Dynamic SNR Map for all kiwiSDR receivers present in sdr.hu - Full-screen version

Be patient, the software is being upgraded, data may be wrong! Reload the page with CTRL -r to use the latest version!

NEW: you can now hide bad SDRs by double clicking on circles: the circle will disappear. On the next reload of the page you'll see it blacked out and by double-clicking again you'll reactivate it.

Please don't ask for scores to classify SDRs, a single number cannot convey how well a receiver/antenna is working: maybe the best reception quality predictor is how widely the SNR oscillates during the day and of course by a low level background noise!

This map is dynamically updated every hour for all kiwiSDR receivers worldwide. Blue means really low SNR, yellow is average and red stands for an excellent value. The size of the circles is also proportional to the SNR value for that band. All measurements are completed within 2 minutes, so the values may be considered concurrent. The band of interest may be selected by pressing the relative control on the lower left side of the map (this only changes how the circles are colored/sized and the info shown hovering on a circle). Average or last values for SNR are selectable with the button on the center left. Hovering on a circle shows the last/avg results of the SNR/noise estimation for the selected band:
0-2 MHz, 2-10 MHz, 10-20 MHz and 20-30MHz.

Black circles represent receivers that did not reply to the last measuring request.

Click on a circle to get the SNR history (one week at most) on all bands along with the day/night overlay specific of that receiver location. A background noise plot is also accessible by clicking on a link. The lines represent running average interpolating functions with window equal to 5 data points. A full screen map can be shown by clicking the link on the title.

The idea originally started to improve upon linkfanel's (Pierre Ynard) original SNR map. Each SNR value is computed by estimating the background and peak levels within the received waterfall. This SNR estimation may be skewed by local, non-uniform, noise. For instance, a series of noise peaks is not easily distinguishable from the 9/10-kHz separated MW stations. Such noise is produced by many routers and cheap switching power supplies. The quad band concept emerged from the observation that many SDR, though excellent on LF and MW, show a terrible decrease of performance on higher frequencies towards 28MHz. Another issue that this page tries to address is the low updating frequency of the previous SNR map.

Read this for a short introduction to the method [PDF]

have fun!

marco / IS0KYB

-- if you have any comment, ideas or you just want to say hi, feel free to send an email to cogoni AT gmail DOT com or look for zabow on IRC #kiwisdr

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BEWARE that kiwiSDRs allow remote passwordless access from specific IPs, read this carefully!