Configuration

Config Parameters

Config field

Example entry

Description

site_id

sas

3-letter standard ID of the radar.

gps_octoclock_addr

addr=192.168.10.131

IP address of the GPS Octoclock.

device_options

recv_frame_size=4000

UHD USRP device arguments.

main_antenna_count

16

Number of physical main array antennas, regardless of N200 status.

intf_antenna_count

4

Number of physical interferometer antennas, regardless of N200 status.

n200s
{
“addr” : “192.168.10.100”,
“rx_channel_0” : “m0”,
“rx_channel_1” : “i0”,
“tx_channel_0” : “m0”
}, {
“addr” : “192.168.10.101”,
“rx_channel_0” : “m1”,
“rx_channel_1” : “i1”,
“tx_channel_0” : “m1”
}, …

List of all N200s, both active and not. The value for each channel maps to a physical antenna of the radar, with the first digit either “m” for main array or “i” for interferometer array. TX channels can only be connected to the main array. The numbers after the array designator are the antenna index into the array. The antenna index must lie between 0 and the [main|intf]_antenna_count fields above. The ordering of the N200 parameters doesn’t matter.

addr (n200s)

192.168.10.100

IP address of the specified N200.

rx_channel_0 (n200s)

m0

Antenna number connected to receive channel 0 of the N200. The first character indicates the array, and the rest the index of the antenna. Set to “” if the channel is disconnected.

rx_channel_1 (n200s)

i0

Antenna number connected to receive channel 1 of the N200. The first character indicates the array, and the rest the index of the antenna. Set to “” if the channel is disconnected.

tx_channel_0 (n200s)

m0

Antenna number connected to transmit channel 0 of the N200. The first character indicates the array, and the rest the index of the antenna. The array specifier must be “m”, if set. Set to “” if the channel is disconnected.

main_antenna_spacing

15.24

Distance between antennas (m).

intf_antenna_spacing

15.24

Distance between antennas (m).

min_freq

8.00E+06

Minimum frequency we can run (Hz).

max_freq

20.00E+06

Maximum frequency we can run (Hz).

min_pulse_length

100

Minimum pulse length (us) dependent upon AGC feedback sample and hold.

min_tau_spacing_length

1

Minimum length of multi-pulse increment (us).

min_pulse_separation

125

The minimum separation (us) before experiment treats it as a single pulse (transmitting zeroes and not receiving between the pulses). 125 us is approx two TX/RX times.

max_tx_sample_rate

5.00E+06

Maximum wideband TX rate each device can run in the system.

max_rx_sample_rate

5.00E+06

Maximum wideband RX rate each device can run in the system.

tx_subdev

A:A

UHD daughterboard string which defines how to configure ports. Refer to UHD subdev docs.

main_rx_subdev

A:A A:B

UHD daughterboard string which defines how to configure ports. Refer to UHD subdev docs.

intf_rx_subdev

A:A A:B

UHD daughterboard string which defines how to configure ports. Refer to UHD subdev docs.

pps

external

The PPS source for the system (internal, external, none).

ref

external

The 10 MHz reference source (internal, external).

overthewire

sc16

Data type for samples the USRP operates with. Refer to UHD docs for data types.

cpu

fc32

Data type of samples that UHD uses on host CPU. Refer to UHD docs for data types.

gpio_bank_high

RXA

The daughterboard pin bank to use for active-high TR and I/O signals.

gpio_bank_low

TXA

The daughterboard pin bank to use for active-low TR and I/O signals.

atr_rx

0x0006

The pin mask for the RX-only signal.

atr_tx

0x0018

The pin mask for the TX-only signal.

atr_xx

0x0060

The pin mask for the full-duplex signal (TR).

atr_0x

0x0180

The pin mask for the idle signal.

lo_pwr

0x0600

The pin mask for the low-power signal.

agc_st

0x1800

The pin mask for the AGC signal.

tst_md

0x6000

The pin mask for the test mode signal.

max_usrp_dac_amplitude

0.99

Amplitude of the highest allowed USRP TX sample (V).

pulse_ramp_time

1.00E-05

The linear ramp time for the pulse (s).

tr_window_time

6.00E-05

How much windowing on either side of pulse is needed for TR signal (s).

agc_signal_read_delay

0

Hardware dependent delay after seq is finished for reading of AGC and low power signals (s).

usrp_master_clock_rate

1.00E+08

Clock rate of the USRP master clock (Sps).

max_output_sample_rate

1.00E+05

Maximum rate allowed after downsampling (Sps).

max_filtering_stages

6

The maximum number of filtering stages.

max_filter_taps_per_stage

2048

The maximum total number of filter taps for all frequencies combined. This is a GPU limitation.

router_address

tcp://127.0.0.1:6969

The protocol/IP/port used for the ZMQ router in Brian.

