/* DATA DESCRIPTION: Citation: Khan, Taimur (2026): HeideBench: A Multispectral UAV Time-Series Benchmark for Forest Crown Phenology in Dölauer Heide [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.993969 (DOI registration in progress) Abstract: We present HeideBench, a very-high-resolution multispectral uncrewed aerial vehicle dataset for forest crown phenology collected over a forest patch in Dölauer Heide, Halle (Saale), Germany. Dölauer Heide is currently dominated by pine plantations (Kiefernforste), which cover the largest area but are increasingly affected by dieback, while its potential natural vegetation is sessile oak–hornbeam forest rich in small-leaved lime (Albrecht et al., 1993). In addition to these pine stands, the area contains near-natural mixed deciduous forests with oaks, birches, and beeches, making it a particularly relevant setting for observing seasonal canopy development under contrasting forest structures and ongoing ecological transition. Against this background, HeideBench provides repeated observations of the same forest patch through the growing season. The dataset contains 18 georeferenced multispectral GeoTIFF orthomosaics acquired between 6 March 2025 and 5 November 2025, spanning a 244-day seasonal period from early spring to late autumn. The acquisitions have a median revisit interval of 14 days, with intervals ranging from 4 to 27 days, and an average ground sampling distance of 5.53 cm per pixel. The valid imaging footprint covers approximately 32.1 ha and is bounded by 11.902653–11.911325°E and 51.499959–51.508576°N. Data were collected using a DJI Mavic 3M Enterprise uncrewed aerial vehicle equipped with four multispectral cameras measuring green (560 nm), red (650 nm), red-edge (730 nm), and near-infrared (860 nm) reflectance, in that order. Flights used a real-time kinematic (RTK) positioning module for centimeter-level geolocation, and all data are provided in coordinate reference system EPSG:25832. Imagery was processed with Agisoft Metashape 2.3.1 to generate calibrated multispectral orthomosaics. The dataset further includes 5,885 crop-safe individual tree crown instance segmentations over the same footprint, extracted with the DeepTrees software package (Khan et al., 2025). HeideBench is intended to support crown-centric analyses of seasonal canopy development, temporal representation learning, phenology-aware feature extraction, and the evaluation of tree crown delineation under seasonal change. HeideBench is a result of the Dynamic Platform Project titled "PhenoEmbed: Multispectral UAV AI Embeddings for phenology-aware tree crown delineation" of the Integration Platform 1: "Sustainable future land use" (IP1) at the Helmholz Centre for Environmental Research (UFZ) in Leipzig, Germany. Keyword(s): Forest; Multispectral Image Data; phenology; Timeseries; UAV Related to: Albrecht, T; Buschendorf, J; Drechsler, K; Geissler, H; Gluch, W; Gnielka, R; Weidlich, M (1993): Die Dölauer Heide-Waldidylle in Großstadtnähe. Khan, Taimur; Arnold, Caroline; Grover, Harsh (2025): DeepTrees: Tree Crown Segmentation and Analysis in Remote Sensing Imagery with PyTorch. Journal of Open Source Software, 10(114), 8056, https://doi.org/10.21105/joss.08056 Additional metadata: ReadMe - file description of Multispectral UAV Time-Series Benchmark dataset from Heidebench 2025 (URI: https://download.pangaea.de/reference/139842/attachments/README_v2.md) Coverage: MEDIAN LATITUDE: 51.504267 * MEDIAN LONGITUDE: 11.906989 * SOUTH-BOUND LATITUDE: 51.499959 * WEST-BOUND LONGITUDE: 11.902653 * NORTH-BOUND LATITUDE: 51.508576 * EAST-BOUND LONGITUDE: 11.911325 DATE/TIME START: 2025-03-06T00:00:00 * DATE/TIME END: 2025-11-05T00:00:00 Event(s): HeideBench_2025 (HeideBench) * LATITUDE START: 51.508576 * LONGITUDE START: 11.902653 * LATITUDE END: 51.499959 * LONGITUDE END: 11.911325 * DATE/TIME START: 2025-03-06T00:00:00 * DATE/TIME END: 2025-11-05T00:00:00 * METHOD/DEVICE: Drone, DJI, Mavic3M (URI: https://enterprise.dji.com/mavic-3-m) Parameter(s): Date (Date) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) Raster graphic, GeoTIFF format (GeoTIFF) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) File content (Content) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: file content Coordinate reference system (CRS) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) UTM Easting, Universal Transverse Mercator [m] (UTM east) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: westbound UTM Northing, Universal Transverse Mercator [m] (UTM north) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: