Eredar measurements of Halema'uma'u lava lake level (NERC Grant NE/N009312/1)
Surface level measurements of the Halema'uma'u lava lake, Hawaii. Surface level was measured from a site at the crater rim (19.40452 N 155.27944 W 1125 M a.s.l) using the Eredar radar system, a ground-based X-band FMCW radar (described in detail here: https://doi.org/10.1029/2018GL079177). Due to technical problems, the radar did not acquire continuously throughout its deployment. The dataset contains three blocks of successful continuous measurement periods (all times in UTC): 10 Jan 22:18 -> 11 Jan 08:46 11 Jan 21:24 -> 12 Jan 22:49 14 Jan 20:27 -> 14 Jan 23:01 Measurements were taken at a rate of ~1 Hz, using a 20 ms 400 MHz bandwidth Linear Frequency Modulated chirp centred at 10.25 GHz.
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Data Quality
Raw radar returns have been converted to range using standard FMCW processing. The width of the radar beam (3 degrees) coupled with the oblique viewing angle (antennas at -36.5 degrees from horizontal) results in a broad return spanning many range cells from the surface of the lake. A Gaussian fit has been made to this return, and the range to the lake taken as the range of the peak of the Gaussian. Ranges have been corrected for viewing geometry and converted to height above sea level based on the altitude of the radar system which was measured using a handheld GPS. The rapidly changing surface texture of the lake has resulted in considerable scatter in the Gaussian fit and therefore calculated height of the lake. A moving average (we recommend a window size of ~50 samples) can be used to reduce this and resolve fluctuations in lake level.
INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of Geology
Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services
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