PAZ

Long name PAZ
Short name PAZ
Sensor type Synthetic-aperture radar (SAR)
Platform PAZ
Frequency 9.65 GHz
Band (wavelength) X (3.1 cm)
Polarization VV, HH, HV, VH
Key file name (use to open data set) *.xml
Supported file name extensions *.xml, *.cos, *.tif, *.png, *.txt
Data distributor Hisdesat (formerly SEOSAR)
Sections

Data product name and description
Distribution disk files
Returned data for supported format
References

Data product name and description

PAZ has the following acquisition modes:
  • High-Resolution Spotlight
  • Spotlight
  • StripMap
  • ScanSAR
Note: The information provided herein is based on the data distributor's documentation cited under References.
Mode Swath width (km) Resolution (range x azimuth, m)* Polarization Description/notes
High-Resolution Spotlight

Single pol. [HR-S]
Dual pol. [HR-D]

10



≈ 0.6 x 1.05
≈ 1.17 x 2.16



HH or VV
HH+VV or HH+HV or VV+VH

 
Spotlight

Single pol. [SL-S]
Dual pol. [SL-D]

10



≈ 1.18 x 1.46
≈ 1.17 x 3.10



HH or VV
HH+VV or HH+HV or VV+VH

 
StripMap

Single pol. [SM-S]
Dual pol. [SM-D]



30
15



≈ 1.1 x 3.01
≈ 1.1 x 6.04



HH or VV
HH+VV or HH+HV or VV+VH

 
ScanSAR [SC] 100 ≤ 20 x 20 HH or VV  

* Resolution is always single-look complex (SLC) unless noted otherwise.

PAZ data sets are available in various processing levels, as described in the following table.

Processing level Acquisition mode Description/notes

1B
Single-look, slant range, complex (SSC)

[HR], [SL], [SM] SSC is a single-look product of the focused radar signal. The pixels are spaced equidistant in azimuth according to the pulse-repetition interval (PRI=1/PRF) and in slant range according to the range-sampling frequency. The data is represented as complex numbers containing amplitude and phase information. Each image pixel is processed to zero Doppler coordinates in range direction; that is, perpendicular to the flight track.

1B
Multi-look, ground range, detected (MGD)

[HR], [SL], [SM], [SC] MGD is a detected multilook product with reduced speckle and resolution cells that are approximately square. The image coordinates are oriented along the direction of flight and along ground range. The pixel spacing is equidistant in azimuth and in ground range. With the slant-to-ground-range projection the WGS84 ellipsoid and an average, constant-terrain-height value are used.

1B
Geocoded ellipsoid corrected (GEC)

[HR], [SL], [SM], [SC] GEC is a multilook, detected product, which is resampled and projected to the WGS84 reference ellipsoid assuming one average height. The image is represented in map geometry with ellipsoidal corrections only, and no terrain correction is performed. Available grid formats are Universal Transverse Mercator (UTM) and universal polar stereographic (UPS). Because the ellipsoid correction does not use height information from a digital elevation model (DEM) for geometric correction, the pixel-location accuracy varies according to local terrain. With other types of relief, the terrain-induced, SAR-specific distortions are not corrected and significant location shifts can appear, particularly with strong relief, steep incidence angles, or both.
1B Enhanced ellipsoid corrected (EEC) [HR], [SL], [SM], [SC] EEC is a multi-look, detected product, which is resampled and projected to the WGS84 reference ellipsoid. Image distortions caused by varying terrain height are corrected using an external DEM. The image is represented in map geometry with terrain correction. The available map projections are UTM or UPS.

Distribution disk files

A PAZ data set is organized in a specific folder structure on disk. GDB uses this folder structure and the file names to identify the data product type.

PAZ complex data (SSC) is distributed in COSAR format. Detected data (MGD, GEC, EEC) is distributed in GeoTIFF format.

File name convention

The file name convention of PAZ data is described as follows, based on a sample file name of PAZ1_SAR__AAA_BBBB_CC_D_EEE_xxxxxxxxTxxxxxx_yyyyyyyyTyyyyyy.xml.

