What is the Photo Library of Catalonia?

The catalogue of vertical aerial photographs of the Photo Library of Catalonia includes the analogue and digital frames used for the cartographic production of the ICGC and covers from 1942 to the present.

Since its inception, the ICGC has developed a programme for capturing aerial photography using photogrammetric cameras, to satisfy the different image cartography and vector cartography and photogrammetry projects that cover the entire territory at different scales or resolutions.

Apart from the capture of aerial photography by the ICGC for the different services, the Photo Library of Catalonia develops its own programme for the recovery, conservation and preservation of the aerial image collections of our territory, in order to have a complete and exhaustive collection, and makes it available to all users.

The photo library's catalogue currently contains more than 2 million entries, a figure that is constantly growing as digital frames from flights periodically carried out by the Institute are incorporated, and constitutes one of the most relevant assets for the study of the evolution of the territory with the following coverage by decades:

(*) Value as of July 2024 and constantly increasing.

Information collection that makes up the Photo Library of Catalonia 

The sources of aerial image data that the ICGC keeps to build the collections of the Photo Library of Catalonia are diverse:

Own production of the ICGC 

Aerial photographs have been the basis for making maps since the beginning of the Institute's activity. They are 24x24 cm negatives that cover an area of ​​the Earth's surface and have the characteristic of being consecutive images that overlap more than 50% on each other. This superposition called coating is what allows, through photogrammetric restitution, to draw the elements of the map.

Since 1984, the Institute has had its own flight team and annually carries out several photographic campaigns, the result of which constantly increases and updates the archive of the Photo Library. The Institute has had various cameras: 

• 1984. First photogrammetric camera of the ICGC: RC-10 from the Swiss company Wild Heerbrugg. In 1987, the ICGC will acquire a second unit of the RC-10 camera.. 

  Imatge RC10 camera in operation

  Imatge Interior of the ship with photogrammetric flight

• 1991. The RMK-TOP15 camera from the German company Zeiss goes into operation, which is the first camera at the ICGC with FMC (Forward Motion Compensation) to achieve greater stability on the lens at the time of capture and thus obtain sharper images.
• 1992. The RC-30 camera from the Swiss company Wild Heerbrugg goes into operation, which also incorporates FMC technology and replaces the RC-10. The ICGC will acquire a second unit in 1994. 
• 2004. The DMCI goes into operation, the first digital camera at the ICGC with 106 Mpx panchromatic and RGBIr capture from the company Z/Imaging, formed from the collaboration between the companies Intergraph and Zeiss. The ICGC will have two DMCI units until the DMCIII goes into operation.
• 2014. Leica Geosystems' PENTA camera goes into operation, the ICGC's first oblique camera with an 80 Mpx* RDC30 nadiral head and 5 oblique heads. (*) with Bayer filter technology.
• 2017. Leica Geosystems' 375 Mpx Panchromatic DMCIII camera and RGBIr capture goes into operation.
• 2021. Leica Geosystems' TerrainMapper sensor goes into operation, which combines a LiDAR sensor with a 150 Mpx* MFC150 RGBIr nadiral camera. (*) with Bayer filter technology.

The negatives from analog cameras must be scanned with resolution and stability characteristics that allow all the information contained to be collected and minimize distortions. 

Imatge

Observing the fiducial marks at the ends of the frame allows defining an internal reference system for photogrammetric measurements.

Imatge Camera RC-30.  Panchromatic image 1999-09-12

Imatge Camera RC-30. Infrared Image 1997-08-31

Imatge Càmera DMCIII. Imatge digital RGBIr 2023-05-03

Campaigns of old flights of national scope 

There are several historical flights of general coverage over the Spanish State.

• American Flight Series A (1945-1946). Flight scale 1/43,000. Black and white.
  Made by the Army Map Service of the United States.
  The ICGC, through an agreement with the Ministry of Defense, obtains the scanned images to perform their orientation and orthoimage. Available in the different exploitation channels of the Photo Library of Catalonia. 
• American Flight Series B (1956-1957). Flight scale 1/32,000. Black and white.
  Made by the Army Map Service of the United States.
  The ICGC, through an agreement with the intervention of the CNIG, obtains the scanned images to perform their orientation and orthoimage. Available in the different exploitation channels of the Photo Library of Catalonia.
• Flight Series C (1967-1968). Flight scale 1/45,000. Black and white.
  Made by CECAF (Cartographic and Photographic Centre of the Air Force).
• Interministerial Flight (1973-1986). Flight scale 1/18,000. Black and white.
  Coordinated by the Ministry of Agriculture, the Ministry of Public Works and Urban Planning, the Ministry of Finance and the Ministry of Air.
  The ICGC, through an agreement with the CNIG, obtains the scanned images and proceeds to carry out their orientation and orthoimagee.
• National Flight (1980-1986). Flight scale 1/30,000. Black and white. Coordinated by the National Geographic Institute.

