diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5079f558..49449f59 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [PEP 440](https://www.python.org/dev/peps/pep-0440/)
 and uses [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [6.1.0]
+
+### Added
+- A `--phase-filter-paameter` option has been added to the `__main__` (HyP3) and `ifm_sentinel.py` entry points to specify the adaptive phase filter parameter used when processing InSAR products. The provided value is ultimately passed to the `alpha` argument of the `adf` GAMMA function, which uses the algorithm with a constant exponent as described in https://doi.org/10.1029/1998GL900033.
+
 ## [6.0.1]
 
 ### Fixed
diff --git a/hyp3_gamma/__main__.py b/hyp3_gamma/__main__.py
index 35d11884..0f1710fc 100644
--- a/hyp3_gamma/__main__.py
+++ b/hyp3_gamma/__main__.py
@@ -112,6 +112,13 @@ def rtc():
             upload_file_to_s3(product_file, args.bucket, args.bucket_prefix)
 
 
+def phase_filter_valid_range(x: str) -> float:
+    x = float(x)
+    if 0.0 < x <= 1.0:
+        return x
+    raise ValueError(f'{x} not in range (0.0, 1.0]')
+
+
 def insar():
     parser = ArgumentParser()
     parser.add_argument('--username')
@@ -126,6 +133,7 @@ def insar():
     parser.add_argument('--include-inc-map', type=string_is_true, default=False)
     parser.add_argument('--apply-water-mask', type=string_is_true, default=False)
     parser.add_argument('--looks', choices=['20x4', '10x2'], default='20x4')
+    parser.add_argument('--phase-filter-parameter', type=phase_filter_valid_range, default=0.6)
     parser.add_argument('granules', type=str.split, nargs='+')
     args = parser.parse_args()
 
@@ -160,6 +168,7 @@ def insar():
         include_wrapped_phase=args.include_wrapped_phase,
         include_inc_map=args.include_inc_map,
         apply_water_mask=args.apply_water_mask,
+        phase_filter_parameter=args.phase_filter_parameter
     )
 
     output_zip = make_archive(base_name=product_name, format='zip', base_dir=product_name)
diff --git a/hyp3_gamma/insar/ifm_sentinel.py b/hyp3_gamma/insar/ifm_sentinel.py
index 6c5b3a1e..7ac025e5 100755
--- a/hyp3_gamma/insar/ifm_sentinel.py
+++ b/hyp3_gamma/insar/ifm_sentinel.py
@@ -233,7 +233,8 @@ def move_output_files(output, reference, prod_dir, long_output, include_displace
                   "{}_unw_phase".format(os.path.join(prod_dir, long_output)), use_nn=True)
 
 
-def make_parameter_file(mydir, parameter_file_name, alooks, rlooks, dem_source, coords, ref_point_info):
+def make_parameter_file(mydir, parameter_file_name, alooks, rlooks, dem_source, coords,
+                        ref_point_info, phase_filter_parameter):
     res = 20 * int(alooks)
 
     reference_date = mydir[:15]
@@ -316,7 +317,7 @@ def make_parameter_file(mydir, parameter_file_name, alooks, rlooks, dem_source,
         f.write('Range looks: %s\n' % rlooks)
         f.write('Azimuth looks: %s\n' % alooks)
         f.write('INSAR phase filter:  adf\n')
-        f.write('Phase filter parameter: 0.6\n')
+        f.write('Phase filter parameter: %s\n' % phase_filter_parameter)
         f.write('Resolution of output (m): %s\n' % res)
         f.write('Range bandpass filter: no\n')
         f.write('Azimuth bandpass filter: no\n')
@@ -336,7 +337,7 @@ def make_parameter_file(mydir, parameter_file_name, alooks, rlooks, dem_source,
 
 def insar_sentinel_gamma(reference_file, secondary_file, rlooks=20, alooks=4, include_look_vectors=False,
                          include_displacement_maps=False, include_wrapped_phase=False, include_inc_map=False,
-                         include_dem=False, apply_water_mask=False):
+                         include_dem=False, apply_water_mask=False, phase_filter_parameter=0.6):
     log.info("\n\nSentinel-1 differential interferogram creation program\n")
 
     wrk = os.getcwd()
@@ -419,7 +420,7 @@ def insar_sentinel_gamma(reference_file, secondary_file, rlooks=20, alooks=4, in
     log.info("Starting phase unwrapping and geocoding")
 
     coords, ref_point_info = unwrapping_geocoding(reference, secondary, step="man", rlooks=rlooks, alooks=alooks,
-                                                  apply_water_mask=apply_water_mask)
+                                                  alpha=phase_filter_parameter, apply_water_mask=apply_water_mask)
 
     # Generate metadata
     log.info("Collecting metadata and output files")
@@ -454,7 +455,7 @@ def insar_sentinel_gamma(reference_file, secondary_file, rlooks=20, alooks=4, in
     execute(f"base_init {reference}.slc.par {secondary}.slc.par - - base > baseline.log", uselogging=True)
 
     make_parameter_file(igramName, f'{product_name}/{product_name}.txt', alooks, rlooks,
-                        dem_source, coords, ref_point_info)
+                        dem_source, coords, ref_point_info, phase_filter_parameter)
 
     log.info("Done!!!")
     return product_name
@@ -476,6 +477,8 @@ def main():
     parser.add_argument("-s", action="store_true", help="Create both line of sight and vertical displacement files")
     parser.add_argument("-w", action="store_true", help="Create wrapped phase file")
     parser.add_argument("-m", action="store_true", help="Apply water mask")
+    parser.add_argument("-p", "--phase-filter-parameter", default=0.6, help="Adaptive phase filter parameter")
+
     args = parser.parse_args()
 
     logging.basicConfig(format='%(asctime)s - %(levelname)s - %(message)s',
@@ -484,7 +487,8 @@ def main():
     insar_sentinel_gamma(args.reference, args.secondary, rlooks=args.rlooks, alooks=args.alooks,
                          include_look_vectors=args.l, include_displacement_maps=args.s,
                          include_wrapped_phase=args.w, include_inc_map=args.i,
-                         include_dem=args.d, apply_water_mask=args.m)
+                         include_dem=args.d, apply_water_mask=args.m,
+                         phase_filter_parameter=args.phase_filter_parameter)
 
 
 if __name__ == "__main__":