Unfortunately ALS data in Lower Saxony is still not available as open data. However, there is a contract which makes the data available to th NW-FVA for research purposes. First data is available for the year 2010 and since then there have been regular updates from year to year. @fig-als-lower-saxony-year provides an overview on the year of data acquisition in Lower Saxony by region. A constantly updated version is also available from LGLN from lgln.niedersachsen.de.
Availability of ALS data in Lower Saxony by year of acqusition
Since one of the main porpuses of ALS data was originally (and still is) the creation of digital terrain models, data is usually collected outside of the vegetation period (leaf-off) to yield a higher penetration rate to the ground. However, the exact date of the flight within each year varies with each campaign. @fig-als-lower-saxony-month provides an overview on the month in which the data was collected.
Availability of ALS data in Lower Saxony by month of acqusition
Since 2020 the first regions had a repeated coverage of ALS data. When, how and where areas will be covered by new campaigns remains unclear, as there is no public information on these plans. According to the DTM quality standard there has to be a timeliness of less than 10 years for terrain models, however personal information suggests that additional data is assessed based on the financial scope.