The ICGC collaborates with the different institutions that hold the flights in order to have a copy of the scanned negatives to carry out their orientation and thus allow their exploitation through the photo library and the creation of continuous orthoimages that are incorporated into the Territorial Orthophoto programme.

Production of other cartographic services 

The photo library has more than two hundred and fifty thousand vertical photographs in black and white and in colour, which come from the cartographic services transferred to the Generalitat at the beginning of the eighties of the twentieth century, such as those from the Diputació de Barcelona or the Ministry of Public Works (MOPU). The negatives of these analogue frames, as well as analogue negatives from the ICGC's own production, are kept under controlled conditions of temperature and humidity to guarantee their preservation. Also, to guarantee their exploitation without damaging the originals, the ICGC maintains a programme of scanning negatives with high-resolution photogrammetric scanners, which minimise geometric distortions, thus allowing the subsequent production of derivative products such as orthoimages of old flights.

Some of the commercial companies whose flights are preserved are the following:

• AZIMUT.
• AEROFOTO.
• AEROPOST.
• Compañía Española de Trabajos Fotogramétricos Aéreos (CEFTA).
• GEOCART SA.
• Pòlux. Two flights from the province of Girona, carried out with two stops in the 1970s and known as low-flying and high-flying, have been preserved. They have been catalogued but are awaiting digitalisation:
  • GEOFASA.
  • TFA.
  • TASA.

Other panoramic and oblique images

Panoramic and oblique photographs also have a significant role in the information preservation strategy as a testimony to the change of landscape. These photographs are not included in the digital photo library, but are composed of different sources that can be consulted in the Digital Photo Library. Among these funds are the Cuyàs funds, acquired in 1988, with more than two thousand panoramic photographs of Catalonia from the entire 20th century; the SACE fund, acquired in 1996, with more than four thousand oblique aerial photographs of all of Spain, and one hundred oblique aerial photographs of Josep Gaspar from 1929, acquired in 1990. Conservation and digitalization strategy of The negative images of the photogrammetric volumes kept by the ICGC are stored in the archive of the photo library, under special conditions of humidity and temperature to guarantee correct conservation.

Image conservation and digitalization strategy 

The negatives of the photogrammetric volumes kept by the ICGC are also stored in the archive of the photo library, in special conditions of humidity and temperature to guarantee correct conservation.

Imatge

Storage in the photo library archive

Since the late 1990s, the ICGC's analogue production was systematically digitised before entering the different production flows. However, the ICGC's production prior to this systematic scanning and the funds that came from other institutions still constitute a large number of negatives.

Digitisation projects have been evolving since the systematic scanning of the analogue photography collection began. Some of the strategies followed so far have been: 

• Digitising very old flights and on acetate support as a preservation measure. 
• Prioritising wide-coverage flights, as opposed to linear road flights.
• Searching for flights from all periods that allow documenting the transformation of the territory. 
• Collecting the needs of the ICGC to make historical orthophotomaps or viewers. 

In 2019, a systematic digitisation programme was established with the aim of digitising 10,000 negatives/year.

Exploitation and consultation of the photo library of Catalonia

In the Web Photo Library viewer, you can consult more than a million frames of the Catalan territory that are digital or have been digitalized, from 1944 to the present day. It should be noted that in current digital flights, not all the frames of a flight are loaded given the high level of overlap between frames, but a load of frames that completely cover the flight area is guaranteed.

As the digitalization of the analog frames progresses, they will also be available in the Web Photo Library viewer.

The ICGC has more aerial photographs that are still in the process of digitalization or orientation and that will be made available to all users as they become available. However, if you need any photograph from a period that is not available in the Web Photo Library, do not hesitate to contact the ICGC through the Photo Library Service of the User Support Center. You can request them by email and, once they have been located and scanned, they can be purchased at the following rates (prices including VAT):

• DIN-A4 B/W enlargement: 13,55 €.
• DIN-A4 colour enlargement: 15,65 €.
• DIN-A3 B/W enlargement: 22,94 €.
• DIN-A3 colour enlargement: 31,29 €.
• Digital contact (full frame): 14,52 €.

or personalised attention at the ICGC User Assistance Centre (CAU), an appointment must be made in advance by emailing cau@icgc.cat and/or by calling 93 567 15 90.