PSINANG

Description

PSINANG creates a single-channel PCIDSK file with a two-dimensional image of incident angle values. The incident angle map image can be created only for existing polarimetric SAR (POLSAR) data sets with known incident angle information. The incident angle image is created by replicating the one-dimensional incident angle vector for all image lines. If the input image has no incident angle information, the program exits with an error. The new file has the same number of pixels and lines as the input data set, and angle values can be written in degrees or radians.

Parameters

Name	Type	Caption	Length	Value range
FILI*	String	Input complex or detected SAR image	1 - 192
FILO*	String	Output incident angle map	1 - 192
ANGLETYP	String	Angle measurement units	0 - 6	degree | radian Default: degree
MONITOR	String	Monitor mode	0 - 3	ON, OFF Default: ON

* Required parameter

Parameter descriptions

FILI

Specifies the name of the PCIDSK format or GDB-supported file that contains the input matrix data to filter.

The input data must be a data set that has already been imported into the PCIDSK (.pix) format by SARINGEST or it may be the key file name of any GDB-supported POLSAR data set in its distribution format. For more information and a complete list of supported POLSAR sensors and data products, see the SARINGEST Help.

FILO

Specifies the name of the PCIDSK file that is created. The file must not already exist. The output file has the same number of pixels and lines as the input file, and one channel with floating point pixel values.

ANGLETYP

Specifies units of the angle values in the output file, in degrees or radians.

MONITOR

The program progress can be monitored by printing the percentage of processing completed. A system parameter, MONITOR, controls this activity.

Available options are:

• ON: Turns the monitor ON (default)
• OFF: Turns the monitor OFF (recommended if running in batch or background mode)

Details

Most of the POLSAR data sets contain incident angle information. For these data sets, PSINANG creates a single-channel PCIDSK file with an incidence angle map, which provides an incident angle value at every pixel in the image. The incident angle information in the input file is in the form of a vector of values with an incident angle for every pixel column (along the SAR range lines). For some POLSAR data, a decimated vector is provided. In such cases, PSINANG interpolates the values to every pixel position in the range direction before creating the output incident angle map.

If the input data set contains multiple files, FILI (Input) must specify the key file name specific to a given data product. For more information and a complete list of key file names for all supported POLSAR data products, refer to the SARINGEST documentation.

If the input data set has no incident angle information, PSINANG exits with an error. This is the case for CV-580 data and for georeferenced and geocorrected simulated RADARSAT-2 data.

The output PCIDSK file has the same number of lines and pixels as FILI and contains a single channel with floating point pixel values. Each pixel contains an incident angle value, in degrees or radians, depending on the value of the ANGLETYP (Angle Units) parameter.

The output incident angle map is created by replicating the original incident angle vector for every image line. This means that the output map has angle values that vary in the pixel direction (along image lines), but are constant in the line direction (along pixel columns).

Examples

Create an incident angle map for a simulated RADARSAT-2 product with angle values in radians.

EASI>FILI	=	"product.xml" 
EASI>FILO	=	"r2_angle.pix"
EASI>ANGLETYP	=	"radian"

EASI>run PSINANG
            

In the following example, create an incident angle map for an already imported ASAR image with angle values in degrees.

EASI>FILI	=	"asa_aps.pix"
EASI>FILO	=	"asa_angle.pix"
EASI>ANGLETYP	=

EASI>run PSINANG
            

Acknowledgements

PCI Geomatics gratefully acknowledges the financial support provided by the Canadian Space Agency through the Earth Observation Application Development Program (EOADP), contract number 9F028-034946. This support was essential to the development of the SAR Polarimetry Workstation.