GeoTiles.nl

Map - Town index - Tile index


Relevant towns and neighbourhoods

Stede Broec (woonkern)Grootebroek (deelkern)Hoogkarspel (woonkern)Venhuizen (woonkern)Hem (woonkern)Bovenkarspel (deelkern)Lutjebroek (deelkern)

Tile 20AN1

Actueel Hoogtebestand Nederland

Point cloud

The aerial photograph closest to the acquisition date of the AHN iteration was overlaid on the point cloud to produce a colored version for visualisation purposes. Furthermore, for each point cloud a spatial index and textual summary, including elevation histogram, are provided. Please note that the images are not from the same flight, and may be years off. Therefore, small alignment errors and differences occur between them.

Zoom in on the map to see tiled versions (25 tiles of 1×1.25 km). Tiled versions typically fit into memory (RAM) are easier to handle and are especially suitable for parallel processing and Machine Learning.

Version Point cloud Spatial index Info License
AHN1 Ground 20an1.laz.zip 9.8 MiB1 20an1.lax 18 kiB 20an1.txt 9 kiB Stuurgroep AHN, public domain
Non-ground 20an1.laz.zip 545 kiB1 20an1.lax 63 kiB 20an1.txt 9 kiB Stuurgroep AHN, public domain
Merged 20AN1.LAZ 10.3 MiB 20AN1.LAX 21 kiB 20AN1.txt 9 kiB Stuurgroep AHN (merged product by GeoTiles.nl)
Colored Available for sub-units only, zoom in to select. Remixed by GeoTiles.nl
AHN2 Ground g20an1.laz.zip 300.2 MiB1 g20an1.lax 115 kiB g20an1.txt 4 kiB Stuurgroep AHN, public domain
Non-ground u20an1.laz.zip 200.0 MiB1 u20an1.lax 102 kiB u20an1.txt 16 kiB Stuurgroep AHN, public domain
Merged 20AN1.LAZ 500.2 MiB 20AN1.LAX 586 kiB 20AN1.txt 16 kiB Stuurgroep AHN (merged product by GeoTiles.nl)
Colored Available for sub-units only, zoom in to select. Remixed by GeoTiles.nl
AHN3 Original C_20AN1.LAZ 1.7 GiB C_20AN1.LAX 1.9 MiB C_20AN1.txt 16 kiB Stuurgroep AHN, public domain
Colored Available for sub-units only, zoom in to select. Remixed by GeoTiles.nl
AHN4 Original C_20AN1.LAZ 4.6 GiB C_20AN1.LAX 2.0 MiB C_20AN1.txt 18 kiB Het Waterschapshuis, public domain
Colored (Partially) available for sub-units. Remixed by GeoTiles.nl

1Size of the .laz file, contained in the archive.

2The point cloud is in the public domain and the aerial photograph available under CC-BY. However, the colored point cloud is a new product created by GeoTiles.nl.

File checksums (md5) are available for AHN1, AHN2 and AHN3.

Raster

Version DSM DTM ('maaiveld') License
5 meter ½ meter 5 meter ½ meter
AHN1 20an1.tif.zip public domain
AHN2 r20an1.tif.zip ahn2_5_20an1.tif.zip i20an1.tif.zip public domain *
AHN3 R5_20AN1.ZIP R_20AN1.ZIP M5_20AN1.ZIP M_20AN1.ZIP CC-0
AHN4 R5_20AN1.zip R_20AN1.zip M5_20AN1.zip M_20AN1.zip CC-0 [1, 2, 3, 4]

InSAR

Orbit CSV License
Ascending, 015
Ascending, 088 20AN1.csv.xz 17.1 MiB 20AN1.csv Rijkswaterstaat, CC-0
Ascending, 161 20AN1.csv.xz 19.2 MiB 20AN1.csv Rijkswaterstaat, CC-0
Descending, 037 20AN1.csv.xz 20.0 MiB 20AN1.csv Rijkswaterstaat, CC-0
Descending, 110 20AN1.csv.xz 18.6 MiB 20AN1.csv Rijkswaterstaat, CC-0
Descending, 139

Official documentation is only available in Dutch. Malformed rows, that do not adhere to the format as specified in the documentation, were removed from the data.