southbound UTM Easting, Universal Transverse Mercator [m] (UTM east) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: eastbound UTM Northing, Universal Transverse Mercator [m] (UTM north) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: northbound Longitude, westbound (Longitude west) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: westbound Latitude, southbound (Latitude south) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: southbound Longitude, eastbound (Longitude east) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: eastbound Latitude, northbound (Latitude north) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: northbound Pixel size [m] (Pixel size) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: x-direction Pixel size [m] (Pixel size) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: y-direction Image pixel width [#] (Image pixel w) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) Image pixel height [#] (Image pixel h) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) Comment (Comment) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: Band count Description (Description) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: Band description Feature counts [#] (Feature ctn) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) Date/time start (Date/time start) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: Flight start time (local) Date/time end (Date/time end) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: Flight end time (local) Duration [min] (Duration) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: Flight duration Solar elevation angle [deg] (SEA) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: Min value Solar elevation angle [deg] (SEA) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: Max value Solar azimuth angle [deg] (SAA) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: Min value Solar azimuth angle [deg] (SAA) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: Max value Indicator (Indicator) * PI: Khan, Taimur (https://orcid.org/0000-0001-7833-5474) * COMMENT: Indicator if RTK was used License: Creative Commons Attribution 4.0 International (CC-BY-4.0) (URI: https://creativecommons.org/licenses/by/4.0/) Status: Curation Level: Enhanced curation (URI: https://wiki.pangaea.de/wiki/Curation_levels) Size: 492 data points Files: All files referred to in data matrix can be downloaded in one go as ZIP or TAR (PANGAEA user account required). To download single files, use the filename from data matrix appended to "https://download.pangaea.de/dataset/993969/files/". */ Date GeoTIFF Content (file content) CRS UTM east [m] (westbound) UTM north [m] (southbound) UTM east [m] (eastbound) UTM north [m] (northbound) Longitude west (westbound) Latitude south (southbound) Longitude east (eastbound) Latitude north (northbound) Pixel size [m] (x-direction) Pixel size [m] (y-direction) Image pixel w [#] Image pixel h [#] Comment (Band count) Description (Band description) Feature ctn [#] Date/time start (Flight start time (local)) Date/time end (Flight end time (local)) Duration [min] (Flight duration) SEA [deg] (Min value) SEA [deg] (Max value) SAA [deg] (Min value) SAA [deg] (Max value) Indicator (Indicator if RTK was used) 2025-03-06 20250306.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.514078 5709430.568963 702055.890413 5710392.394042 11.90216371 51.49984313 11.91175570 51.50870472 0.054717549 0.054717549 11484 17578 5 Green|Red|RedEdge|NIR|Alpha 2025-03-06T11:44:00 2025-03-06T12:05:00 21 2845 3088 14889 15852 No 2025-03-18 20250318.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.533271 5709430.563411 702055.868322 5710392.398064 11.90216399 51.49984309 11.91175538 51.50870475 0.056775554 0.056775554 11067 16941 5 Green|Red|RedEdge|NIR|Alpha 2025-03-18T11:42:00 2025-03-18T12:07:00 25 3686 3773 16576 1783 No 2025-04-14 20250414.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.496679 5709430.601957 702055.894581 5710392.390619 11.90216348 51.49984343 11.91175575 51.50870470 0.056363611 0.056363611 11149 17064 5 Green|Red|RedEdge|NIR|Alpha 2025-04-14T11:16:00 2025-04-14T11:37:00 21 4116 4479 13811 15066 Yes 2025-04-28 20250428.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.523166 5709430.560534 702055.860853 5710392.370159 11.90216384 51.49984307 11.91175526 51.50870450 0.054838339 0.054838339 11458 17539 5 Green|Red|RedEdge|NIR|Alpha 2025-04-28T10:27:00 2025-04-28T10:49:00 22 3832 4461 11925 1331 Yes 2025-05-12 20250512.