realtime_address

tcp://eth0:9696

The protocol/IP/port used for realtime.

ringbuffer_name

data_ringbuffer

Shared memory name for ringbuffer.

ringbuffer_size_bytes

200.00E+06

Size in bytes to allocate for each ringbuffer.

data_directory

/data/borealis_data

Location of output data files.

log_handlers
{
“console” : {},
“logfile” : {},
“aggregator” : {},
}

Fields for controlling the Borealis loggers. Supported log handlers are console logging, JSON file logging, and aggregator log forwarding.

console (log_handlers)
{
“enable” : true,
“level” : “INFO”
}

An enable flag and log level for the console log handler. Supported levels are “DEBUG”, “VERBOSE”, “INFO”, “WARNING”, “ERROR”, “NOTSET”, and “CRITICAL”, or a numeric value between 0 and 50.

logfile (log_handlers)
{
“enable” : true,
“level” : “VERBOSE”,
“directory” :
“/data/borealis_logs”
}

An enable flag, log level, and path to a directory for storing log files in. The log levels are the same as for console above.

aggregator (log_handlers)
{
“enable” : true,
“level” : “INFO”,
“addr” : “0.0.0.0”,
“port” : “12201”
}

An enable flag, log level, and network address and port for aggregator log handling. The logs are then sent over the network for collection by an aggregator such as a graylog server. The log levels are the same as for console above.

hdw_path

/usr/local/hdw

Path to locally cloned SuperDARN hardware repository.

Testing a config file

A test script is available for verifying the fields of your configuration file. This script is detailed further here.

Example configurations

There are several instances when you’ll need to modify this file for correct operation.

  1. One of your main array antennas is not working properly (broken coax, blown lightning arrestor, etc)

    The N200(s) with RX and TX channels connected to that antenna should have those channels set to "". This will disable transmission and reception on the antenna, while preserving the correct phasing for beamforming on other channels.

  2. One of your interferometer array antennas is not working properly (broken coax, blown lightning arrestor, etc)

    The N200 with an RX channel connected to that antenna should have that channel set to "". This will disable reception from the antenna, while preserving the correct phasing for beamforming data from other channels.

  3. One of your transmitter’s transmit paths is not working, but the receive path is still working properly

    The tx_channel_0 field for the associated N200 should be set to "". This will disable the transmission channel on the bad transmit path.

  4. One of your transmitter’s receive paths is not working, but the transmit path is still working properly

    The rx_channel_# flag for the associated N200 should be set to "". This will disable the receive channel on the bad receive path.

  5. One of your transmitters is not working at all

    Ensure that no N200s have a channel set to use that corresponding antenna. For example, if the transmitter for antenna 7 of the main array is broken, make sure no rx_channel_# or tx_channel_0 fields are set to "m7".

  6. One of your N200s is not working properly and you’ve inserted the spare N200

    Add an entry for the replacement N200, and copy rx_channel_0, rx_channel_1, and tx_channel_0 fields from the broken N200. Make sure that the cables are transferred over, and verify that the cabling matches with the antennas specified for each channel. The configuration for the broken N200 can be set to "" for each channel. If all channels are set to "", the N200 is ignored.

  7. One of your N200s is not working properly but you’re located remotely and cannot insert the spare N200

    This particular N200 will have to be deactivated. To do this, set all channel fields to "".

  8. You have a non-standard array

    One example of a non-standard array would be a different number of interferometer antennas than four. To implement this, modify the individual N200 entries to specify which N200s are connected to interferometer antennas. Additionally, set the main and interferometer antenna count parameters to the number of physical antennas in each array.

  9. You want to change the location of ATR signals on the daughterboards

    This can be done by changing the values of the following config parameters: atr_rx, atr_tx, atr_xx, atr_0x, tst_md, lo_pwr, agc_st. The value atr_rx = 0x0006 means that the ATR_RX signal will appear on the pins 1 and 2 (referenced from 0). I.e. every bit that is a ‘1’ in this hex value indicates which pin the signal will appear on.

  10. You want to change the polarity of the ATR signals on the daughterboards

    This can be done by swapping the values of the two config parameters: gpio_bank_high and gpio_bank_low. The default is for active-high signals to be on the LFRX daughterboard. This is done by setting gpio_bank_high to RXA. The same signals, but active-low, are by default located on the LFTX daughterboard.

  11. You would like to make a test-system with only one N200 and don’t have any Octoclocks

    This can be done by changing the following parameters:

    1. n200s - Set tx_channel_0, rx_channel_0, and rx_channel_1 fields for only one N200. All others should have their channels set to "".

    2. pps and ref - These should both be set to internal, as you don’t have an Octoclock to provide a reference PPS or 10MHz reference signal.