Data is compressed with xz-compression. Tools like Pandas are able to read those files transparently. Users of other tools may wish to decompress the files first. Windows users may use 7-Zip, Linux users are likely to have the unxz command available on their machine already.Uncompressed, equivalent, archives are hosted by Rijkswaterstaat.

Aerial photograph

Year Version GeoTiff Source License
2016 RGB RGB_20AN1.tiff 71.3 MiB Beeldmateriaal, nlextract.nl CC-BY 4.0
CIR CIR_20AN1.tiff 67.6 MiB CC-BY 4.0
2017 RGB RGB_20AN1.tiff 56.7 MiB Beeldmateriaal, nlextract.nl CC-BY 4.0
CIR CIR_20AN1.tiff 54.5 MiB CC-BY 4.0
2018 RGB RGB_20AN1.tiff 66.5 MiB Beeldmateriaal, nlextract.nl CC-BY 4.0
CIR CIR_20AN1.tiff 66.6 MiB CC-BY 4.0
2019 RGB RGB_20AN1.tiff 58.2 MiB Beeldmateriaal CC-BY 4.0
CIR CIR_20AN1.tiff 55.1 MiB CC-BY 4.0
2020 RGB RGB_20AN1.tiff 54.7 MiB Beeldmateriaal CC-BY 4.0
CIR CIR_20AN1.tiff 52.5 MiB CC-BY 4.0

Sub-tiles 20AN1

Image adapted from OpenTopo.

Actueel Hoogtebestand Nederland

Point cloud

These sub-tiles of 1×1.25 km are clipped from the original point cloud. Goal is to enable distributed processing of the point cloud. Therefore, a 25 m overlap to the neighbouring (sub-)tiles is added. Thanks to the overlap between sub-tiles, the sub-tiles can be processed independently and therefore parallel.

All other data sets on this website are only available in the main tiling schema.

