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Frequently Asked Questions - FAQ's

Below are some answers to commonly asked questions about rePhotoSA. If you have any further questions or queries that we do not address below, feel free to contact us here.

Why do I need to register with the ADU?

rePhotoSA is a collaborative project between the Plant Conservation Unit (PCU) and the Animal Demography Unit (ADU). The ADU is has considerable expertise in research involving the voluntary contributions and observations from thousands of citizen scientists, such as bird atlas project SABAP2.

The ADU is providing the support for the website development and online database. They already have a registration procedure in place for other citizen science projects, and rather than 'reinventing' the wheel, we are making use of their experience in this regard.

To register with the ADU and take part in rePhotoSA, click here.

If I am already registered with the ADU for another project do I need to re-register for rePhotoSA?

No, you only need to register once with the ADU.

How can I find and download a photograph from my local area?

We have created a map where you can browse and search for images. The map has been divided into a grid system based on lines of latitude and longitude. Each box or square in the grid system is referred to as a QDS or 'Quarter Degree Square' which is an area roughly 30x30 km in size. If you click on a QDS you will be able to see a list of thumbnails of the original photographs which were taken in that QDS. If you then click on a thumbnail, you will able to view a larger version of the photograph, as well as the metadata associated with that particular image. Options to download the photograph, as well as the metadata, will be available, below the image.

How do I line up my camera with the original image when taking a repeat photograph?

Detailed instructions are available here

Can I take repeat photographs with my smartphone?

Yes, we welcome any digital images. While we prefer images from a digital camera, if you have a good quality camera on your smartphone, you are welcome to upload those images.

What data do I need to collect when I take a repeat photograph?

We have developed a datasheet which you need to download and complete for each photograph that you take. You will need to note data such as the GPS co-ordinates, time of day and weather conditions. This data is important for any future analysis which will take place. However, if you don't have a GPS there is an option, when you upload your repeat photograph, to use Google Maps to pinpoint where you were standing when you took the repeat photograph.

The option to download the datasheet is shown below each photograph. The top section of the datasheet will automatically be completed with the relevant data of the original historical photograph.

Does it matter what time of day or season I take a repeat photograph?

The most important factor in taking a repeat photograph is that you line up the objects in the image. The time of day becomes a factor when there are shadows in the photograph, which can make analysis difficult. If possible, try and estimate the time of day that the original photograph was taken, by looking at the shadows on the photograph. But don't worry if you are unable to match the images by time of day or year.

Seasonality also does play a role in repeat photographs and how they are analysed. But what is most important is that you do take the repeat photograph and submit it to our database and record the GPS coordinates, even if it is not the same season as the original photograph. If necessary, we at the PCU can take a further repeat photograph in the same season as the original was taken.

How do I upload a repeat photograph?

Uploading your repeat photograph is a simple process and can be done in two ways. Either by clicking on the ‘Upload’ tab in the top right hand corner of the website or by using the map to browse to the historical photograph for which you have taken a repeat, and clicking on the ‘upload’ option.

If there is already a repeat photo in the database, should I take another one?

Yes, we are interested in obtaining a time series of photographs of different locations. Although the focus of this project is to try get 'first time' repeat photographs, we still encourage any 'multiple repeats'. These will be useful for detailed analysis of a particular area.

What do I do if I notice an incorrect location description of a photograph (because I recognise an iconic feature in the landscape or it is near my home…)

If this happens, please send us a note and we will do our best to correct the error in future versions of the database.

What do I do if the place I need to get to, to take a repeat photograph, is on private land?

It is very important that you respect the laws of the land in all that you do concerning this project. Please get permission from the relevant land owner before walking on privately-owned or state-owned land. Local municipality staff and agricultural extension officers are important people to contact to find out who owns land in your area of interest.

What is a QDS or 'Quarter Degree Square'?

QDS (quarter-degree-square) or QDGC (quarter-degree-grid-cell) corresponds to the area shown on a 1:50 000 map (15' x 15') and is approximately 27 km long (north-south) and 23 km wide (east-west).

These grid-cells are obtained by drawing lines of latitude and longitude at 15 minutes (15') intervals across a map. This creates a grid of 1/4o squares. It bears mentioning that "quarter degree square" is a misnomer in that there are 16 in a degree square, not four.

If you are working with maps 1:250 000, draw lines with a long ruler and pencil along the 15' intervals, which are clearly marked on the margins. Your map is now divided into QDSs.

Having found your position in a QDS, you need to know the code of that particular square. The code consists of four numbers and two letters (ie 2624BD). The code can be easily worked out using the guide below:

  1. Each degree square is designated by a four-digit number made-up of the values of latitude and longitude at its top left corner, e.g. 3218 (the large square in the diagram below.
  2. Each degree square is divided into sixteen "quarter degree squares", each 15' x 15'. These are given two additional letters as indicated.
  3. In the diagram, the hatched area indicates the QDS 3218CB.

Page served: April 23, 2024, 11:01 +0200