data from Quad Pol data
CP-Stokes-Parameters Generates compact polarimetric Stokes child parameters
CreateStack Collocates two or more products based on their geo-codings.
Cross-Channel-SNR-Correction Compute general polarimetric parameters
Cross-Correlation Automatic Selection of Ground Control Points
CrossResampling Estimate Resampling Polynomial using SAR Image Geometry, and Resample Input Images
DarkObjectSubtraction Performs dark object subtraction for spectral bands insource product.
DeburstWSS Debursts an ASAR WSS product
DecisionTree Perform decision tree classification
DEM-Assisted-Coregistration Orbit and DEM based co-registration
Demodulate Demodulation and deramping of SLC data
Double-Difference-Interferogram Compute double difference interferogram
DviOp Difference Vegetation Index retrieves the Isovegetation lines parallel to soil line
EAP-Phase-Correction EAP Phase Correction
Ellipsoid-Correction-GG GG method for orthorectification
Ellipsoid-Correction-RD Ellipsoid correction with RD method and average scene height
EMClusterAnalysis Performs an expectation-maximization (EM) cluster analysis.
Enhanced-Spectral-Diversity Estimate constant range and azimuth offsets for a stack of images
Faraday-Rotation-Correction Perform Faraday-rotation correction for quad-pol product
Fill-DEM-Hole Fill holes in given DEM product file.
FlhMci Computes fluorescence line height (FLH) or maximum chlorophyll index (MCI).
Flip flips a product horizontal/vertical
ForestCoverChangeOp Creates forest change masks out of two source products
FUB.Water MERIS FUB-CSIRO Coastal Water Processor to retrieve case II water properties and atmospheric properties
FuClassification Colour classification based on the discrete Forel-Ule scale
GemiOp This retrieves the Global Environmental Monitoring Index (GEMI).
Generalized-Radar-Vegetation-Index Generalized Radar Vegetation Indices generation
GenericRegionMergingOp The 'Generic Region Merging' operator computes the distinct regions from a product
GLCM Extract Texture Features
GndviOp Green Normalized Difference Vegetation Index
GoldsteinPhaseFiltering Phase Filtering
GRD-Post Applies GRD post-processing
HorizontalVerticalMotion Computation of Horizontal/Vertical Motion Components
IEM-Hybrid-Inversion Performs IEM inversion using Hybrid approach
IEM-Multi-Angle-Inversion Performs IEM inversion using Multi-angle approach
IEM-Multi-Pol-Inversion Performs IEM inversion using Multi-polarization approach
Image-Filter Common Image Processing Filters
Import-Vector Imports a shape file into a product
IntegerInterferogram Create integer interferogram
Interferogram Compute interferograms from stack of coregistered S-1 images
IonosphericCorrection Estimation of Ionospheric Phase Screens
IpviOp Infrared Percentage Vegetation Index retrieves the Isovegetation lines converge at origin
IreciOp Inverted red-edge chlorophyll index
KDTree-KNN-Classifier KDTree KNN classifier
KMeansClusterAnalysis Performs a K-Means cluster analysis.
KNN-Classifier K-Nearest Neighbour classifier
Land-Cover-Mask Perform decision tree classification
Land-Sea-Mask Creates a bitmask defining land vs ocean.
LandWaterMask Operator creating a target product with a single band containing a land/water-mask.
LinearToFromdB Converts bands to/from dB
Maximum-Likelihood-Classifier Maximum Likelihood classifier
McariOp Modified Chlorophyll Absorption Ratio Index, developed to be responsive to chlorophyll variation
Mci.s2 Computes maximum chlorophyll index (MCI)for Sentinel-2 MSI.
Merge Allows merging of several source products by using specified 'master' as reference product.
Meris.Adapt.4To3 Provides the adaptation of MERIS L1b products from 4th to 3rd reprocessing.
Meris.CorrectRadiometry Performs radiometric corrections on MERIS L1b data products.
Meris.N1Patcher Copies an existing N1 file and replaces the data for the radiance bands
Minimum-Distance-Classifier Minimum Distance classifier
MndwiOp Modified Normalized Difference Water Index, allowing for the measurement of surface water extent
Mosaic Creates a mosaic out of a set of source products.
MphChl This operator computes maximum peak height of chlorophyll (MPH/CHL).
Msavi2Op This retrieves the second Modified Soil Adjusted Vegetation Index (MSAVI2).
MsaviOp This retrieves the Modified Soil Adjusted Vegetation Index (MSAVI).
MtciOp The Meris Terrestrial Chlorophyll Index, aims at estimating the Red Edge Position (REP).
