Satellite derived products vs in-situ snow depth data

In these comparisons, FSC (SCE) and binary snow cover values from satellite products are compared with SD values from in-situ measurements, which are available through FMI open data.

After collecting all data pairs, binary snow cover information (snow covered or snow free) is determined from FSC values by using FSC and SD thresholds. If the product already provides binary snow cover information, class values are converted to 0 and 100 before the thresholding. These thresholds can be changed from the "Comparison options" menu. Invalid values (nan, cloud, dark etc.) are discarded. 'N days' in maps corresponds to the number of days which has valid data for each location.

Accuracy Maps show accuracy values calculated using data pairs for each location in contingency tables. Accuracy from 0% to 100% is colored from red to green. False Alarm Rate Maps show false alarm rate values calculated using data pairs for each location in contingency tables. False alarm rates from 0% to 100% is colored green to red. If FAR cannot be calculated, the data location is shown in white color.

Maps and plots will only be visible if there is any valid data in comparison. For example, there may be no valid data in winter days due to the camera data corresponds to the low sun zenith angle (polar night) pixels.

From the listed products, "EUMETSAT HSAF H34" and "EUMETSAT HSAF H43" are binary snow cover products, i.e. only 0% and 100% values are presented in the comparison. Please consider that when choosing comparison options.

Comparison options

Satellite product:	Copernicus HRSI Pan-EU 20m Copernicus HRSI Pan-EU Gap-Filled 60m Copernicus SCE NH 1km Copernicus SCE Pan-EU 500m EUMETSAT HSAF H12 EUMETSAT HSAF H34 EUMETSAT HSAF H35 EUMETSAT HSAF H43
Satellite prod. threshold (%):
Insitu data threshold (cm):
Start date:
End date:
Min. points per location:	Auto

> Link to the product's official web page

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