Daniel Estévez
@destevez.net
Everything space & RF. Amateur radio operator (EA4GPZ / M0HXM). PhD in Mathematics from Univ. Autónoma de Madrid. he/him
I have made a new release of the Maia SDR firmware. This is a maintenance release that updates dependencies and includes some USB Ethernet connectivity improvements to Android devices.
November 9, 2025 at 7:21 PM
I have made a new release of the Maia SDR firmware. This is a maintenance release that updates dependencies and includes some USB Ethernet connectivity improvements to Android devices.
New blog post: sigmf-toolkit. I present a new Python package I've made and showcase one of its tools, which adds to a SigMF file annotations for each packet in a PCAP file. This is a good way of doing protocol analysis and debugging across the physical and upper layers. destevez.net/2025/11/sigm...
November 2, 2025 at 2:14 PM
New blog post: sigmf-toolkit. I present a new Python package I've made and showcase one of its tools, which adds to a SigMF file annotations for each packet in a PCAP file. This is a good way of doing protocol analysis and debugging across the physical and upper layers. destevez.net/2025/11/sigm...
New blog post: Non-coherent m-FSK BER. Another short post in which I derive the following formula for the symbol error rate of non-coherent m-FSK and validate it using simulations. destevez.net/2025/10/non-...
October 25, 2025 at 9:28 AM
New blog post: Non-coherent m-FSK BER. Another short post in which I derive the following formula for the symbol error rate of non-coherent m-FSK and validate it using simulations. destevez.net/2025/10/non-...
New blog post: Non coherent FSK BER. A short note on how to compute the well known formula for the bit error rate of FSK, because I can never quickly find a source which contains this derivation. destevez.net/2025/10/non-...
Non-coherent FSK BER – Daniel Estévez
destevez.net
October 24, 2025 at 10:22 AM
New blog post: Non coherent FSK BER. A short note on how to compute the well known formula for the bit error rate of FSK, because I can never quickly find a source which contains this derivation. destevez.net/2025/10/non-...
New blog post: 10 years of blogging. Today it's 10 years since I wrote the first post in my blog. To celebrate I've made a summary of what I have been posting during these years. It can serve as a good index for people who are not too familiar with the blog's contents.
destevez.net/2025/10/10-y...
destevez.net/2025/10/10-y...
10 years of blogging – Daniel Estévez
destevez.net
October 16, 2025 at 7:53 AM
New blog post: 10 years of blogging. Today it's 10 years since I wrote the first post in my blog. To celebrate I've made a summary of what I have been posting during these years. It can serve as a good index for people who are not too familiar with the blog's contents.
destevez.net/2025/10/10-y...
destevez.net/2025/10/10-y...
Reposted by Daniel Estévez
New blog post: Synthetic aperture radar autofocus and calibration.
Synthetic aperture radar autofocus and calibration
3D trajectory position error estimation autofocus, antenna pattern normalization, and polarimetric calibration for drone mounted SAR radar.
hforsten.com
October 7, 2025 at 3:44 PM
New blog post: Synthetic aperture radar autofocus and calibration.
Would you like to work in RF signal processing at Muon Space
for SIGINT and RF science missions with a team of great engineers including myself? If you are eligible to work on ITAR/EAR and interested in helping us grow our cloud-based and onboard processing, my DMs are open.
for SIGINT and RF science missions with a team of great engineers including myself? If you are eligible to work on ITAR/EAR and interested in helping us grow our cloud-based and onboard processing, my DMs are open.
RF Digital Signal Processing Specialist - Geospatial Intelligence
Mountain View, CA or Remote
job-boards.greenhouse.io
October 8, 2025 at 11:45 AM
Would you like to work in RF signal processing at Muon Space
for SIGINT and RF science missions with a team of great engineers including myself? If you are eligible to work on ITAR/EAR and interested in helping us grow our cloud-based and onboard processing, my DMs are open.
for SIGINT and RF science missions with a team of great engineers including myself? If you are eligible to work on ITAR/EAR and interested in helping us grow our cloud-based and onboard processing, my DMs are open.
Reposted by Daniel Estévez
Synthetic aperture radar vs Gopro.
October 4, 2025 at 3:50 PM
Synthetic aperture radar vs Gopro.
