v1.8.1-beta2 - KA9Q Channel Filter, RS41/DFM Estimator BW Tweaks

README.md

@@ -40,6 +40,8 @@ Improvements from the upstream RS codebase will be merged into this codebase whe
 Please consider joining the Google Group to receive updates on new software features:
 https://groups.google.com/forum/#!forum/radiosonde_auto_rx
 
+We also have a channel in the SondeHub Discord server: https://sondehub.org/go/discord
+
 ## Presentations
 * Linux.conf.au 2019 - https://www.youtube.com/watch?v=YBy-bXEWZeM
 * UKHAS Conference 2019 - [Presented via Skype](https://youtu.be/azDJmMywBgw?t=643) which had some audio issues at the start. Slides [here](https://rfhead.net/sondes/auto_rx_presentation_UKHAS2019.pdf).

auto_rx/autorx/__init__.py

@@ -12,7 +12,7 @@
 # MINOR - New sonde type support, other fairly big changes that may result in telemetry or config file incompatability issus.
 # PATCH - Small changes, or minor feature additions.
 
-__version__ = "1.8.1-beta1"
+__version__ = "1.8.1-beta2"
 
 # Global Variables
 

auto_rx/autorx/decode.py

@@ -829,9 +829,10 @@ def generate_decoder_command_experimental(self):
             _baud_rate = 4800
             _sample_rate = 48000 # 10x Oversampling
 
-            # Limit FSK estimator window to roughly +/- 10 kHz
-            _lower = -10000
-            _upper = 10000
+            # Limit FSK estimator window to roughly +/- 5 kHz
+            _lower = -5000
+            _upper = 5000
+
 
             demod_cmd = get_sdr_iq_cmd(
                 sdr_type = self.sdr_type,
@@ -844,14 +845,17 @@ def generate_decoder_command_experimental(self):
                 ppm = self.ppm,
                 gain = self.gain,
                 bias = self.bias,
-                dc_block = True
+                dc_block = True,
+                channel_filter = 5000 # +/- 5 kHz channel filter.
             )
 
             # Add in tee command to save IQ to disk if debugging is enabled.
             if self.save_decode_iq:
                 demod_cmd += f" tee {self.save_decode_iq_path} |"
 
-            demod_cmd += "./fsk_demod --cs16 -b %d -u %d -s --stats=%d 2 %d %d - -" % (
+            # Use a 4800 Hz mask estimator to better avoid adjacent sonde issues.
+            # Also seems to give a small performance bump.
+            demod_cmd += "./fsk_demod --cs16 -b %d -u %d -s --mask 4800 --stats=%d 2 %d %d - -" % (
                 _lower,
                 _upper,
                 _stats_rate,
@@ -949,15 +953,16 @@ def generate_decoder_command_experimental(self):
             _baud_rate = 2500
             _sample_rate = 50000 # 10x Oversampling
 
-            # Limit FSK estimator window to roughly +/- 10 kHz
-            _lower = -10000
-            _upper = 10000
+            # Limit FSK estimator window to roughly +/- 5 kHz
+            _lower = -5000
+            _upper = 5000
 
-            if (abs(403200000 - self.sonde_freq) < 20000) and (self.sdr_type == "RTLSDR"):
-                # Narrow up the frequency estimator window if we are close to
-                # the 403.2 MHz RTLSDR Spur.
-                _lower = -8000
-                _upper = 8000
+            # Un-necessary.
+            # if (abs(403200000 - self.sonde_freq) < 20000) and (self.sdr_type == "RTLSDR"):
+            #     # Narrow up the frequency estimator window if we are close to
+            #     # the 403.2 MHz RTLSDR Spur.
+            #     _lower = -8000
+            #     _upper = 8000
 
             demod_cmd = get_sdr_iq_cmd(
                 sdr_type = self.sdr_type,
@@ -970,14 +975,16 @@ def generate_decoder_command_experimental(self):
                 ppm = self.ppm,
                 gain = self.gain,
                 bias = self.bias,
-                dc_block = True
+                dc_block = True,
+                channel_filter = 5000
             )
 
             # Add in tee command to save IQ to disk if debugging is enabled.
             if self.save_decode_iq:
                 demod_cmd += f" tee {self.save_decode_iq_path} |"
 
             # NOTE - Using inverted soft decision outputs, so DFM type detection works correctly.
+            # No mask estimator - DFMs seem to decode better without it!
             demod_cmd += "./fsk_demod --cs16 -b %d -u %d -s -i --stats=%d 2 %d %d - -" % (
                 _lower,
                 _upper,

auto_rx/autorx/ka9q.py

@@ -17,20 +17,29 @@ def ka9q_setup_channel(
     sdr_hostname,
     frequency,
     sample_rate,
-    scan
+    scan,
+    channel_filter = None
 ):
     if scan:
         ssrc="04"
     else:
         ssrc="01"
 
     # tune --samprate 48000 --frequency 404m09 --mode iq --ssrc 404090000 --radio sonde.local
+
+    if channel_filter:
+        _low = int(channel_filter * -1.0)
+        _high = int(channel_filter)
+    else:
+        _low = int(int(sample_rate) / (-2.4))
+        _high = int(int(sample_rate) / 2.4)
+
     _cmd = (
         f"{timeout_cmd()} 5 " # Add a timeout, because connections to non-existing servers block for ages
         f"tune "
         f"--samprate {int(sample_rate)} "
         f"--mode iq "
-        f"--low {int(int(sample_rate) / (-2.4))} --high {int(int(sample_rate) / 2.4)} "
+        f"--low {_low} --high {_high} "
         f"--frequency {int(frequency)} "
         f"--ssrc {round(frequency / 1000)}{ssrc} "
         f"--radio {sdr_hostname}"
@@ -120,15 +129,16 @@ def ka9q_get_iq_cmd(
         sdr_hostname,
         frequency,
         sample_rate,
-        scan
+        scan,
+        channel_filter = None
 ):
     if scan:
         ssrc="04"
     else:
         ssrc="01"
 
