Outline and Features of HAPI2: Second Generation of the HITRAN Application Programming Inteface

The HITRAN Application Programming Interface (HAPI) [1] was originally designed to facilitate the line-by-line data acquisition from the HITRANonline [2,3] information system, and for generating the spectral functions from these data. Providing tools to model single-layer transmittance in gaseous media, HAPI becomes a useful starting point for more advanced codes devoted to forward and inverse spectroscopic retrievals.

In this poster, we present the second generation of the HAPI software (version 2). For this version, most parts of the original HAPI code have been rewritten to enhance running efficiency. Among the prominent features of HAPI v2 are:

1) Fast absorption coefficient calculation using the “just-in-time” (JIT) compiling on CPU and GPU

2) Processing large line lists on clusters using the Message Passing Interface (MPI)

3) HDF5-based storage engine supporting the high-temperature line lists

4) Providing a set of commonly used line profiles and their analytical derivatives with respect to line parameters

5) Set of complex probability functions (CPF) for fast line profile calculations

6) New Web API allowing downloading data and metadata for cross-sections, sources, molecules, collision induced absorption, and individual transitions.

7) Support for the first order (Rosenkranz) line mixing and full line mixing.

8) Providing graphical and command line interfaces.

References:

1. Kochanov R V, Gordon IE, Rothman LS, Wcisło P, Hill C, Wilzewski JS. HITRAN Application Programming Interface (HAPI): a comprehensive approach to working with spectroscopic data. J Quant SpectroscRadiatTransf 177:15–30 (2016). doi:http://dx.doi.org/10.1016/j.jqsrt.2016.03.005.
2. Gordon IE, Rothman LS, Hill C, Kochanov RV, Tan Y, Bernath PF, et al. The HITRAN2016 molecular spectroscopic database. J Quant Spectrosc Radiat Transf, 203:3–69 (2017). doi:10.1016/j.jqsrt.2017.06.038.
3. Hill C, Gordon IE, Kochanov RV, Barrett L, Wilzewski JS, Rothman LS. HITRAN online: An online interface and the flexible representation of spectroscopic data in the HITRAN database. J Quant Spectrosc Radiat Transf, 177:4–14 (2016). doi:10.1016/j.jqsrt.2015.12.012.