This is the maximum slant point in the red and near-infrared region of the vegetal spectral reflectance.
It is useful for observing the chlorophyll contents, vegetation senescence, and stress for water and nutritional deficiencies, but it is less suitable for land classification
Multi-size Mosaic Creates a multi-size mosaic out of a set of source products.
Multi-Temporal-Speckle-Filter Speckle Reduction using Multitemporal Filtering
Multilook Averages the power across a number of lines in both the azimuth and range directions
MultiMasterInSAR Multi-master InSAR processing
MultiMasterStackGenerator Generates a set of master-slave pairs from a coregistered stack forusein SBAS processing
Multitemporal-Compositing Compute composite image from multi-temporal RTCs
Ndi45Op Normalized Difference Index using bands 4 and 5
NdpiOp The normalized differential pond index, combines the short-wave infrared band-I and the green band
NdtiOp Normalized difference turbidity index, allowing for the measurement of water turbidity
NdviOp The retrieves the Normalized Difference Vegetation Index (NDVI).
Ndwi2Op The Normalized Difference Water Index, allowing for the measurement of surface water extent
NdwiOp The Normalized Difference Water Index was developed for the extraction of water features
Object-Discrimination Remove false alarms from the detected objects.
Offset-Tracking Create velocity vectors from offset tracking
Oil-Spill-Clustering Remove small clusters from detected area.
Oil-Spill-Detection Detect oil spill.
OlciAnomalyFlagging Adds a flagging band indicating saturated pixels and altitude data overflows
OlciO2aHarmonisation Performs O2A band harmonisation on OLCI L1b product. Implements update v4 of R.Preusker, June 2020.
OlciSensorHarmonisation Performs sensor harmonisation on OLCI L1b product. Implements algorithm described in'OLCI A/B Tandem Phase Analysis'
Orientation-Angle-Correction Perform polarization orientation angle correction for given coherency matrix
Oversample Oversample the datset
OWTClassification Performs an optical water type classification based on atmospherically corrected reflectances.
PCA Performs a Principal Component Analysis.
PduStitching Stitches multiple SLSTR L1B product dissemination units(PDUs) of the same orbit to a single product.
PhaseToDisplacement Phase To Displacement Conversion along LOS
PhaseToElevation DEM Generation
PhaseToHeight Phase to Height conversion
PixEx Extracts pixels from given locations and source products.
Polarimetric-Classification Perform Polarimetric classification of a given product
Polarimetric-Decomposition Perform Polarimetric decomposition of a given product
Polarimetric-Matrices Generates covariance or coherency matrix for given product
Polarimetric-Parameters Compute general polarimetric parameters
Polarimetric-Speckle-Filter Polarimetric Speckle Reduction
PpeFiltering Performs Prompt Particle Event (PPE) filtering on OLCI L1B
Principle-Components Principle Component Analysis
ProductSet-Reader Adds a list of sources
PssraOp Pigment Specific Simple Ratio, chlorophyll index
PviOp Perpendicular Vegetation Index retrieves the Isovegetation lines parallel to soil line. Soil line has an arbitrary slope and passes through origin
Rad2Refl Provides conversion from radiances to reflectances or backwards.
Radar-Vegetation-Index Dual-pol Radar Vegetation Indices generation
Random-Forest-Classifier Random Forest based classifier
RangeFilter Range Filter
RayleighCorrection Performs radiometric corrections on OLCI, MERIS L1B and S2 MSI L1C data products.
Read Reads a data product from a given file location.
ReflectanceToRadianceOp The 'Reflectance To Radiance Processor' operator retrieves the radiance from reflectance using Sentinel-2 products
ReipOp The red edge inflection point index
Remodulate Remodulation and reramping of SLC data
RemoteExecutionOp The Remote Execution Processor executes on the remote machines a slave graph and then on the host machine it executes a master graph using the products created by the remote machines.
Remove-GRD-Border-Noise Mask no-value pixels for GRD product
RemoveAntennaPattern Remove Antenna Pattern
ReplaceMetadata Replace the metadata of the first product with that of the second
Reproject Reprojection of a source product to a target Coordinate Reference System.
Resample Resampling of a multi-size source product to a single-size target product.
RiOp The Redness Index was developed to identify soil colour variations.
RviOp Ratio Vegetation Index retrieves the Isovegetation lines converge at origin
S2repOp Sentinel-2 red-edge position index
S2Resampling Specific S2 resample algorithm
SAR-Mosaic Mosaics two or more products based on their geo-codings.
