There has been a recent surge in interest in a software package written by Cees Bassa known as ‘strf’, Sattools Radio Frequency. Once over the initial installation and basic usage hump users quickly reach a wall about how to use the software because of a limited understanding of orbital dynamics. I hope this brief post will help users understand some of the basic concepts so they can use strf as a tool.
Just when everyone thought the story of IMAGE was going to have a Hollywood ending she has displayed a knack for dramatic flare.
On 2018-02-25 at 02:19:19.459 UTC IMAGE ended an approximately 48 hour series of off/on sequences of its TT&C beacon and returned to silence. It’s been over two days now and the beacon has not returned to the air.
The signal sequence in the image above shows the last few minutes of IMAGE’s transmissions. Continue reading “Space Strikes Back, IMAGE Returns to Silence…”
Over the past week the station has been dedicated to an S-band scan looking for new targets and refreshing the frequency list, triggered by the recent launch of the mysterious ZUMA mission. This tends to be a semi-annual activity as it can eat up a lot of observing resources even with much of the data gathering automated the data reviewing is tedious.
Upon reviewing the data from January 20, 2018, I noticed a curve consistent with an satellite in High Earth Orbit (HEO) on 2275.905MHz, darn not ZUMA… This is not uncommon during these searches. So I set to work to identify the source.
A quick identity scan using ‘strf’ (sat tools rf) revealed the signal to come from 2000-017A, 26113, called IMAGE.
A Delta IV rocket launched the classified NROL-47 satellite from Vandenberg in California on January 12, 2018. The satellite is believed to be the 5th member of the Topaz (FIA Radar) project, radar satellites operating in 1100km altitude, 123 degree inclined retrograde orbits. Broadcast warnings for the NROL-47 launch placed the impact areas of the solid rocket motors, the first stage and the de-orbit area of the second stage at markedly different locations than with previous Topaz launches, indicating an orbital inclination around 108 degrees. Hence, it was not clear if NROL-47 is a Topaz satellite. Continue reading “NROL-47 transmits at S-band”