Those of us who already commented here mustn’t be “cool”?..
Any autoscaling on these graphs makes the “with” and “without filter” comparisons less useful. A fixed scale (one that identifies SNR by color intensity) would be preferable. Ideally they’d use the full spectrum of color to denote intensity (I’m thinking like a weather radar map)…
I checked the Aliexpress above site.
Although the photo displayed with option “with battery” shows a VNA in a black plastic case, there is no mention of case (in writing) anywhere. I was about to order it, but stopped as I dont want one without a case. I will wait till you receive it and tell if the “with battery” option you ordered is with or without case.
The photos for option “without battery” clearly shows no case is provided.
INPUT Input CSV file. (may be a .csv.gz)
OUTPUT Output image. (various extensions supported)
-h, --help show this help message and exit
--offset OFFSET_FREQ Shift the entire frequency range, for up/down
--ytick TIME_TICK Place ticks along the Y axis every N
--db DB_LIMIT DB_LIMIT
Minimum and maximum db values.
--compress COMPRESS Apply a gradual asymptotic time compression. Values >
1 are the new target height, values < 1 are a scaling
--palette PALETTE Set Color Palette: default, extended, charolastra,
Efficiently render a portion of the data. (optional) Frequencies can take
G/M/k suffixes. Timestamps look like "YYYY-MM-DD HH:MM:SS" Durations take
--low LOW_FREQ Minimum frequency for a subrange.
--high HIGH_FREQ Maximum frequency for a subrange.
--begin BEGIN_TIME Timestamp to start at.
--end END_TIME Timestamp to stop at.
--head HEAD_TIME Duration to use, starting at the beginning.
--tail TAIL_TIME Duration to use, stopping at the end.
Agreed, and there are good reasons for that. The newer version of Spektrum has avg and smoothing if needed to run for a long period of time. Just an idea for those who may not have tried or heard about it before, - another tool in the box for perspective.
The range used is shown in the output from the heatmap command as the z parameter
It finds the highest and lowest figures in the csv and uses them.
eg from a scan I did:
./heatmap.py scan.csv scan.png
x: 4576, y: 60, z: (-37.070000, 4.400000)
I suggest using something like -40 to 10 as a fixed scale so:
./heatmap.py --db -40 10 scan.csv scan.png