SAR-Simulation Rigorous SAR Simulation
SARSim-Terrain-Correction Orthorectification with SAR simulation
SaviOp This retrieves the Soil-Adjusted Vegetation Index (SAVI).
SetNoDataValue Set NoDataValueUsed flag and NoDataValue for all bands
SliceAssembly Merges Sentinel-1 slice products
SM-Dielectric-Modeling Performs SM inversion using dielectric model
SmacOp Applies the Simplified Method for Atmospheric Corrections of Envisat MERIS/(A)ATSR measurements.
SnaphuExport Export data and prepare conf filefor SNAPHU processing
SnaphuImport Ingest SNAPHU results into InSAR product.
Speckle-Divergence Detect urban area.
Speckle-Filter Speckle Reduction
SpectralAngleMapperOp Classifies a product using the spectral angle mapper algorithm
SRGR Converts Slant Range to Ground Range
Stack-Averaging Averaging multi-temporal images
Stack-Split Writes all bands to files.
StampsExport Export data for StaMPS processing
StatisticsOp Computes statistics for an arbitrary number of source products.
SubGraph Encapsulates a graph within a graph.
Subset Create a spatial and/or spectral subset of a data product.
Supervised-Wishart-Classification Perform supervised Wishart classification
TemporalPercentile Computes percentiles over a given time period.
Terrain-Correction RD method for orthorectification
Terrain-Flattening Terrain Flattening
Terrain-Mask Terrain Mask Generation
ThermalNoiseRemoval Removes thermal noise from products
Three-passDInSAR Differential Interferometry
TileCache Experimental Operator which provides a dedicated cache for its source product.
A guide on how this operator is used is provided at https://senbox.atlassian.net/wiki/x/VQCTLw.
TileWriter Writes a data product to a tiles.
TndviOp Transformed Normalized Difference Vegetation Index retrieves the Isovegetation lines parallel to soil line
ToolAdapterOp Tool Adapter Operator
TopoPhaseRemoval Compute and subtract TOPO phase
TOPSAR-Deburst Debursts a Sentinel-1 TOPSAR product
TOPSAR-DerampDemod Bursts co-registration using orbit and DEM
TOPSAR-Merge Merge subswaths of a Sentinel-1 TOPSAR product
TOPSAR-Split Creates a new product with only the selected subswath
TsaviOp This retrieves the Transformed Soil Adjusted Vegetation Index (TSAVI).
Undersample Undersample the datset
Unmix Performs a linear spectral unmixing.
Update-Geo-Reference Update Geo Reference
Warp Create Warp Function And Get Co-registrated Images
WdviOp Weighted Difference Vegetation Index retrieves the Isovegetation lines parallel to soil line. Soil line has an arbitrary slope and passes through origin
Wind-Field-Estimation Estimate wind speed and direction
Write Writes a data product to a file.
Usage: matlab [-h|-help]|[-n | -e][v=variant][-c licensefile][-display Xdisplay | -nodisplay][--noFigureWindows][-nosplash][-debug][-softwareopengl | -nosoftwareopengl][-desktop | -nodesktop | -nojvm][-batch MATLAB_command | -r MATLAB_command][-sd folder | -useStartupFolderPref][-logfile log][-singleCompThread][-jdb [port]][-Ddebugger [options]][-nouserjavapath]
-h|-help - Display arguments.
-n - Display final environment variables,
arguments, and other diagnostic
information. MATLAB is not run.
-e - Display ALL the environment variables and
their values to standard output. MATLAB
is not run. If the exit status is not
0 on returnthen the variables and values
may not be correct.
v=variant - Start the version of MATLAB found
in bin/glnxa64/variant instead of bin/glnxa64.
-c licensefile - Set location of the license file that MATLAB
should use. It can have the form port@host or
be a colon separated list of license files.
The LM_LICENSE_FILE and MLM_LICENSE_FILE
environment variables will be ignored.
-display Xdisplay - Send X commands to X server display, Xdisplay.
Linux only.
-nodisplay - Do not display any X commands. The MATLAB
desktop will not be started. However, unless
-nojvm is also provided the Java virtual machine
will be started.
-noFigureWindows - Disables the display of figure windows in MATLAB.
-nosplash - Do not display the splash screen during startup.
-softwareopengl - Force MATLAB to start with software OpenGL
libraries. Not available on macOS.
-nosoftwareopengl - Disable auto-selection of software OpenGL
when a graphics driver with known issues is detected.
Not available on macOS.
-debug - Provide debugging information especially for X
based problems. Linux only.
-desktop - Allow the MATLAB desktop to be started by a
process without a controlling terminal. This is
usually a required command line argument when
attempting to start MATLAB from a window manager
menu or desktop icon.
