Introduction Saturday November 5th was an ideal evening to measure a Lunar from my balcony. It was unseasonably warm at 20degC and I had just removed all the gear, as my balcony is going to be rebuilt for the third time in five years, so I might as well enjoy the last few jack hammer… Continue reading Lunar Distance – DST to EST
Category: Navigation
Navigation: Celestial, Sextant, Equipment
RTL-SDR for VHF Marine Scanner on SDR#
Introduction Recently I was approached for advice on frequency scanning. My first thought was a traditional approach of starting at the base frequency, stepping by the channel spacing and doing a power evaluation. If greater than a threshold, then hold and attempt a decode. Before building a prototype in GNU Radio, I thought I would… Continue reading RTL-SDR for VHF Marine Scanner on SDR#
RTL-SDR for HF WWV Propagation
Introduction Recently I was in Costa Rica (Ref.1) and I used WWV to set my watch for UTC time to accurately read my sextant. We tend to take time for granted now with the Internet & GPS, but time stations like WWV still provide an essential service. WWV (Ref.2) can also be used to study… Continue reading RTL-SDR for HF WWV Propagation
RTL-SDR for AIS & ADS-B on Local Map+
Introduction In previous posts I looked at receiving both AIS & ADS-B on SDRangel (Ref.1) as well as displaying them on OpenCPN using a combination of aisdeco2 & MULTIPSK (Ref.2). The immediate application for this is for an off shore oil/exploration rig, where knowledge of local ships is important (AIS), as well as incoming/outgoing helicopters… Continue reading RTL-SDR for AIS & ADS-B on Local Map+
RTL-SDR for UTC Time in the Tropical Rainforest
Introduction In order to take an accurate sextant sight, we need to have precise time, ideally within 1 second. The Earth revolves at 360deg/24hours = 15deg/1hour = 15min_arc/min_time = 1min_arc = 4secs_time. A shortwave receiver can be used to get this time using international time stations. WWV UTC Shortwave Time Station In Toronto, time stations… Continue reading RTL-SDR for UTC Time in the Tropical Rainforest