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.501874 5709430.579706 702055.891338 5710392.393546 11.90216354 51.49984323 11.91175571 51.50870472 0.055257603 0.055257603 11372 17406 5 Green|Red|RedEdge|NIR|Alpha 2025-05-12T09:56:00 2025-05-12T10:21:00 25 3812 4441 11035 12186 Yes 2025-05-26 20250526.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.536066 5709430.555442 702055.839805 5710392.388125 11.90216402 51.49984303 11.91175496 51.50870466 0.055284095 0.055284095 11365 17398 5 Green|Red|RedEdge|NIR|Alpha 2025-05-26T10:11:00 2025-05-26T10:33:00 22 4108 494 109 12503 Yes 2025-06-16 20250616.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.506621 5709430.563940 702055.877716 5710392.412189 11.90216360 51.49984309 11.91175552 51.50870489 0.055756086 0.055756086 11270 17251 5 Green|Red|RedEdge|NIR|Alpha 2025-06-16T10:00:00 2025-06-16T10:22:00 22 3292 4211 9302 10597 Yes 2025-06-20 20250620.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.533909 5709430.555979 702055.892695 5710392.372347 11.90216399 51.49984301 11.91175572 51.50870452 0.055080539 0.055080539 11408 17462 5 Green|Red|RedEdge|NIR|Alpha 2025-06-20T09:14:00 2025-06-20T09:36:00 22 3448 391 9507 10145 Yes 2025-06-30 20250630.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.517783 5709430.600372 702055.851401 5710392.385959 11.90216379 51.49984343 11.91175513 51.50870465 0.054943478 0.054943478 11436 17505 5 Green|Red|RedEdge|NIR|Alpha 2025-06-30T09:55:00 2025-06-30T10:22:00 27 4008 474 10345 11575 Yes 2025-07-17 20250717.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.517695 5709430.566922 702055.862595 5710392.400883 11.90216377 51.49984312 11.91175530 51.50870478 0.055507500 0.055507500 11320 17328 5 Green|Red|RedEdge|NIR|Alpha 2025-07-17T09:55:00 2025-07-17T10:20:00 25 3817 4544 10458 11685 Yes 2025-07-29 20250729.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.502187 5709430.593129 702055.885097 5710392.392399 11.90216356 51.49984335 11.91175562 51.50870471 0.055403184 0.055403184 11342 17360 5 Green|Red|RedEdge|NIR|Alpha 2025-07-29T09:24:00 2025-07-29T09:45:00 21 3168 3771 999 10881 Yes 2025-08-12 20250812.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.487115 5709430.566649 702055.880399 5710392.376413 11.90216332 51.49984311 11.91175554 51.50870457 0.054524363 0.054524363 11525 17640 5 Green|Red|RedEdge|NIR|Alpha 2025-08-12T10:22:00 2025-08-12T10:44:00 22 3774 43 1169 12756 Yes 2025-08-25 20250825.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.490691 5709430.564405 702055.864710 5710392.380542 11.90216338 51.49984310 11.91175532 51.50870461 0.055251387 0.055251387 11373 17408 5 Green|Red|RedEdge|NIR|Alpha 2025-08-25T11:40:00 2025-08-25T12:02:00 22 439 4703 14311 15642 Yes 2025-09-08 20250908.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.516066 5709430.554197 702055.869147 5710392.405497 11.90216373 51.49984301 11.91175540 51.50870482 0.054969214 0.054969214 11431 17498 5 Green|Red|RedEdge|NIR|Alpha 2025-09-08T10:57:00 2025-09-08T11:19:00 22 3566 3956 13534 14691 Yes 2025-09-19 20250919.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.536790 5709430.581909 702055.869231 5710392.391153 11.90216405 51.49984325 11.91175539 51.50870469 0.054704200 0.054704200 11486 17582 5 Green|Red|RedEdge|NIR|Alpha 2025-09-19T11:23:00 2025-09-19T11:45:00 22 342 3731 14408 1558 Yes 2025-09-30 20250930.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.538428 5709430.591284 702055.870236 5710392.377940 11.90216408 51.49984334 11.91175540 51.50870457 0.055428000 0.055428000 11336 17352 5 Green|Red|RedEdge|NIR|Alpha 2025-09-30T11:31:00 2025-09-30T11:53:00 22 3135 3393 14967 16113 Yes 2025-10-10 20251010.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.486508 5709430.572308 702055.866365 5710392.382713 11.90216332 51.49984317 11.91175534 51.50870463 0.055130712 0.055130712 11398 17446 5 Green|Red|RedEdge|NIR|Alpha 2025-10-10T12:08:00 2025-10-10T12:30:00 22 3031 3153 16287 17436 Yes 2025-11-05 20251105.tif Georeferenced UAV multispectral GeoTIFF orthomosaic EPSG:25832 701427.499841 5709430.551427 702055.849295 5710392.370942 11.90216350 51.49984299 11.91175509 51.50870452 0.055606146 0.055606146 11300 17297 5 Green|Red|RedEdge|NIR|Alpha 2025-11-05T13:04:00 2025-11-05T13:26:00 22 2233 2274 18104 18884 Yes treecrowns.geojson Merged individual tree crown polygon annotations. EPSG:25832 701431.700000 5709437.700000 702054.100000 5710389.500000 11.90271164 51.50002330 11.91130051 51.50855075 5889 uav_footprint.geojson Valid UAV-imaging footprint polygon. EPSG:25832 701427.483807 5709430.550292 702055.895013 5710392.415008 11.90265314 51.49995902 11.91132465 51.50857579 1