-nodesktop - Do not start the MATLAB desktop. Use the current
terminal for commands. The Java virtual machine
will be started.
-singleCompThread - Limit MATLAB to a single computational thread.
By default, MATLAB makes use of the multithreading
capabilities of the computer on which it is running.
-nojvm - Shut off all Java support by not starting the
Java virtual machine. In particular the MATLAB
desktop will not be started.
-jdb [port] - Enable remote Java debugging on port (default 4444)
-batch MATLAB_command - Start MATLAB and execute the MATLAB command(s) with no desktop
and certain interactive capabilities disabled. Terminates
upon successful completion of the command and returns exit
code 0. Upon failure, MATLAB terminates with a non-zero exit.
Cannot be combined with -r.
-r MATLAB_command - Start MATLAB and execute the MATLAB_command.
Cannot be combined with -batch.
-sd folder - Set the MATLAB startup folder to folder, specified as a string.
Cannot be combined with -useStartupFolderPref.
-useStartupFolderPref - Set the MATLAB startup folder to the value
specified by the Initial working folder option
in the General Preferences panel.
Cannot be combined with -sd.
-logfile log - Make a copy of any output to the command window
infile log. This includes all crash reports.
-Ddebugger [options] - Start debugger to debug MATLAB.
-nouserjavapath - Ignore custom javaclasspath.txt and javalibrarypath.txt files.
matlab -display Xdisplay
MATLAB is selecting SOFTWARE OPENGL rendering.
< M A T L A B (R)>
Copyright 1984-2021 The MathWorks, Inc.
R2021a (9.10.0.1602886)64-bit (glnxa64)
February 17, 2021
To get started, type doc.
For product information, visit www.mathworks.com.
>>
3.3 StaMPS
StaMPS is a software package that allows to extract ground displacements from time series of synthetic aperture radar (SAR) acquisitions. The package incorporates persistent scatterer and small baseline methods plus an option to combine both approaches. It is compatible with the TRAIN software and therefore allows to incorporate various tropospheric correction methods in the processing workflow.
StaMPS(Stanford Method for Persistent Scatterers)软件可以从SAR时序数据(ISCE, SNAP, GAMMA, and ROI PAC and DORIS等软件通过对SLC数据预处理可得到)中提取地面位移。
The TOPSAR Split operator provides a convenient way to split each subswath with selected bursts into a separate product. This operator is the first processing step in the TOPS InSAR processing chain.
The user may select the desired subswath with desired bursts and polarisations.
4.1.2. Apply Orbit File
The orbit state vectors provided in the metadata of a SAR product are generally not accurate and can be refined with the precise orbit files which are available days-to-weeks after the generation of the product.
The orbit file provides accurate satellite position and velocity information. Based on this information, the orbit state vectors in the abstract metadata of the product are updated.
4.1.3. InSAR Stack Overview
This function gives a general information about the interferometric stack. The information about the acquisition date, sensor, mode, as well as information about perpendicular and temporal baselines are being listed. Also an estimate for the modeled (expected) coherence is being computed, and used in selection of the optimal reference image for the InSAR stack.
The reference image is selected such that the dispersion of the perpendicular baseline is as low as possible. The reference image is selected maximizing the (expected) stack coherence of the interferometric stack. The “optimal” reference implies improved visual interpretation of the interferograms and aids quality assessment.
4.1.4. Sentinel-1 Back Geocoding
This operator co-registers two S-1 SLC split products (reference and secondary) of the same sub-swath using the orbits of the two products and a Digital Elevation Model (DEM).
In resampling the secondary images into reference frame, deramp and demodulation are performed first to the secondary image, then the truncated-sinc interpolation is performed. Finally, the reramp and remodulation are applied to the interpolated secondary image.
4.1.5. Sentinel-1 TOPSAR Deburst and Merge
For the TOPSAR IW and EW SLC products, each product consists of one image per swath per polarization. IW products have 3 swaths and EW have 5 swaths. Each sub-swath image consists of a series of bursts, where each burst was processed as a separate SLC image. The individually focused complex burst images are included, in azimuth-time order, into a single subswath image, with black-fill demarcation in between, similar to the ENVISAT ASAR Wide ScanSAR SLC products.
For IW, a focused burst has a duration of 2.75 sec and a burst overlap of ~50-100 samples. For EW, a focused burst has a duration of 3.19 sec. Overlap increases in range within a sub- swath.
Images for all bursts in all sub-swaths of an IW SLC product are re-sampled to a common pixel spacing grid in range and azimuth. Burst synchronisation is ensured for both IW and EW products.
