extract rank and prf (#31)

* extract rank and prf

* less call

* clean whitespaces

Author: hfattahi

src/s1reader/s1_burst_slc.py

@@ -195,7 +195,8 @@ class Sentinel1BurstSlc:
     # window parameters
     range_window_type: str
     range_window_coefficient: float
-
+    rank: int # The number of PRI between transmitted pulse and return echo.
+    prf_raw_data: float  # Pulse repetition frequency (PRF) of the raw data [Hz]
 
     def as_isce3_radargrid(self):
         '''Init and return isce3.product.RadarGridParameters.

src/s1reader/s1_reader.py

@@ -294,6 +294,10 @@ def burst_from_xml(annotation_path: str, orbit_path: str, tiff_path: str,
         slant_range_time = float(image_info_element.find('slantRangeTime').text)
         ascending_node_time = as_datetime(image_info_element.find('ascendingNodeTime').text)
 
+        downlink_element =  tree.find('generalAnnotation/downlinkInformationList/downlinkInformation')
+        prf_raw_data = float(downlink_element.find('prf').text)
+        rank = int(downlink_element.find('downlinkValues/rank').text)
+
         n_lines = int(tree.find('swathTiming/linesPerBurst').text)
         n_samples = int(tree.find('swathTiming/samplesPerBurst').text)
 
@@ -384,7 +388,8 @@ def burst_from_xml(annotation_path: str, orbit_path: str, tiff_path: str,
                                       boundary_pts[i], orbit, orbit_direction,
                                       tiff_path, i, first_valid_sample,
                                       last_sample, first_valid_line, last_line,
-                                      range_window_type, range_window_coeff)
+                                      range_window_type, range_window_coeff,
+                                      rank, prf_raw_data)
 
     return bursts