jks

Hi Larry. If you're talking about the kiwirecorder and/or kiwi_nc (netcat) Python programs as we discussed in email then the situation is a bit different from the browser interface on the Kiwi itself (Ron's answer is excellent).

When you use the "--wf" option with kiwiclient (i.e. as used by the "wf:" target in the Makefile) what happens is the Kiwi sends waterfall data at zoom level zero (0 - 30 MHz) at a 1 Hz update rate by default. The data is 1024 bins wide which is the size of the waterfall FFT and also how many bins are seen on the browser interface. So at zoom=0 each bin represents roughly 30 kHz of spectrum (30 MHz / 1024 bins ~= 30 kHz).

I recall you said your analysis application wanted 512 bins of input data. So one thing you could do is simply throw away the first 512 bytes of output data on each update. Then you'd be left with 512 bins of data for 15 - 30 MHz. Now there is a --zoom option in kiwiclient as well but it turns out it isn't implemented quite correctly at the moment. It would be easy to fix however and then together with the -f option to set the center frequency you could set whatever power-of-two zoom sub-multiple of 30 MHz you wanted. For example as Ron said set the frequency to 22.5 MHz (the middle of the 15-30 MHz segment) and zoom=1. Then you'd get 1024 bins beginning at 15 MHz each with about 15 kHz of resolution.

Okay, I think kiwirecorder resampling works now. Update from https://github.com/jks-prv/kiwiclient.git (master or jks-v0.1 branch) and use the new "-r N" or "--resample N" option where N is the new sample rate in Hz. Works with regular and IQ-mode recordings. See the "resample" and "resample_iq" example targets in the Makefile.

I will improve the input parsing for this field to prevent the problem in the future.

For those of you who struggle like me to get regular expressions working this is the greatest thing since sliced bread: https://regex101.com

Subtle problem: compared to 8073, 8074 and 8075 are both configured with an extra closing parenthesis at the end of the "Location (lat, lon)" field on the sdr.hu tab of the admin page, i.e. "gps=(53.886303,-2.621231))"

Since Christoph's new Kalman filter eliminates GPS outlier solutions the accumulated values from a long running shadow map will be a lot clearer. The az/el shadow map below from the gps tab on the admin page is after about 30 hours of running. You can clearly see that I live in a tall apartment building with a west facing view as everything from 0 to 180 degrees is blocked by the shadow of the building (the antenna is on the metal handrail [ground plane of sorts] of the balcony). The "polar hole" is to the south since I'm in the southern hemisphere and I have mountains to the west.