Unlike ASAR WSS which contains large overlap between beams, for S-1 TOPSAR, the imaged ground area of adjacent bursts will only marginally overlap in azimuth just enough to provide contiguous coverage of the ground. This is due to the one natural azimuth look inherent in the data.
For GRD products, the bursts are concatenated and sub-swaths are merged to form one image. Bursts overlap minimally in azimuth and sub-swaths overlap minimally in range. Bursts for all beams have been resampled to a common grid during azimuth post-processing.
In the range direction, for each line in all sub-swaths with the same time tag, merge adjacent sub-swaths. For the overlapping region in range, merging is done midway between subswaths.
In the azimuth direction, bursts are merged according to their zero Doppler time. Note that the black-fill demarcation is not distinctly zero at the end or start of the burst. Due to resampling, the data fades into zero and out. The merge time is determined by the average of the last line of the first burst and the first line of the next burst. For each range cell, the merging time is quantised to the nearest output azimuth cell to eliminate any fading to zero data.
4.1.6. Interferogram formation (InSAR operator)
This operator computes (complex) interferogram, with or without subtraction of the flat-earth (reference) phase. The reference phase is subtracted using a 2d-polynomial that is also estimated in this operator.
If the orbits for interferometric pair are known, the flat-earth phase is estimated using the orbital and metadata information and subtracted from the complex interferogram. The flat-earth phase is the phase present in the interferometric signal due to the curvature of the reference surface. The geometric reference system of the reference surface is defined by the reference system of satellite orbits (for now only WGS84 supported, which the reference system used by all space-borne SAR systems).
The flat-earth phase is computed in a number of points distributed over the total image, after which a 2d-polynomial is estimated (using least squares) fitting these ‘observations’, (e.g. plane can be fitted by setting the degree to 1.)
A polynomial of degree 5 normally is sufficient to model the reference phase for a full SAR scene (approx 100x100km). While, a lower degree might be selected for smaller images, and higher degree for ‘long-swath’ scenes. Note that the higher order terms of the flat-earth polynomial are usually small, because the polynomial describes a smooth, long wave body (ellipsoid). To recommended polynomial degree, that should ensure the smooth surface for most image sizes and areas of the world is 5th degree.
In order to reduce the noise, as the post-processing step, you can perform multilooking (with Multilook Operator). Multilooking has to be performed separately on ‘virtual’ bands phase or intensity. In future releases complex Multilook operator will be released. Note that in case of ESA’s ERS and Envisat sensors, the factor 5:1 (azimuth:range) or similar ratio between the factors is chosen to obtain approximately square pixels (20x20 m^2 for factors 5 and 1). Of course the resolution decreases if multilooking is applied
4.1.7. StaMPS Export
Use the StaMPS Export to produce data that can be used within the StaMPS applicaiton for Persistent Scattering Interferometry (PSI).
0.4 = amplitude dispersion (0.4-0.42 are reasonable values)
3 = number of patches in range (default 1)
2 = number of patches in azimuth, (default 1)
50 = overlapping pixels between patches in range (default 50)
200 = overlapping pixels between patches in azimuth (default 200)
The number of patches you choose will depend on the size of your area and the memory on your
computer. Generally, patches containing < 5 million SLC pixels are OK.
java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getImportantForAccessibility()' on a null object reference
出现以上异常.然后就在baidu上
cmd命令打jar是如下实现:
在运行里输入cmd,利用cmd命令进入到本地的工作盘符。(如我的是D盘下的文件有此路径 D:\workspace\prpall\WEB-INF\classes)
现在是想把D:\workspace\prpall\WEB-INF\classes路径下所有的文件打包成prpall.jar。然后继续如下操作:
cd D: 回车
cd workspace/prpal
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml&q
Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area.
public class Solution {
public int maximalRectangle(char[][] matrix)
随着RESTful Web Service的流行,测试对外的Service是否满足期望也变的必要的。从Spring 3.2开始Spring了Spring Web测试框架,如果版本低于3.2,请使用spring-test-mvc项目(合并到spring3.2中了)。
Spring MVC测试框架提供了对服务器端和客户端(基于RestTemplate的客户端)提供了支持。
&nbs
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
/*you'll also need to set UIViewControllerBasedStatusBarAppearance to NO in the plist file if you use this method
英文资料:
Thread Dump and Concurrency Locks
Thread dumps are very useful for diagnosing synchronization related problems such as deadlocks on object monitors. Ctrl-\ on Solaris/Linux or Ctrl-B