{"id":26163670,"url":"https://github.com/maltegrosse/go-spa","last_synced_at":"2026-04-22T06:44:58.949Z","repository":{"id":109063006,"uuid":"263138448","full_name":"maltegrosse/go-spa","owner":"maltegrosse","description":"Go adoption of NREL's Solar Position Algorithm (SPA), which calculates the solar zenith and azimuth angles in the period from the year -2000 to 6000","archived":false,"fork":false,"pushed_at":"2020-05-11T19:34:11.000Z","size":16,"stargazers_count":1,"open_issues_count":0,"forks_count":0,"subscribers_count":1,"default_branch":"master","last_synced_at":"2025-03-11T14:48:38.099Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":"","language":"Go","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"other","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/maltegrosse.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2020-05-11T19:30:25.000Z","updated_at":"2022-09-25T13:25:18.000Z","dependencies_parsed_at":"2023-04-08T08:05:38.000Z","dependency_job_id":null,"html_url":"https://github.com/maltegrosse/go-spa","commit_stats":null,"previous_names":[],"tags_count":1,"template":false,"template_full_name":null,"purl":"pkg:github/maltegrosse/go-spa","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/maltegrosse%2Fgo-spa","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/maltegrosse%2Fgo-spa/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/maltegrosse%2Fgo-spa/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/maltegrosse%2Fgo-spa/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/maltegrosse","download_url":"https://codeload.github.com/maltegrosse/go-spa/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/maltegrosse%2Fgo-spa/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":28021559,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","status":"online","status_checked_at":"2025-12-25T02:00:05.988Z","response_time":58,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2025-03-11T14:38:47.971Z","updated_at":"2025-12-25T06:01:30.906Z","avatar_url":"https://github.com/maltegrosse.png","language":"Go","funding_links":[],"categories":[],"sub_categories":[],"readme":"Go-Solar Position Algorithm (SPA)\n=======================================\n[![Go Report Card](https://goreportcard.com/badge/github.com/maltegrosse/go-spa)](https://goreportcard.com/report/github.com/maltegrosse/go-spa)\n[![GoDoc](https://godoc.org/github.com/maltegrosse/go-spa?status.svg)](https://pkg.go.dev/github.com/maltegrosse/go-spa)\n![Go](https://github.com/maltegrosse/go-spa/workflows/Go/badge.svg) \n\nNREL's Solar Position Algorithm (SPA) calculates the solar zenith and azimuth angles in the period from the year -2000 to 6000, with uncertainties of +/- 0.0003 degrees based on the date, time, and location on Earth. \n\n(Reference: Reda, I.; Andreas, A., Solar Position Algorithm for Solar Radiation Applications, Solar Energy. Vol. 76(5), 2004; pp. 577-589). \n## Installation\n\nThis packages requires Go 1.13. If you installed it and set up your GOPATH, just run:\n\n`go get -u github.com/maltegrosse/go-spa`\n\n## Usage\n\nYou can find some examples in the [examples](examples) directory.\n\nPlease visit https://midcdmz.nrel.gov/spa/ for additional information.\n\nSome additional helper functions have been added to the original application logic.\n## Notes\n\n\n|       | NREL spa_tester.c   | SPA GO    |  \n|---------------|-------|-------|\n| Julian Day     | 2452930.312847  | 2452930.312847  | \n| L          | 24.01826  | 24.018262  | \n| B      | -0.0001011219  | -0.000101121925  | \n| R            |  0.996542  | 0.996542  | \n| H  |  11.105902  |  11.105902  | \n| Delta Psi          | -0.003998404  | -0.003998404303  | \n| Delta Epsilon         | 0.001666568  | 0.001666568177  | \n| Epsilon          | 23.440465 | 23.440465  | \n| Zenith     | 50.111622 | 50.111622 | \n| Azimuth     | 194.340241  | 194.340241 | \n| Incidence      | 25.187000  | 25.187000  | \n| Sunrise         | 2003-10-17 06:12:43  | 2003-10-17 06:12:43 | \n| Sunset           | 2003-10-17 17:20:19  | 2003-10-17 17:20:19 |\n\n\n\n## License\n**[NREL SPA License](https://midcdmz.nrel.gov/spa/#license)**\n\nAdoption in Golang under **[MIT license](http://opensource.org/licenses/mit-license.php)** 2020 © Malte Grosse.\n\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmaltegrosse%2Fgo-spa","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fmaltegrosse%2Fgo-spa","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmaltegrosse%2Fgo-spa/lists"}