44 lines
1.6 KiB
Plaintext
44 lines
1.6 KiB
Plaintext
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bladeRF support
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There is basic support for the bladeRF included in dump1090-fa.
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It uses the same demodulator as the regular rtlsdr version and it does not
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take advantage of the bladeRF's improved sampling rate or FPGA (but see below)
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To use it:
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$ dump1090-fa --device-type bladerf --gain 66 (.. other options ..)
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The bladeRF has sensitivity problems when receiving ADS-B and will benefit
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from all the gain you can give it. 66dB is the maximum configurable gain on
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the board itself, you may want to add an external LNA too.
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bladeRF custom FPGA bitstream
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-----------------------------
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The package includes a custom FPGA bitstream for the bladeRF which can
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improve ADS-B reception with dump1090.
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It adds a Fs/4 mixer step to avoid the DC offset of the bladeRF, and
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decimate-by-8 downsampling step to improve sensitivity. Some of the bladeRF
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parameters need to be adjusted so that it produces correctly tuned/downsampled
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data in the form that dump1090 is expecting.
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To use it:
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$ dump1090-fa --device-type bladerf --gain 66 \
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--bladerf-fpga /usr/share/dump1090-fa/bladerf/decimate8-x40.rbf \
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--bladerf-decimation 8 \
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--bladerf-bandwidth 14000000 \
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--freq 1085200000 \
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(other options ...)
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The bladeRF will be configured for a 19.2MHz sampling rate and will tune to
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1085.2MHz so that the 1090MHz signal appears around 4.8MHz in the baseband
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samples. The FPGA Fs/4 mixing step shifts the baseband signal so that it is centered
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around 0, and the FPGA downsampling step produces samples at 2.4MHz, which is what
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dump1090 is expecting.
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This FPGA bitstream is built for the 40kLE bladeRF.
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