CVM S4 Testing

We have identified points where CVM-S4 queries are stateful, specifically in the GTL region (~100m depth). By this, we mean that if we query the same point twice, CVM-S4 (and UCVM) returns different Vp, Vs, and rho properties for each query.

To investigate this, we will run some tests to determine if all CVM-S4 regions are stateful, or only the GTL regions. We will also look at how large the differences

Search Regions

Define two search regions, one in LA Basin where CVM-S4 has a GTL define. The second in the mojave where it is CVM-S4 background model. We will discretize at ~10.0m resolution. Basedon this link: Decimal Degrees, we'll descritze at 0.0001 resolution.

Search plans

We will use ucvm makemesh.sh script to create query points for each of these regions. We'll define a search layer from 80m to 120m at 10m resolution to determine whether the alternative values are at a single depth, or in a range of depths. We will add the original observed points to end of the file to ensure we reproduce the initial observations.

• Single query version

The first UCVM query will be a single query call for each point. It will output the expect ucvm results with useful results in the final columns.

• Double query version

The second ucvm query will contain duplicate points for each query. We will expect that in some cases, especially the observed data points above, the second query will return different values

• Triple query version

The third ucvm query will contain three duplicate points for each query. We will determine whether the second and third calls will create duplicates also.

Analysis

Post-processing scripts will determine:

• Total number of points in each file:
• Number of point in which first and second query are different
• Percent difference between first and second queries
• Location of points that produce differences
• Number of points in which second and third query are different
• Number of points in which first and third query are different

LABasin GTL Region 

 34.5 -118.5
 33.5 -117.5

in KML:

<coordinates>
-117.5,33.5,0 -117.5,34.5,0 -118.5,34.5,0 -118.5,33.5,0 -117.5,33.5,0 
</coordinates>

Background Region

35.5 -117.5
34.4 -116.5

<coordinates>
-116.5,34.5,0 -116.5,35.5,0 -117.5,35.5,0 -117.5,34.5,0 -116.5,34.5,0 
</coordinates>

makemesh

We use the ucvm makemesh script to create the query points.

Related Entries

• UCVM