From 14 – 25 August 2010, scientists from around the world are gathering in Southern Turkey to measure the spectral reflectance of a few square kilometres of salt. These measurements will have a major impact on the future of satellite based Earth observation, and will ultimately improve our understanding of the Earth’s climate.
For ten months of the year Tuz Golu (Lake Tuz) in southern Turkey appears to be like any other lake. However, during July and August it dries to become a bright, pristine, white surface, which is ideal for calibrating Earth observation satellites.
Tuz Golu is one of eight sites recently endorsed by the Committee on Earth Observation Satellites (CEOS) to become an international reference standard to evaluate satellites’ sensor-to-sensor biases, and also to calibrate/validate their radiometric performance…
Routine measurements for agriculture, resource and disaster monitoring rely on linking data from different satellites to ensure continuous time coverage, seeking to realise the vision of a Global Earth Observing System of Systems – GEOSS…
Whilst the scientists make ground-based measurements at Tuz Golu, a range of satellites will simultaneously measure the same site. This allows the satellites’ performances to be evaluated.
This comparison marks the first step towards establishing an operational calibration service for Earth observation sensors. The long-term goal is to automate and link the measurements of the eight reference sites as a network (LandNET), and then to tailor signals to match the different response and geometric conditions of different sensors.
Many folks who’ve never worked in science or engineering don’t realize the important of standards, the accuracy of standards. They figure the length of a foot from a yardstick is good enough – and if all you’re building is a tripod for bean runners in your garden, perfectly acceptable.
To gauge the usefulness of data – especially that gathered from distance as from the sensors in a satellite – accuracy of an agreed-upon standard is prime. Checking and re-checking that accuracy helps to guarantee productive results.