Tile Version Point cloud Spatial index Info Residential areas License
20AN1_01 AHN1 20AN1_01.LAZ 835 kiB 20AN1_01.LAX 4 kiB 20AN1_01.txt 8 kiB AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_01.LAZ 45.8 MiB 20AN1_01.LAX 28 kiB 20AN1_01.txt 10 kiB
AHN3 20AN1_01.LAZ 106.3 MiB 20AN1_01.LAX 87 kiB 20AN1_01.txt 11 kiB
AHN4 20AN1_01.LAZ 219.6 MiB 20AN1_01.LAX 100 kiB 20AN1_01.txt 13 kiB
20AN1_02 AHN1 20AN1_02.LAZ 829 kiB 20AN1_02.LAX 4 kiB 20AN1_02.txt 9 kiB AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_02.LAZ 42.1 MiB 20AN1_02.LAX 24 kiB 20AN1_02.txt 11 kiB
AHN3 20AN1_02.LAZ 112.9 MiB 20AN1_02.LAX 88 kiB 20AN1_02.txt 12 kiB
AHN4 20AN1_02.LAZ 207.2 MiB 20AN1_02.LAX 98 kiB 20AN1_02.txt 14 kiB
20AN1_03 AHN1 20AN1_03.LAZ 849 kiB 20AN1_03.LAX 4 kiB 20AN1_03.txt 8 kiB Stede Broec, Lutjebroek, Grootebroek AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_03.LAZ 46.2 MiB 20AN1_03.LAX 25 kiB 20AN1_03.txt 10 kiB
AHN3 20AN1_03.LAZ 117.8 MiB 20AN1_03.LAX 89 kiB 20AN1_03.txt 11 kiB
AHN4 20AN1_03.LAZ 213.6 MiB 20AN1_03.LAX 97 kiB 20AN1_03.txt 13 kiB
20AN1_04 AHN1 20AN1_04.LAZ 902 kiB 20AN1_04.LAX 4 kiB 20AN1_04.txt 9 kiB Stede Broec, Grootebroek, Lutjebroek AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_04.LAZ 43.3 MiB 20AN1_04.LAX 24 kiB 20AN1_04.txt 11 kiB
AHN3 20AN1_04.LAZ 104.5 MiB 20AN1_04.LAX 88 kiB 20AN1_04.txt 11 kiB
AHN4 20AN1_04.LAZ 198.6 MiB 20AN1_04.LAX 99 kiB 20AN1_04.txt 14 kiB
20AN1_05 AHN1 20AN1_05.LAZ 878 kiB 20AN1_05.LAX 4 kiB 20AN1_05.txt 8 kiB Stede Broec, Bovenkarspel, Grootebroek AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_05.LAZ 46.2 MiB 20AN1_05.LAX 26 kiB 20AN1_05.txt 11 kiB
AHN3 20AN1_05.LAZ 109.5 MiB 20AN1_05.LAX 92 kiB 20AN1_05.txt 12 kiB
AHN4 20AN1_05.LAZ 214.0 MiB 20AN1_05.LAX 100 kiB 20AN1_05.txt 14 kiB
20AN1_06 AHN1 20AN1_06.LAZ 1.0 MiB 20AN1_06.LAX 3 kiB 20AN1_06.txt 10 kiB Hoogkarspel AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_06.LAZ 64.6 MiB 20AN1_06.LAX 29 kiB 20AN1_06.txt 16 kiB
AHN3 20AN1_06.LAZ 117.1 MiB 20AN1_06.LAX 88 kiB 20AN1_06.txt 15 kiB
AHN4 20AN1_06.LAZ 250.3 MiB 20AN1_06.LAX 100 kiB 20AN1_06.txt 19 kiB
20AN1_07 AHN1 20AN1_07.LAZ 1.0 MiB 20AN1_07.LAX 4 kiB 20AN1_07.txt 10 kiB Hoogkarspel, Stede Broec, Lutjebroek AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_07.LAZ 58.9 MiB 20AN1_07.LAX 26 kiB 20AN1_07.txt 13 kiB
AHN3 20AN1_07.LAZ 118.5 MiB 20AN1_07.LAX 91 kiB 20AN1_07.txt 13 kiB
AHN4 20AN1_07.LAZ 252.5 MiB 20AN1_07.LAX 100 kiB 20AN1_07.txt 15 kiB
20AN1_08 AHN1 20AN1_08.LAZ 951 kiB 20AN1_08.LAX 4 kiB 20AN1_08.txt 9 kiB Stede Broec, Lutjebroek, Grootebroek AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_08.LAZ 51.3 MiB 20AN1_08.LAX 24 kiB 20AN1_08.txt 14 kiB
AHN3 20AN1_08.LAZ 108.9 MiB 20AN1_08.LAX 86 kiB 20AN1_08.txt 17 kiB
AHN4 20AN1_08.LAZ 230.9 MiB 20AN1_08.LAX 100 kiB 20AN1_08.txt 19 kiB
20AN1_09 AHN1 20AN1_09.LAZ 983 kiB 20AN1_09.LAX 4 kiB 20AN1_09.txt 9 kiB Stede Broec, Grootebroek, Lutjebroek AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_09.LAZ 58.6 MiB 20AN1_09.LAX 28 kiB 20AN1_09.txt 17 kiB