New blog post: Flip-flop timing experiments. I design an ASIC flip-flop using Magic and play around with some ngspice timing simulations of output delay, setup and hold. I have made my flip-flop (top) as small as possible, so it is half the area as the standard cell (bottom).
September 28, 2025 at 9:03 PM
New blog post: Flip-flop timing experiments. I design an ASIC flip-flop using Magic and play around with some ngspice timing simulations of output delay, setup and hold. I have made my flip-flop (top) as small as possible, so it is half the area as the standard cell (bottom).
New blog post: 10 GHz FMCW radar LO board. I've finished assembling and testing my ADF4158+HMC391 3.9-4.45 GHz LO board, for which I asked for reviews a few months ago. In the post I explain some aspects of the board design, and the software I've written and testing I've done.
September 4, 2025 at 9:42 AM
New blog post: 10 GHz FMCW radar LO board. I've finished assembling and testing my ADF4158+HMC391 3.9-4.45 GHz LO board, for which I asked for reviews a few months ago. In the post I explain some aspects of the board design, and the software I've written and testing I've done.
New blog post: Multispectral analysis of the Tres Cantos wildfire with Sentinel-2 data. This image shows vegetation surviving the fire in green, vegetation lost by the fire in magenta, and areas affected by the fire but with less vegetation loss (dry grass) in blue.
August 19, 2025 at 10:40 AM
New blog post: Multispectral analysis of the Tres Cantos wildfire with Sentinel-2 data. This image shows vegetation surviving the fire in green, vegetation lost by the fire in magenta, and areas affected by the fire but with less vegetation loss (dry grass) in blue.
On Monday there was a large wildfire in Tres Cantos, Madrid, Spain, which is where I live (my family, friends and I are all okay). Today I have found some Airbus Space Pléiades Neo imagery that shows the extent of the fire more accurately than all other source I've seen.
August 13, 2025 at 10:00 AM
On Monday there was a large wildfire in Tres Cantos, Madrid, Spain, which is where I live (my family, friends and I are all okay). Today I have found some Airbus Space Pléiades Neo imagery that shows the extent of the fire more accurately than all other source I've seen.
I've made new releases of gr-satellites: 5.8.0 (GNU Radio 3.10), 4.15.0 (GNU Radio 3.9), 3.22.0 (GNU Radio 3.8). This will be the last release supporting GNU Radio 3.9 and 3.8. Maintainance for these branches will stop now.
August 1, 2025 at 12:08 AM
I've made new releases of gr-satellites: 5.8.0 (GNU Radio 3.10), 4.15.0 (GNU Radio 3.9), 3.22.0 (GNU Radio 3.8). This will be the last release supporting GNU Radio 3.9 and 3.8. Maintainance for these branches will stop now.
New blog post: n78 band 5G NR recordings. I comment on some recordings I have made that are representative of the current state of 5G deployment on this band in Spain (100 MHz cells for Movistar and Orange, 90 MHz cell for Vodafone).
July 17, 2025 at 10:32 AM
New blog post: n78 band 5G NR recordings. I comment on some recordings I have made that are representative of the current state of 5G deployment on this band in Spain (100 MHz cells for Movistar and Orange, 90 MHz cell for Vodafone).
Reposted by Daniel Estévez
Wrote code for SAR image antenna pattern normalization and polarimetric calibration (channel imbalance and crosstalk). Image looks very nice now.
July 13, 2025 at 2:10 PM
Wrote code for SAR image antenna pattern normalization and polarimetric calibration (channel imbalance and crosstalk). Image looks very nice now.
Some months ago I shared my design of a PCB with an ADF4158 PLL/waveform synth and HMC319 VCO intended as an LO source for an FMCW radar in the 10 GHz band. I have finished soldering all the components, and the HMC319 appears to be working. The next step is the ADF4158 config.
July 13, 2025 at 11:33 AM
Some months ago I shared my design of a PCB with an ADF4158 PLL/waveform synth and HMC319 VCO intended as an LO source for an FMCW radar in the 10 GHz band. I have finished soldering all the components, and the HMC319 appears to be working. The next step is the ADF4158 config.
New blog post: Galileo OSNMA chain renewal. OSNMA is the Galileo open service navigation message authentication system, which authenticates cryptographically the navigation data broadcast by the satellites. Here I comment on a TESLA chain renewal test done on Tuesday.
