Imagery and Intelligence Collection
Lands Department who plays the vital role in collection of imagery and intelligence, is responsible for the provision of:
- Aerial Survey Services;
- Photogrammetric Survey and Remote Sensing Services; and
- Change Detection Services.
Aerial Survey
Lands Department provides aerial survey services for the acquisition and reproduction of aerial photographs. Aerial photographs captured at various flying heights over different years covering the whole territory of Hong Kong are being used for map updating, emergency survey, evidence gathering, planning, prediction and change detection purposes. Aerial photographs may also be adopted pursuant to the relevant Ordinances including Town Planning Ordinance (Cap.131) and Residential Properties (First-hand Sales) Ordinance (Cap.621).
![Aerial Survey 1 Aerial Survey 1](/images/en/spatial-data/imagery-intelligence-collection/aerial-survey_1.jpg)
![Aerial Survey 2 Aerial Survey 2](/images/en/spatial-data/imagery-intelligence-collection/aerial-survey_2.jpg)
- Free download of aerial photographs
- More details about aerial photographs and Digital Aerial Photo (DAP)
The Lands Department has been undertaking aerial surveys by Unmanned Aerial Vehicle (UAV) since 2013 as a quicker and more cost-effective means for the acquisition of aerial survey data. UAV surveys allow for the rapid collection of high-quality data at localized sites, or capture an entire landscape. It is used to supplement the manned aircraft aerial operations for the purposes of basic map updating, 3D model creation, emergency survey and so on within government.
![Unmanned Aerial Vehicle Survey Unmanned Aerial Vehicle Survey](/images/en/spatial-data/imagery-intelligence-collection/unmanned-aerial-vehicle-survey.jpg)
Photogrammetric Survey and Remote Sensing
Lands Department provides the photogrammetric survey and remote sensing services to facilitate land administration, map updating and production of Digital Orthophoto and Orthophoto Map.
![Photogrammetric Survey Photogrammetric Survey](/images/en/spatial-data/imagery-intelligence-collection/photogrammetric-survey.jpg)
- More details about Digital Orthophoto
Change Detection
Lands Department provides the change detection services to support squatter control, land control and lease enforcement activities, as well as the daily operations of other Government Bureaux/Departments (B/Ds). Concerned changes are identified from imagery data such as satellite images, Digital Aerial Photos and images captured by UAVs.
![Image Captured during Epoch 1 Image Captured during Epoch 1](/images/en/spatial-data/imagery-intelligence-collection/image-epoch_1.png)
![Image Captured during Epoch 2 Image Captured during Epoch 2](/images/en/spatial-data/imagery-intelligence-collection/image-epoch_2.png)
![Changes between Two Epochs Changes between Two Epochs](/images/en/spatial-data/imagery-intelligence-collection/image-change.png)