AHN3 20AN1_09.LAZ 117.4 MiB 20AN1_09.LAX 94 kiB 20AN1_09.txt 17 kiB
AHN4 20AN1_09.LAZ 262.9 MiB 20AN1_09.LAX 100 kiB 20AN1_09.txt 19 kiB
20AN1_10 AHN1 20AN1_10.LAZ 994 kiB 20AN1_10.LAX 3 kiB 20AN1_10.txt 10 kiB Stede Broec, Grootebroek, Bovenkarspel AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_10.LAZ 64.1 MiB 20AN1_10.LAX 28 kiB 20AN1_10.txt 14 kiB
AHN3 20AN1_10.LAZ 123.8 MiB 20AN1_10.LAX 95 kiB 20AN1_10.txt 16 kiB
AHN4 20AN1_10.LAZ 265.9 MiB 20AN1_10.LAX 100 kiB 20AN1_10.txt 17 kiB
20AN1_11 AHN1 20AN1_11.LAZ 959 kiB 20AN1_11.LAX 4 kiB 20AN1_11.txt 8 kiB Hoogkarspel AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_11.LAZ 75.4 MiB 20AN1_11.LAX 41 kiB 20AN1_11.txt 12 kiB
AHN3 20AN1_11.LAZ 113.7 MiB 20AN1_11.LAX 87 kiB 20AN1_11.txt 13 kiB
AHN4 20AN1_11.LAZ 223.9 MiB 20AN1_11.LAX 99 kiB 20AN1_11.txt 15 kiB
20AN1_12 AHN1 20AN1_12.LAZ 915 kiB 20AN1_12.LAX 4 kiB 20AN1_12.txt 8 kiB Hoogkarspel AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_12.LAZ 42.9 MiB 20AN1_12.LAX 25 kiB 20AN1_12.txt 11 kiB
AHN3 20AN1_12.LAZ 98.8 MiB 20AN1_12.LAX 90 kiB 20AN1_12.txt 11 kiB
AHN4 20AN1_12.LAZ 193.3 MiB 20AN1_12.LAX 100 kiB 20AN1_12.txt 13 kiB
20AN1_13 AHN1 20AN1_13.LAZ 862 kiB 20AN1_13.LAX 4 kiB 20AN1_13.txt 8 kiB AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_13.LAZ 39.5 MiB 20AN1_13.LAX 22 kiB 20AN1_13.txt 10 kiB
AHN3 20AN1_13.LAZ 91.6 MiB 20AN1_13.LAX 85 kiB 20AN1_13.txt 10 kiB
AHN4 20AN1_13.LAZ 191.9 MiB 20AN1_13.LAX 100 kiB 20AN1_13.txt 12 kiB
20AN1_14 AHN1 20AN1_14.LAZ 919 kiB 20AN1_14.LAX 4 kiB 20AN1_14.txt 9 kiB Grootebroek, Stede Broec, Venhuizen AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_14.LAZ 45.3 MiB 20AN1_14.LAX 24 kiB 20AN1_14.txt 11 kiB
AHN3 20AN1_14.LAZ 99.7 MiB 20AN1_14.LAX 81 kiB 20AN1_14.txt 12 kiB
AHN4 20AN1_14.LAZ 205.7 MiB 20AN1_14.LAX 100 kiB 20AN1_14.txt 16 kiB
20AN1_15 AHN1 20AN1_15.LAZ 975 kiB 20AN1_15.LAX 4 kiB 20AN1_15.txt 10 kiB Stede Broec, Grootebroek, Bovenkarspel, Venhuizen AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_15.LAZ 60.1 MiB 20AN1_15.LAX 28 kiB 20AN1_15.txt 12 kiB
AHN3 20AN1_15.LAZ 108.3 MiB 20AN1_15.LAX 85 kiB 20AN1_15.txt 13 kiB
AHN4 20AN1_15.LAZ 266.9 MiB 20AN1_15.LAX 100 kiB 20AN1_15.txt 15 kiB
20AN1_16 AHN1 20AN1_16.LAZ 828 kiB 20AN1_16.LAX 4 kiB 20AN1_16.txt 9 kiB AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_16.LAZ 39.0 MiB 20AN1_16.LAX 20 kiB 20AN1_16.txt 11 kiB
AHN3 20AN1_16.LAZ 93.8 MiB 20AN1_16.LAX 81 kiB 20AN1_16.txt 12 kiB
AHN4 20AN1_16.LAZ 230.1 MiB 20AN1_16.LAX 100 kiB 20AN1_16.txt 14 kiB
20AN1_17 AHN1 20AN1_17.LAZ 791 kiB 20AN1_17.LAX 4 kiB 20AN1_17.txt 9 kiB AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_17.LAZ 52.9 MiB 20AN1_17.LAX 32 kiB 20AN1_17.txt 13 kiB
AHN3 20AN1_17.LAZ 96.6 MiB 20AN1_17.LAX 81 kiB 20AN1_17.txt 13 kiB
AHN4 20AN1_17.LAZ 239.2 MiB 20AN1_17.LAX 100 kiB 20AN1_17.txt 17 kiB
20AN1_18 AHN1 20AN1_18.LAZ 840 kiB 20AN1_18.LAX 4 kiB 20AN1_18.txt 9 kiB Venhuizen AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_18.LAZ 53.9 MiB 20AN1_18.LAX 31 kiB 20AN1_18.txt 12 kiB
