Qimera Generate Overlap Report

Coverage Requirement

The grid used to generate the Overlap Report must contain the coverage property in order for the report to be successful. Ensure that the Coverage checkbox is checked when the grid is created:

How to Start

Right click on a Dynamic Grid, choose Grid Operations, click on Generate Overlap Report

What it does

This tool generates an ASCII text report outlining the amount that a given line is overlapped by other lines. It also provides a means to set a threshold which determines if a given line meets an overlap % criteria.

General Description

File Name

The file name of the ASCII text report.

Overlap Threshold

The % value used to determine if a given sonar file passes or fails the overlap requirement. The pass / fail status will be listed in the report file.

Limitations

Algorithm

The report generation algorithm is currently very simple and does not discriminate which portion of a swath is overlapped by other lines. This means that the overlap requirement could be met by a another line that runs directly over the top of the line in question, or crosses it at 90 degrees.

If a survey is conducted in a standard configuration, with each subsequent line overlapping and following the previous, the report will provide a meaningful measure of the amount that a given line was overlapped by others.

The Overlap report should be accompanied by an export of the Coverage layer for completeness and visual confirmation.

QPD Polygon

The QPD polygon used to approximate the bounds of the line’s data coverage is created during QPD processing. It’s a simplified approximation and does not represent an exact mask of each grid cell that contains data from the QPD in question. Small variations in Overlap calculation results may occur.

Report Information

In the header there is an outline of how the results are computed:

Each line in the report corresponds to one QPD file.

A grid cell is considered to be overlapped if it has a coverage value of 2 or greater.

The overlap threshold is the percentage of cells in the QPD polygon that must be overlapped for the QPD to be considered as passing.

A QPD is considered to have passed if the percentage of overlapped cells in the QPD polygon is greater than or equal to the specified overlap threshold.

There is also a header line outlining the comma delimited results for each line:

QPD filename,

# of grid cells within QPD polygon,

# of cells in polygon with coverage >= 2,

% with coverage >= 2,

Result (Pass/Fail)

Sample Report

CODE

# Qimera Line Overlap Report
# Generated by Qimera
# Date: Tue Nov 25 11:17:42 2025
# 
# Each line in the report corresponds to one QPD file.
# A grid cell is considered to be overlapped if it has a coverage value of 2 or greater.
# The overlap threshold is the percentage of cells in the QPD polygon that must be overlapped for the QPD to be considered as passing.
# A QPD is considered to have passed if the percentage of overlapped cells in the QPD polygon is greater than or equal to the specified overlap threshold.

   Specified Overlap Threshold: 33
   Grid File: /Users/QPS/QPS-Data/Projects/overlap-project/GridData/Dynamic Grid/Dynamic Grid.dyngrid
   Total QPDs Analyzed: 45
   QPDs Passing: 39 

The columns are:
QPD filename, # of grid cells within QPD polygon, # of cells in polygon with coverage >= 2, % with coverage >= 2, Result (Pass/Fail)
0000_20130510_170808_Heron,181,181,100.00,Pass
0001_20130510_171716_Heron,832,826,99.28,Pass
0002_20130510_175716_Heron,628,628,100.00,Pass
0003_20130510_183716_Heron,946,933,98.63,Pass
0004_20130510_191716_Heron,415,414,99.76,Pass
0005_20130510_195716_Heron,938,911,97.12,Pass
0006_20130510_203716_Heron,891,884,99.21,Pass
0007_20130510_210639_Heron,25833,15975,61.84,Pass
0008_20130510_211158_Heron,48885,8807,18.02,Fail
0009_20130510_211947_Heron,83772,9072,10.83,Fail
0010_20130510_212837_Heron,44675,6752,15.11,Fail
0011_20130510_213211_Heron,44559,8637,19.38,Fail
0012_20130510_213908_Heron,47726,8190,17.16,Fail
0013_20130510_214635_Heron,33905,7014,20.69,Fail
0014_20130510_215257_Heron,10625,4139,38.96,Pass
0015_20130510_215430_Heron,30209,17219,57.00,Pass
0016_20130510_215852_Heron,65251,46808,71.74,Pass
0017_20130510_220939_Heron,6278,6004,95.64,Pass
0018_20130510_221328_Heron,960,957,99.69,Pass
0019_20130510_221555_Heron,29518,22920,77.65,Pass
0020_20130510_222622_Heron,19929,16188,81.23,Pass
0021_20130510_222908_Heron,10489,7622,72.67,Pass
0022_20130510_223117_Heron,30745,15693,51.04,Pass
0023_20130510_223954_Heron,2523,2510,99.48,Pass
0024_20130510_224149_Heron,918,918,100.00,Pass
0025_20130510_224255_Heron,20976,15578,74.27,Pass
0026_20130510_225029_Heron,24262,21568,88.90,Pass
0027_20130510_225457_Heron,6314,6230,98.67,Pass
0028_20130510_225750_Heron,21950,9727,44.31,Pass
0029_20130510_230330_Heron,17480,12327,70.52,Pass
0030_20130510_230854_Heron,22,22,100.00,Pass
0031_20130510_231104_Heron,3804,3353,88.14,Pass
0032_20130510_231435_Heron,2307,2261,98.01,Pass
0033_20130510_231618_Heron,3434,3120,90.86,Pass
0034_20130510_232155_Heron,1790,1757,98.16,Pass
0035_20130510_232248_Heron,6427,5843,90.91,Pass
0037_20130510_234554_Heron,1643,1352,82.29,Pass
0038_20130510_234800_Heron,4194,2127,50.72,Pass
0039_20130510_235537_Heron,700,529,75.57,Pass
0040_20130510_235941_Heron,1246,561,45.02,Pass
0041_20130511_000208_Heron,705,484,68.65,Pass
0042_20130511_000542_Heron,3846,2631,68.41,Pass
0043_20130511_000859_Heron,596,591,99.16,Pass
0044_20130511_001121_Heron,3958,3218,81.30,Pass
0045_20130511_001659_Heron,12581,6710,53.33,Pass