Laser-assisted selection of field plots for an area-based forest inventory
Field measurements conducted on sample plots are a major cost component in airborne laser scanning (ALS) based forest inventories, as field data is needed to obtain reference variables for the statistical models. The ALS data also provides an excellent source of prior information that may be used in...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Finnish Society of Forest Science
2013-01-01
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| Series: | Silva Fennica |
| Online Access: | https://www.silvafennica.fi/article/943 |
| _version_ | 1818380789409120256 |
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| author | Gobakken, Terje Korhonen, Lauri Næsset, Erik |
| author_facet | Gobakken, Terje Korhonen, Lauri Næsset, Erik |
| author_sort | Gobakken, Terje |
| collection | DOAJ |
| description | Field measurements conducted on sample plots are a major cost component in airborne laser scanning (ALS) based forest inventories, as field data is needed to obtain reference variables for the statistical models. The ALS data also provides an excellent source of prior information that may be used in the design phase of the field survey to reduce the size of the field data set. In the current study, we acquired two independent modeling data sets: one with ALS-assisted and another with random plot selection. A third data set was used for validation. One canopy height and one canopy density variable were used as a basis for the ALS-assisted selection. Ordinary and partial least squares regressions for stem volume were fitted for four different strata using the two data sets separately. The results show that the ALS-assisted plot selection helped to decrease the root mean square error (RMSE) of the predicted volume. Although the differences in RMSE were relatively small, models based on random plot selection showed larger mean differences from the reference in the independent validation data. Furthermore, a sub-sampling experiment showed that 40 well placed plots should be enough for fairly reliable predictions. |
| first_indexed | 2024-12-14T02:24:16Z |
| format | Article |
| id | doaj.art-0915639aeaff46f78d7e0ca861e3cb4c |
| institution | Directory Open Access Journal |
| issn | 2242-4075 |
| language | English |
| last_indexed | 2024-12-14T02:24:16Z |
| publishDate | 2013-01-01 |
| publisher | Finnish Society of Forest Science |
| record_format | Article |
| series | Silva Fennica |
| spelling | doaj.art-0915639aeaff46f78d7e0ca861e3cb4c2022-12-21T23:20:25ZengFinnish Society of Forest ScienceSilva Fennica2242-40752013-01-0147510.14214/sf.943Laser-assisted selection of field plots for an area-based forest inventoryGobakken, TerjeKorhonen, LauriNæsset, ErikField measurements conducted on sample plots are a major cost component in airborne laser scanning (ALS) based forest inventories, as field data is needed to obtain reference variables for the statistical models. The ALS data also provides an excellent source of prior information that may be used in the design phase of the field survey to reduce the size of the field data set. In the current study, we acquired two independent modeling data sets: one with ALS-assisted and another with random plot selection. A third data set was used for validation. One canopy height and one canopy density variable were used as a basis for the ALS-assisted selection. Ordinary and partial least squares regressions for stem volume were fitted for four different strata using the two data sets separately. The results show that the ALS-assisted plot selection helped to decrease the root mean square error (RMSE) of the predicted volume. Although the differences in RMSE were relatively small, models based on random plot selection showed larger mean differences from the reference in the independent validation data. Furthermore, a sub-sampling experiment showed that 40 well placed plots should be enough for fairly reliable predictions.https://www.silvafennica.fi/article/943 |
| spellingShingle | Gobakken, Terje Korhonen, Lauri Næsset, Erik Laser-assisted selection of field plots for an area-based forest inventory Silva Fennica |
| title | Laser-assisted selection of field plots for an area-based forest inventory |
| title_full | Laser-assisted selection of field plots for an area-based forest inventory |
| title_fullStr | Laser-assisted selection of field plots for an area-based forest inventory |
| title_full_unstemmed | Laser-assisted selection of field plots for an area-based forest inventory |
| title_short | Laser-assisted selection of field plots for an area-based forest inventory |
| title_sort | laser assisted selection of field plots for an area based forest inventory |
| url | https://www.silvafennica.fi/article/943 |
| work_keys_str_mv | AT gobakkenterje laserassistedselectionoffieldplotsforanareabasedforestinventory AT korhonenlauri laserassistedselectionoffieldplotsforanareabasedforestinventory AT næsseterik laserassistedselectionoffieldplotsforanareabasedforestinventory |