AHN3 20AN1_18.LAZ 94.2 MiB 20AN1_18.LAX 80 kiB 20AN1_18.txt 12 kiB
AHN4 20AN1_18.LAZ 228.5 MiB 20AN1_18.LAX 100 kiB 20AN1_18.txt 13 kiB
20AN1_19 AHN1 20AN1_19.LAZ 870 kiB 20AN1_19.LAX 4 kiB 20AN1_19.txt 10 kiB Venhuizen AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_19.LAZ 62.3 MiB 20AN1_19.LAX 33 kiB 20AN1_19.txt 12 kiB
AHN3 20AN1_19.LAZ 104.7 MiB 20AN1_19.LAX 86 kiB 20AN1_19.txt 13 kiB
AHN4 20AN1_19.LAZ 251.2 MiB 20AN1_19.LAX 100 kiB 20AN1_19.txt 16 kiB
20AN1_20 AHN1 20AN1_20.LAZ 847 kiB 20AN1_20.LAX 4 kiB 20AN1_20.txt 9 kiB Venhuizen AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_20.LAZ 60.2 MiB 20AN1_20.LAX 31 kiB 20AN1_20.txt 12 kiB
AHN3 20AN1_20.LAZ 113.2 MiB 20AN1_20.LAX 87 kiB 20AN1_20.txt 13 kiB
AHN4 20AN1_20.LAZ 252.5 MiB 20AN1_20.LAX 99 kiB 20AN1_20.txt 15 kiB
20AN1_21 AHN1 20AN1_21.LAZ 857 kiB 20AN1_21.LAX 4 kiB 20AN1_21.txt 9 kiB Hem AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_21.LAZ 49.4 MiB 20AN1_21.LAX 28 kiB 20AN1_21.txt 11 kiB
AHN3 20AN1_21.LAZ 110.9 MiB 20AN1_21.LAX 92 kiB 20AN1_21.txt 11 kiB
AHN4 20AN1_21.LAZ 398.0 MiB 20AN1_21.LAX 100 kiB 20AN1_21.txt 13 kiB
20AN1_22 AHN1 20AN1_22.LAZ 885 kiB 20AN1_22.LAX 4 kiB 20AN1_22.txt 10 kiB Hem AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_22.LAZ 52.6 MiB 20AN1_22.LAX 29 kiB 20AN1_22.txt 14 kiB
AHN3 20AN1_22.LAZ 116.5 MiB 20AN1_22.LAX 94 kiB 20AN1_22.txt 15 kiB
AHN4 20AN1_22.LAZ 423.1 MiB 20AN1_22.LAX 100 kiB 20AN1_22.txt 17 kiB
20AN1_23 AHN1 20AN1_23.LAZ 892 kiB 20AN1_23.LAX 4 kiB 20AN1_23.txt 9 kiB Venhuizen, Hem AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_23.LAZ 54.0 MiB 20AN1_23.LAX 28 kiB 20AN1_23.txt 12 kiB
AHN3 20AN1_23.LAZ 119.4 MiB 20AN1_23.LAX 87 kiB 20AN1_23.txt 12 kiB
AHN4 20AN1_23.LAZ 330.7 MiB 20AN1_23.LAX 100 kiB 20AN1_23.txt 14 kiB
20AN1_24 AHN1 20AN1_24.LAZ 840 kiB 20AN1_24.LAX 3 kiB 20AN1_24.txt 8 kiB Venhuizen AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_24.LAZ 47.5 MiB 20AN1_24.LAX 28 kiB 20AN1_24.txt 11 kiB
AHN3 20AN1_24.LAZ 102.2 MiB 20AN1_24.LAX 84 kiB 20AN1_24.txt 13 kiB
AHN4 20AN1_24.LAZ 227.0 MiB 20AN1_24.LAX 100 kiB 20AN1_24.txt 15 kiB
20AN1_25 AHN1 20AN1_25.LAZ 697 kiB 20AN1_25.LAX 3 kiB 20AN1_25.txt 8 kiB AHN (stuurgroep AHN, public data) and aerial photograph (Beeldmateriaal, CC-BY) remixed by GeoTiles.nl, CC-BY
AHN2 20AN1_25.LAZ 33.8 MiB 20AN1_25.LAX 19 kiB 20AN1_25.txt 9 kiB
AHN3 20AN1_25.LAZ 73.4 MiB 20AN1_25.LAX 64 kiB 20AN1_25.txt 10 kiB
AHN4 20AN1_25.LAZ 174.7 MiB 20AN1_25.LAX 92 kiB 20AN1_25.txt 13 kiB

At the boundaries of its current availability, AHN4 is complemented with AHN3 to ensure full coverage.


No guarantee on availability, completeness, correctness or fitness for any particular purpose is implied by the distribution of or linking to this data. The license indicated with the products is to the best of my knowledge at the time of writing. Please confirm the applicable license with the source before integrating the data.