File name segment Description
PAZ1 Mission, satellite ID
SAR Sensor
AAA Product variant (SSC, MGD, GEC, EEC)
BBBB Resolution variant (SE__, RE__)
CC Image mode (SM, SC, SL, HS)
D Polarization mode (S, D, T, Q)
EEE Antenna-receive configuration: single-receive (SRA) or dual-receive (DRA)
xxxxxxxxTxxxxxx

UTC start time.
Format: YYYYMMDDThhmmss

xxxxxxxxTxxxxxx

UTC stop time.
Format: YYYYMMDDThhmmss

Warning: Data sets for this sensor are organized in a specific folder structure on disk. GDB uses this structure and the file names to identify the data product type. Do not alter the folder structure or any file names prior to data ingestion to ensure the image data and auxiliary information are imported correctly.

You can open a PAZ data set by selecting the *.xml file.

When opening a PAZ data set, the files read by GDB are as described in the following table.

Table 1. COSAR
File name Format Required Contents/details
*.cos Binary Yes

DLR-defined COSAR binary format. Contains image data. One file per polarization.
(IMAGEDATA folder)

*.xml Extensible Markup Language Yes Key file name. Main product annotation file.
georef.xml Extensible Markup Language Yes

Georeference file.
(ANNOTATION folder)

Table 2. GeoTIFF
File name Format Required Contents/details
*.tif GeoTIFF Yes

Contains image data. One GeoTIFF file per polarization.
(IMAGEDATA folder)

*.xml Extensible Markup Language Yes Key file name. Main product annotation file.
georef.xml Extensible Markup Language Yes

Georeference file.
(ANNOTATION folder)

Returned data for supported format

PAZ data can be opened directly in its raw vendor format or imported into a PCIDSK (*.pix) file using the key file name (*.xml). For optimal processing, use the PCIDSK format.

The following table describes the data structure after it is opened by GDB.

Data product Data returned Details
SSC (single)

1 x [C16S] raster channel (uncalibrated)
- or -
1 x [C32R] raster channel (calibrated)

1 x [GCP] ground control points
1 x [TEX] main product annotation
1 x [ORB] orbit segment
1 x [BIN] rational function model from state vectors
1 x [ARR] incidence angle array

Data can be calibrated in sigma, beta, or gamma nought.
SSC (dual)

2 x [C16S] raster channels (uncalibrated)
- or -
2 x [C32R] raster channel (calibrated)

1 x [GCP] ground control points
1 x [TEX] main product annotation
1 x [ORB] orbit segment
1 x [BIN] rational function model from state vectors
1 x [ARR] incidence angle array

Data can be calibrated in sigma, beta, or gamma nought.
MGD (single)

1 x [16U] raster channel (uncalibrated)
- or -
1 x [32R] raster channel (calibrated)

1 x [TEX] main product annotation
1 x [ORB] orbit segment
1 x [BIN] rational function model from state vectors
1 x [ARR] incidence angle array

Data can be calibrated in sigma, beta, or gamma nought.
MGD (dual)

2 x [16U] raster channels (uncalibrated)
- or -
2 x [32R] raster channels (calibrated)

1 x [TEX] main product annotation
1 x [ORB] orbit segment
1 x [BIN] rational function model from state vectors
1 x [ARR] incidence angle array

Data can be calibrated in sigma, beta, or gamma nought.

GEC (single)
EEC (single)

1 x [16U] raster channel (uncalibrated)
- or -
1 x [32R] raster channel (calibrated)

1 x [TEX] main product annotation

Data can be calibrated in beta nought.

GEC (dual)
EEC (dual)

2 x [16U] raster channels (uncalibrated)
- or -
2 x [32R] raster channels (calibrated)

1 x [TEX] main product annotation

Data can be calibrated in beta nought.

References

PAZ SAR Processor. SAR Level 1b product format specification for PAZ SAR Processor. MF - Remote Sensing Technology Institute. DLR. Doc PZ-DLR-ID-303. Issue 1.0. Date 01.10.2010. 309 pages.

PAZ Mission Scientific Exploitation. Announcement of Opportunity: Launch of PAZ Science Phase. REF: PAZ/INT/CALVAL/AO/001. Issue 1. Date: 15/01/2019. Instituto Nacional de Técnica Aeroespacial (INTA). Departamento de Programas Espaciales y Ciencias del Espacio, ESPAÑA. 19 pages.

EO Portal Directory. PAZ SAR satellite mission of Spain. ESA 200-2019.
For more information, visit: eoportal.org

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