     # We need to setup a channel before we can use it!
-    _setup_success = ka9q_setup_channel(sdr_hostname, frequency, sample_rate, scan)
+    _setup_success = ka9q_setup_channel(sdr_hostname, frequency, sample_rate, scan, channel_filter)
 
     if not _setup_success:
         logging.critical(f"KA9Q ({sdr_hostname}) - Could not setup rx channel! Decoder will likely timeout.")

auto_rx/autorx/sdr_wrappers.py

@@ -281,7 +281,8 @@ def get_sdr_iq_cmd(
     sdr_hostname = "",
     sdr_port = 5555,
     ss_iq_path = "./ss_iq",
-    scan = False
+    scan = False,
+    channel_filter = None
 ):
     """
     Get a command-line argument to get IQ (signed 16-bit) from a SDR
@@ -303,7 +304,8 @@ def get_sdr_iq_cmd(
     Arguments for KA9Q SDR Server / SpyServer:
     sdr_hostname (str): Hostname of KA9Q Server
     sdr_port (int): Port number of KA9Q Server
-    scan (bool): Create unique SSRC for scan attempts
+    scan (bool): Create unique SSRC for scan attempts (KA9Q Only)
+    channel_filter (int/float): Set a high/lowpass frequency for a KA9Q channel.
 
     Arguments for SpyServer Client:
     ss_iq_path (str): Path to spyserver IQ client utility.
@@ -361,9 +363,9 @@ def get_sdr_iq_cmd(
         return _cmd
 
     if sdr_type == "KA9Q":
-        _cmd = ka9q_get_iq_cmd(sdr_hostname, frequency, sample_rate, scan)
+        _cmd = ka9q_get_iq_cmd(sdr_hostname, frequency, sample_rate, scan, channel_filter)
 
-        if dc_block:
+        if dc_block and ("KA9Q" not in sdr_type):
             _cmd += _dc_remove
 
         return _cmd

auto_rx/station.cfg.example

@@ -19,10 +19,9 @@
 #
 # RTLSDR - Use one or more RTLSDRs
 # 
-# EXPERIMENTAL / NOT IMPLEMENTED options:
+# Network SDR Server options:
 # SpyServer - Use an Airspy SpyServer
 # KA9Q - Use a KA9Q-Radio Server 
-# WARNING: These are still under development and may not work correctly.
 #
 sdr_type = RTLSDR
 
@@ -140,7 +139,7 @@ always_decode = []
 # STATION LOCATION #
 ####################
 # Used by the Sondehub Uploader, APRS Uploader, and by Rotator Control
-# Lat/Lon in decimal degrees, altitude in metres.
+# Lat/Lon in decimal degrees, altitude in metres (AMSL).
 # Note: You do not need to specify your home station accurately if you don't want to!
 # Feel free to use a position somewhere near your general area, that doesn't identify your home location.
 #

auto_rx/station.cfg.example.network

@@ -20,12 +20,11 @@
 #
 # RTLSDR - Use one or more RTLSDRs
 # 
-# EXPERIMENTAL / NOT IMPLEMENTED options:
+# Network SDR Server options:
 # SpyServer - Use an Airspy SpyServer
 # KA9Q - Use a KA9Q-Radio Server 
-# WARNING: These are still under development and may not work correctly.
 #
-sdr_type = SpyServer
+sdr_type = KA9Q
 
 
 #
@@ -38,7 +37,7 @@ sdr_type = SpyServer
 # If SDR type is either KA9Q or SpyServer, this defines the maximum number of parallel
 # decoding/scan tasks. On a RPi 4, ~5 tasks are possible.
 #
-sdr_quantity = 5
+sdr_quantity = 10
 
 
 #
@@ -48,7 +47,7 @@ sdr_quantity = 5
 # Is using KA9Q-Radio, the hostname of the 'radio' server (e.g. sonde.local) needs to be
 # defined, and the port number is unused.
 #
-sdr_hostname = localhost
+sdr_hostname = sonde.local
 sdr_port = 5555
 
 #
@@ -141,7 +140,7 @@ always_decode = []
 # STATION LOCATION #
 ####################
 # Used by the Sondehub Uploader, APRS Uploader, and by Rotator Control
-# Lat/Lon in decimal degrees, altitude in metres.
+# Lat/Lon in decimal degrees, altitude in metres (AMSL).
 # Note: You do not need to specify your home station accurately if you don't want to!
 # Feel free to use a position somewhere near your general area, that doesn't identify your home location.
 #
@@ -550,8 +549,8 @@ scan_delay = 10
 quantization = 10000
 # Decoder Spacing Limit - Only start a new decoder if it is separated from an existing decoder by at least
 # this value (Hz). This helps avoid issues where a drifting radiosonde is detected on two adjacent channels.
-# If you regularly encounter radiosondes on adjacent (10kHz) channels, then set this value to 5000.
-decoder_spacing_limit = 15000
+# For Network SDR systems, we set this to a lower value than the usual default of 15 kHz, as we have better channel filtering.
+decoder_spacing_limit = 5000
 # Temporary Block Time (minutes) - How long to block encrypted or otherwise non-decodable sondes for.
 temporary_block_time = 120
 # Upload when (seconds_since_utc_epoch%upload_rate) == 0. Otherwise just delay upload_rate seconds between uploads.