Parameters tab - voxo22/hackrf-spectrum-analyzer GitHub Wiki

Timestamp

The Timestamp checkbox enables the display of a current date and time in the upper left corner of the spectral chart. If you are making a VIDEO recording of the spectrum, the timestamp will be part of it.

Lines Thickness

You can choose different line thicknesses for the curves. Thicker lines can be useful if you are recording VIDEO in MP4 format.

Peak Fallout Time

In the case of analyzing short amplitude pulses, various hold methods can be applied to the PEAK curve. While the increase in amplitude is recorded immediately (similar to REALTIME), the PEAK curve holds its position on the chart for a certain time. PEAK fallout time determines how long in seconds the peak amplitude will fall to its "minimum" until another pulse at the same frequency arrives. In practice, this means that the PEAK curve is constantly "falling", this parameter determines how fast.

Note: This parameter is only displayed if the PEAK curve is displayed.

Peak Fall Threshold

In the case of analyzing short amplitude pulses, various hold methods can be applied to the PEAK curve. While the increase in amplitude is recorded immediately (similar to REALTIME), the PEAK curve holds its position on the chart for a certain time. PEAK fall threshold time determines how smoothly the peak amplitude will fall to its "minimum" until another pulse at the same frequency arrives. In practice, this means that the PEAK curve is constantly "falling", this parameter determines how many fall steps are to be skipped.

Note: This parameter is only displayed if the PEAK curve is displayed.

Peak Hold Time

In the case of short-amplitude pulse analysis, various holding methods can be used for the PEAK curve. While the increase in amplitude is recorded immediately (similar to REALTIME), the PEAK curve will hold its position in the graph for a certain time. Peak hold time is the time during which the curve will hold its maximum PEAK value (it will not gradually fall). If you set this parameter to a value greater than 0, the PEAK will be held for a given number of seconds. This is ideal, for example, if you want to make a DATA record and set a second or minute periodicity. In the case of a second, set Peak hold time to 1, so you will have the MAX of all amplitudes be held for every second, which will then be saved in the data file. In the case of a minute periodicity, set Peak hold time to 60, this MAX value will be held for a whole minute. However, during this time, an amplitude can always arrive at a certain frequency that will raise the PEAK curve. However, it will always be held for a given number of seconds.

Note: This parameter is only displayed if the PEAK curve is displayed.

Persistent Decay Rate

A persistent chart is a specific type of spectral analysis that displays the frequency of occurrence of an amplitude at a given frequency in color. In order to capture rapid amplitude changes in some cases, a certain display hold time is applied. The decay rate parameter determines the time in seconds at which the colored points disappear from the chart.

Note: This parameter is only displayed if a PERSISTENT chart is displayed.

Average Iterations

This parameter determines the number of averaging iterations for displaying the AVERAGE curve. Continuous amplitudes are preserved by averaging and sporadic ones are filtered. The iterations are calculated from REALTIME data, you can choose to average from 20, 50 or 80 iterations. The higher the number of iterations, the smoother the display, but short pulses will definitely be filtered out.

Note: This parameter is only displayed if the AVERAGE curve is displayed.

Average Offset

With this slider the AVERAGE curve can be "moved" along the Y-axis, as in some cases it can undesirably hide below the -100 dBm limit.

Note: This slider is only displayed if the AVERAGE curve is displayed.

Frequency Allocation Bands

The frequency allocation bands drop-down list allows you to select various user-defined frequency band descriptions. The drop-down list entries are loaded automatically based on the presence of CSV files in the "freq" folder. They are sorted alphabetically by file name. If you want to prioritize a particular file to be displayed after startup, rename it so that it is first in the alphabet. Frequency band descriptions are a very useful tool for navigating the spectrum. You can create your own by simply modifying existing files. The CSV file has the following format (for example):

"Country";"Frequency Range";"Applications";"Color"
"SK";"5900 - 6200 kHz";"49m SW radio";"#0000FF"
"SK";"21000 - 21450 kHz";"15m HAM";"#DEB887"
"SK";"87.500 - 108.000 MHz";"FM radio";"#9400D3"
"SK";"174.000 - 240.000 MHz";"DAB+";"#FF69B4"
"SK";"431.000 - 435.000 MHz";"ISM 433";"#DC143C"
"SK";"703.000 - 713.000 MHz";"LTE700/O2/uplink";"#00658c"
"SK";"713.000 - 723.000 MHz";"LTE700/Telekom/uplink";"#e70073"
"SK";"723.000 - 733.000 MHz";"LTE700/Orange/uplink";"#ff6500"
"SK";"758.000 - 768.000 MHz";"LTE700/O2/downlink";"#00658c"
"SK";"768.000 - 778.000 MHz";"LTE700/Telekom/downlink";"#e70073"
"SK";"778.000 - 788.000 MHz";"LTE700/Orange/downlink";"#ff6500"

You can define the frequency range in kHz or MHz. Specify the text description to be displayed on the bar. The "/" character creates a new line. The last parameter specifies the color shade of the bar in HEX code. The bars are semi-transparent.