About the software you guys are using.. What does it do? When you zoom way in, is the image really pixilated?
The software that Tony and I are using on our Windows desktop and discussing the most is called GrLevel3 v2 which allows us to see level 3 ( L3 ) radar products. It allows us to get data directly from the NWS servers for free. To get the higher resolution data that level 2 ( L2 ) radar provides, you typically have to pay a 3rd party because the NWS charges for access to that data since it's much larger dataset to download.
What does it do? ... I thought is was obvious, it shows the various different NEXRAD level 3 radar products. There are about 11 different radar products with most of them providing up to 6 tilts each, some are single products ( no tilts ) and provides things like composite reflectivity ( all of the tilts averaged together so you can see the general intensity of the storm ), estimated rainfall ( one hour and storm total, the 3 hour has been discontinued ), echo tops ( shows how high the clouds are going ), vertical integrated liquids ( VIL, shows how much rain is within a specific column of air ).
Is it really pixelated... That depends on if we've set it to smooth the data or if we are just taking the "raw" level 3 data. GrLevel3 can use bilinear interpolation to help smooth out the data often allowing smaller details to show up easier even though the "raw" data may not exactly show it. Not all forms of radar data work well with smoothing... reflectivity ( shows intensity ) works pretty well but the velocity ( general wind speed/direction ) doesn't.
As for the amount of "pixelation" you may see... first you may need to know a little about the radar data itself. Unlike your monitor which shows pixels in rows and columns... Radar data is radial and shows the data is referred to be in bins ( or packets ). To get an better idea, images first a circle, then divide it in 1/2, then 1/4ths etc until each slice is relatively small, now divide it the other direction using circles withing the circle. When you are done dividing it in the two directions, you end up with sort of curved rectangles... the ones towards the center are really small and as you move further out... each one grows a little larger. Each of these "curved rectangles" are referred to as a bin. Since each bin that in close to the center is relatively small, the pixelation is relatively low but as you move further out, it gets a little larger.
Now why I used quotes around the word "raw" .... In reality, level 1 data is the actual raw data, level 2 and level 3 data is actually processed. Level 2 data is the high resolution data that provides 0.5dBZ resolution but it only has a handful of processed data products available to it directly from NWS, it's also a bit more noisy compared to level 3 data. Level 3 data is 10x lower resolution than level 2 providing 5.0dBZ or resolution and also a lot of other radar products when compared to the level 2 stuff. The primary advantage to using level 3 ( other than the number of products available ) is the download size of the data is in the 300-800kb size where the level 2 data is up to 14Mb per scan. If you are using a mobile device and paying for the amount of data you download, the level 3 is the obvious choice.
Ok.. here are some screenshots of the various images....
Level 3 data without any smoothing... notice as you get further away from the radar ( KOAX ) the bins ( aka "pixels" or packets ) get larger.
Here is the same level 3 data but I enabled "smoothing"
Now here is a screenshot from a different program called Radarscope that has "Super-Res" images which is a level 2 data that is already processed so the download size isn't as large as the full level 2 data is... a nice compromise so you save data but still are able to see the detail it provides. Level 2 reflectivity doesn't work well for "smoothing" since it contains more noise but it doesn't really need it as much either since it's 10x better resolution that level 3 data is. Please note that this is using a different color table than the other two shots, Radarscope doesn't allow much if any customization and GrLevel3 allows me to customize a lot.
Just a side note... Radarscope and GrLevel3 are paid products. The other program I mentioned the other day ( wX on Android and wXL23 on iPhone ) is a free program which has a lot of level 3 radar products available but it doesn't have any smoothing options, to make up for that it does provide two L2 products, reflectivity and velocity. Here is a screenshot of wX with L2 reflectivity ( aka SuperRes )