July 12, 2025 at 3:49 PM
New blog post: Galileo OSNMA chain renewal. OSNMA is the Galileo open service navigation message authentication system, which authenticates cryptographically the navigation data broadcast by the satellites. Here I comment on a TESLA chain renewal test done on Tuesday.
New blog post: About FLLs with band-edge filters. This post is motivated by some bugs in the @gnuradio.org FLL that I've been working on fixing. I explain what band-edge filters are, and how they can be used in an FLL.
July 2, 2025 at 10:58 AM
New blog post: About FLLs with band-edge filters. This post is motivated by some bugs in the @gnuradio.org FLL that I've been working on fixing. I explain what band-edge filters are, and how they can be used in an FLL.
New blog post: Z-Sat VHF transmissions. Recently Daniel Ekman has noticed that Z-Sat, a Japanese satellite launched in 2021 that has an amateur radio payload, is transmitting a digital signal continuously. Here I analyze a recording of this signal.
June 30, 2025 at 7:12 PM
New blog post: Z-Sat VHF transmissions. Recently Daniel Ekman has noticed that Z-Sat, a Japanese satellite launched in 2021 that has an amateur radio payload, is transmitting a digital signal continuously. Here I analyze a recording of this signal.
New blog post: 5G NR PDSCH. In this post I show how to decode the 5G PDSCH (downlink data) by using the SIB1 from an srsRAN gNB recording as an example. I go into the details of how LDPC and the rest of rate matching and other encoding work.
June 13, 2025 at 7:59 AM
New blog post: 5G NR PDSCH. In this post I show how to decode the 5G PDSCH (downlink data) by using the SIB1 from an srsRAN gNB recording as an example. I go into the details of how LDPC and the rest of rate matching and other encoding work.
Reposted by Daniel Estévez
Found motivation to write some SAR processing code. Fast factorized backprojection generates several small polar format images and then interpolates them to one big image. It's faster, but has slightly worse image quality due to all the interpolations.
June 1, 2025 at 5:42 PM
Found motivation to write some SAR processing code. Fast factorized backprojection generates several small polar format images and then interpolates them to one big image. It's faster, but has slightly worse image quality due to all the interpolations.
Reposted by Daniel Estévez
Measuring Radio Recombination Lines (RRL) with the Dwingeloo telescope (@radiotelescoop.bsky.social), in the Omega Nebula (M17/W38).
May 25, 2025 at 2:08 PM
Measuring Radio Recombination Lines (RRL) with the Dwingeloo telescope (@radiotelescoop.bsky.social), in the Omega Nebula (M17/W38).
New blog post: 5G NR PDCCH. In this post I show how to decode the Physical Downlink Control Channel, by using as example the PDCCH for the SIB1 in a srsRAN gNB recording. The PDCCH is used to transmit control information such as downlink scheduling and uplink grants.
May 10, 2025 at 7:23 PM
New blog post: 5G NR PDCCH. In this post I show how to decode the Physical Downlink Control Channel, by using as example the PDCCH for the SIB1 in a srsRAN gNB recording. The PDCCH is used to transmit control information such as downlink scheduling and uplink grants.
New blog post: Time-dependent delay in @gnuradio.org. I have added a new block to gr-satellites that performs a time-varying delay. This block works similarly to the Doppler correction block: the delay versus time is defined by a text file prepared beforehand.
May 3, 2025 at 6:20 PM
New blog post: Time-dependent delay in @gnuradio.org. I have added a new block to gr-satellites that performs a time-varying delay. This block works similarly to the Doppler correction block: the delay versus time is defined by a text file prepared beforehand.
Is there anyone using gr-satellites in GNU Radio 3.8 or 3.9? What would be the impact of stopping gr-satellites releases for these GNU Radio versions? I'm considering dropping support for the maint-3.9 and maint-3.8 branches, since these cause more trouble each day.
April 30, 2025 at 9:42 AM
Is there anyone using gr-satellites in GNU Radio 3.8 or 3.9? What would be the impact of stopping gr-satellites releases for these GNU Radio versions? I'm considering dropping support for the maint-3.9 and maint-3.8 branches, since these cause more trouble each day.