SeaWiFS Reprocessing 5 Validation Analysis
The effect of the proposed SeaWiFS reprocessing changes on the comparison
with
in situ data are presented here. The difference in N between the operational and reprocessing sets is due to additional data added since the last time the operational set was run. Given the large sample sizes, the statistics should be comparable despite the differnce in N.
A description of the methods employed for these analyses, with minor modifications, can be found in Volume 10, Chapter 7 of the
SeaWiFS Post Launch Technical Memorandum Series.
There are approximately radiance and chlorophyll matchups which pass all exclusion criteria.
Statistics Summary:
| Current Operational Processing |
Proposed Reprocessing |
|---|
|
Band
|
N
|
Mean Ratio*
|
%% Difference**
|
Bias
|
rms+
|
| nLw_412 |
491 |
0.8748 |
22.564 |
-0.1477 |
0.4425 |
| nLw_443 |
593 |
0.931 |
17.201 |
-0.0898 |
0.3546 |
| nLw_490 |
551 |
0.955 |
14.140 |
-0.0659 |
0.3059 |
| nLw_510 |
424 |
0.9584 |
13.476 |
-0.0542 |
0.3030 |
| nLw_555 |
593 |
0.990 |
14.5190 |
-0.0132 |
0.2308 |
| nLw_670 |
571 |
1.0764 |
47.836 |
0.0012 |
0.0731 |
| chl |
1267 |
1.106 |
35.908 |
0.104 |
0.7085 |
|
|
N
|
Mean Ratio*
|
%% Difference**
|
Bias
|
rms+
|
| 523 |
0.9203 |
22.7320 |
-0.0683 |
0.3384 |
| 625 |
0.9572 |
17.189 |
-0.0316 |
0.2696 |
| 625 |
0.947 |
14.5180 |
-0.0443 |
0.2210 |
| 490 |
0.932 |
14.684 |
-0.0546 |
0.2110 |
| 625 |
0.9410 |
16.698 |
-0.0412 |
0.1785 |
| 590 |
0.9134 |
50.897 |
-0.0098 |
0.0678 |
| 1392 |
0.9610 |
36.473 |
-0.0456 |
0.7303 |
|
* arithmetic mean of all satellite / in situ ratios
** median absolute percent difference
+ sqrt ( &sum(satellite - in situ)^2 / n )
chlorophyll data were log transformed prior to statistics calculation
The Plots
Discussion
Overall, there was little change with the in situ comparisons between operational (reprocessing 4) and the proposed reprocessing results. The biases were slightly reduced with the proposed reprocessing, although the median percent difference (absolute) are nearly identical between the two.
