SuperDARN Hokkaido radar range offset issue It was found that the rawacf / fitacf data of the SuperDARN Hokkaido radar contained range value offset until 0917 UT on December 25, 2009. When the data have range offset, the real range is always farther away from the radar. For example, if the range offset is 2, the data stored at range 1 location should show the value at the real range 3. In order to describe the offset values, we classify the total period of radar operation into four. 1. Period of using analog receiver 2. Periof of using digital receiver with 1MHz filter 3. Period of using digital receiver with 7kHz narrowband filter 4. Period after adjustment was applied Each corresponds to the following period: 1. till 2008.9.3 0000 UT 2. since 2008.9.3 1412 UT till 2009.6.30 1127 UT since 2009.6.30 2340 UT till 2009.7.1 0420 UT since 2009.7.1 2341 UT till 2009.7.3 1526 UT 3. since 2009.6.30 1128 UT till 2009.6.30 1738 UT since 2006.7.1 0625 UT till 2007.7.1 2156 UT since 2009.7.3 1527 UT till 2009.12.25 0917 UT 4. since 2009.12.25 0917 UT to present The range gate offset values for these periods are as follows: 1. 45 km mode: 0 gates (0 km) 15 km mode: 2 gates (30 km) 2. 45 km mode: 2 gates (90 km) 15 km mode: 5 gates (75 km) 3. 45 km mode: 2 gates (90 km) 15 km mode: 4 gates (60 km) 4. 45 km mode: 0 gates (0 km) 15 km mode: 0 gates (0 km) Solution using the go command installed at STEL computer: If you are analyzing the data for 2009.6.12, 0000-0200 UT, which was during 15 km range resolution mode, it corresponds to period #2, indicating the range gate offset of 5 (75 km). You can adjust it by using the 'archive' command with 'tada' parameter as: archive,'hok',2009061200,24,/new,tada=75 Then the range offset information is adjusted.