Grlevelx

National Weather Service

Grlevelx - Gibson Ridge Software, LLC (GRS) was created in March 2005 and produces viewers for weather radar data. GRS applications include GRLevel2 for viewing Level II radar data and GRLevel3 for viewing Level III data. Both viewers feature high speed, high quality radar displays with an intuitive user interface. Grlevelx has taken tracking storms to a completely new level. The software allows the user to look at live data and analyze it on spot. It has helped professionals in every aspect of meteorology, from detecting early tornado signs, to forecasting hurricane strength days out. Grlevelx also allows the user to take a 3D Image of a super cell thunderstorm. This gives us information concerning hail size and storm strength. In the end, the significance of this software is not just the new wave of technology it’s bringing to the meteorology community, but the lives it will save. The early warning system along with live interactive radar will bring weather forecasting to a new level. All GRS applications are written in multithreaded C++ using the base Windows APIs for speed and efficiency.



Gibson Ridge Software's Owner is Michael Scott Gibson, a software design engineer with two decades of experience writing PC applications and operating system software. His primary specialty is graphics and font technology, from the API down to the driver level, and is the inventor or co-inventor in three patents related to that work.

Overview

 * GRLevel2 is a Windows viewer for live and archived NEXRAD Level II data. Base reflectivity, base velocity, storm relative velocity, and spectrum width sweeps for all radar tilts are available. High speed zooming and panning allows you to quickly focus in on the area of interest.


 * GRLevel3 is a Windows viewer for live NEXRAD Level III data from the NWS Radar Product Central Collection Dissemination Service. Many Meteorologists and Storm chasers use this software to locate super-cell tornadoes while chasing.




 * GRLevel2 Analyst Edition is an advanced NEXRAD Level II analysis application. It features a high quality volumetric display and several high resolution reflectivity-derived graphical products in addition to the standard Level II data products.

Reflectivity Derivatives in GR2Analyst
GR2Analyst processes each radar volume and derives five high resolution 2D products from base reflectivity:

•Echo Tops(ET)-The height above ground of the center of the radar beam using the tilt, or scan, that contains the highest elevation where reflectivity greater than 18 dBZ can be detected.

•Vertically Integrated Liquid (VIL)-Vertically-Integrated Liquid water. A property computed by RADAP II and WSR-88D units that takes into account the three-dimensional reflectivity of an echo. The maximum VIL of a storm is useful in determining its potential severity, especially in terms of maximum hail size.

•VIL Density- VIL is a function of reflectivity, and converts reflectivity data into an equivalent liquid water content value based on studies of drop-size distribution and empirical studies of reflectivity factor and liquid water content (Amburn 1996). The general equation for VIL as used with the WSR-88D is:

$$VIL = \sum 3.44\times 10^{-6} \left[ \frac{\left(Z_i + Z_{i+1}\right)}{2} \right ]^{4/7} \Delta h$$

The high resolution derivative products are calculated on 1 km x 1° x 230 km grid with 256 data levels. They automatically account for the current storm motion vector setting and are recalculated when the vector is changed. In addition, the POSH and MEHS algorithms use GR2Analyst's environmental database of 0C and -20C heights. You need to enter these temp/heights accurately in order to get correct hail algorithm results. The algorithm uses any temp/height data within 48 hours of the volume scan time. If no recent data is found, it defaults to 10,000ft and 20,000ft for the heights.



Although they make it very easy for the consumer to buy they recommend that you download the 21 day trial period before making a purchase.



System Requirements
GR2Analyst has significant system requirements: •	Windows XP or above •	DirectX 9.0c •	Graphics adapter with shader model 2.0 support With the exception of the volume renderer, most shader model 2.0 video cards will be sufficient to run GR2Analyst. The volume renderer is both CPU and GPU intensive, requiring fast a CPU and mid to high end graphics adapters. Recommended requirements for the volume renderer: •	Pentium4 2.26GHz or higher •	512MB of system memory •	At least 128MB of dedicated video memory •	256-bit video memory bus -or- a high speed 128-bit video memory bus •	8 or more pixel shader units