Inquiries about harmonic decomposition of the "LSHA.out" file("LSHA.out" 파일의 조화분해에 대한 문의)

1

hello.

I wrote this because I had a question.
If I and J are specified in C83, the harmonic decomposition result of the specified vertex is saved in LSHA.out after the simulation is completed.
After completing the experiment, time series data were separately extracted from the vertices specified in C83 and harmonic decomposition was performed, and the results were somewhat different from the results of LSHA.out.
How are the results saved in LSHA.out calculated?

안녕하세요.

궁금한 점이 있어 글을 작성하게 되었습니다.
C83에서 I, J를 지정하면 모의 완료 후 지정한 정점의 조화분해 결과 값이 LSHA.out에 저장됩니다.
실험 완료 후 C83에서 지정한 정점들에서 시계열 자료를 별도로 뽑아 조화분해한 결과, LSHA.out의 결과와 다소 차이가 있었습니다.
LSHA.out에 저장되는 결과는 어떻게 산정되는 건가요?

2

Hi Sadam,
We were wondering how did you extract data from LSHA.out? The output in LSHA.out for the analysis of water surface elevation includes amplitude, phase, which are calculated based on least squares method. In the EFDC+ code, this procedure is done by subroutine LSQHARM.

For the details, you may take a look at the subroutine from GitHub following: https://github.com/dsi-llc/EFDCPlus/blob/main/EFDC/lsqharm.f90.
The calculation for water surface elevation analysis is from the line 257 to 298, followed by the analysis of salinity, external mode horizontal velocity.