Aerial and Terrestrial Thermal Images of German Multi-Family Buildings

This dataset consists of 968 thermal images including 693 captured by hand-held camera on the ground and 275 via UAV. Of the aerial images, 139 were recorded manually and 136 in automatic flight mode. The images depict four multi-family buildings of 18 m height in the German city of Karlsruhe belonging to the local municipal housing association Volkswohnung Karlsruhe GmbH. Table 1 gives an overview of the buildings in question, all of which were fully rented out on the days of image acquisition.

Table 1: Building information

                     Building
Details

Sophienstr. 201-203

Volzstr. 2

Wichernstr. 4

Wichernstr. 10-18

construction year

1957

1954

1953

1953

apartments

30

12

25

30

The aerial images were acquired using DJI’s “Matrice 600” UAV (DJI, 2022) equipped with the “Zenmuse XT2”, a combination of FLIR’s “Duo Pro R” thermal and RGB camera technology and DJI’s gimbal (FLIR, 2021a). All thermal images were recorded in FLIR’s proprietary image format RJPEG. The terrestrial thermographic images were captured with FLIR’s “T200” hand-held camera (FLIR, 2021b) in the standard JPEG format. The emissivity was set to 0.95 throughout the acquisition of both aerial and terrestrial images. Thermographic image processing and analysis was realized using the "FLIR Thermal Studio" software (FLIR Systems Inc., 2022). The temperature scale was set to -8 °C to +13 °C and color distribution function "signal linear" selected.

The thermal images of this dataset were recorded on February 28th and March 1st, 2022, between 8 p.m. and 1 a.m. On February 28th the outside air temperature registered at between 1 °C and 3 °C. Wind speeds reached a maximum of 17 km/h. The sky was cloudless both during the flights and in the preceding 24 hours. A maximum temperature of 11 °C was recorded by local weather stations in that time period. Very similar weather conditions were present on March 1st. The outside air temperature was recorded at between -1 °C and 5 °C during acquisition, with wind speeds of max. 11 km/h. Again, the sky was entirely clear both during the flights and in the preceding 24 hours, with a maximum temperature of 9 °C present in that time period. The sun set at around 6:10 p.m. on both days (timeanddate, 2022).

The images were recorded using ten different flight settings of varying speed, flight height, and camera angle. Details are summarized in Table 2.

Table 2: Flight settings

Flight

Building

Automatically/ manually performed flight route

Camera angle

[°]

Height above ground

[m]

Height above building

[m]

Distance to façade

[m]

Flight speed

[m/s]

1

Full area

Automatically

45 (oblique)

40

22

-

1

2

Full area

Automatically

45 (oblique)

40

22

-

3

3

Full area

Automatically

45 (oblique)

40

22

-

5

4

Full area

Automatically

45 (oblique)

60

42

-

3

5

Full area

Automatically

90 (nadir)

40

22

-

3

6

Full area

Automatically

90 (nadir)

60

42

-

3

7

Wichernstr. 4

Manually

0 (manual)

4 to 12

-

4

-

8

Wichernstr. 4

Manually

0 (manual)

4 to 12

-

8

-

9

Wichernstr. 4

Manually

0 (manual)

4 to 12

-

15

-

10

Wichernstr. 10-18

Manually

0 (manual)

4 to 12

-

15

-

Acknowledgments: The authors appreciate the support of Marinus Vogl (Air Bavarian GmbH) in acquiring the thermal images via UAV. Moreover, they thank Harald Schneider (Karlsruhe Institute of Technology) for his advice and assistance. Lastly, they gratefully acknowledge the consent and support of Karlsruher Volkswohnung GmbH within this research project.

References:

DJI (2022).  Matrice 600 - DJI. URL: https://www.dji.com/de/matrice600 (accessed 10th January 2022)

FLIR (2021a).  FLIR XT2 product information (Wilsonville, USA). URL: https://www.flir.de/products/xt2/ (accessed 10th January 2022)

FLIR (2021b).  FLIR T-series (Wilsonville, USA). URL: https://www.flir.com/instruments/t-series/  (accessed 10th January 2022)

FLIR Systems Inc. (2022). User’s manual Flir Thermal Studio. URL: https://www.sahkonumerot.fi/6708162/doc/operatinginstructions/ (accessed 12th August 2022)

Timeanddate (2022). Wetter im Februar 2022 in Karlsruhe, Baden-Württemberg, Deutschland. URL: https://www.timeanddate.de/wetter/deutschland/karlsruhe/rueckblick?month=2&year=2022  (accessed 12th March 2022)