Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4843597 | System for marine seismic exploration | Jens Hjelmstad, Andreas Tonning | 1989-06-27 |
| 4829306 | System for detection of objects with given, known characteristics against a background | Jens Hjelmstad | 1989-05-09 |