Discuss DTV: SatelliteGuys Forum DTV USA Forum AVS Forum Digital Home Forum

   RabbitEars.Info   
Sitemap
  

Site Updates

Entries feed - Comments feed

Monday, September 2 2019

Doug Lung Shout Out to RabbitEars Search Map

Doug Lung wrote an article on Phase 4 of the repack for TV Technology, and in doing so, highlighted the RabbitEars Search Map as a tool to use for resolving reception issues. Thanks, Doug!

Link is here: https://www.tvtechnology.com/repack...

Tuesday, August 13 2019

Away from Keyboard

This is a note that I will be out of town and away from my keyboard until the middle of next week. I may find a bit of time here and there to work on things, but spent yesterday on a plane and am now several time zones away from home. Don't be surprised if you don't hear from me for a while.

Sunday, July 21 2019

RabbitEars Search Map Enters Public Beta

I'm pleased to launch the RabbitEars Search Map into public beta. I mentioned in my previous site update that I wanted to do it, but it stuck in my head and I decided to buckle down, dedicate most of my evenings and weekends to it. It's paid off, and I think it will work out really well.

So here's where to go see it: https://www.rabbitears.info/searchm...

It gives multiple means of choosing a location, the results have a handy link to a page that anonymizes the results, it's a ton faster than the existing search code, and there are nifty maps and diagrams to help understand what is going on in specific situations. Please feel free to provide as much feedback, good and bad, as possible. I want to know what I got right and what I got wrong. If I got things wrong, I can probably adjust them.

Beyond that, there are a few things I want to note about it.

First, if you have questions, please be sure to read the instructions. If they're not clear and/or don't answer your question, please let me know. I want them to hold the answers to all the questions people have, if possible.

Second, the terrain path profiles remain under construction. If at some point you look at it and it looks wrong or doesn't work, wait a few minutes and try again. I'm probably working on it. If it lasts a long time, let me know as I may not have noticed that I broke it, or you may have found a corner case that I need to investigate. But the key thing I'm still working on is trying to make it possible to either adjust the height of the display or, preferably, automate the resizing of the height. It's proving more difficult than I expected, and I decided not to hold the release of the whole tool over that one item.

Third, unlike other things on the site, the underlying database is a snapshot of the RabbitEars database as computed each morning. This was done to help speed things along; by dumping the database once into a simplified format, rather than having to parse all the LMS tables each time a search is run, the speed was drastically improved. Additionally, in the interest of consistency, these rows are stored along with the results for a study, so the information in the result link should remain consistent even if the database changes. The only exception is the repack data column; that is tied to live data because it may provide an insight into what's going on for someone who is confused about the current status of things.

Fourth... I feel like I'm forgetting something. I may update this post in the next few days if I think of more comments I wanted to make.

Finally, I'd like some people to check behind me on some of the math. I'm reasonably confident in it, but having additional eyes on it would make me feel a whole lot better. There are three things, specifically, that I am concerned about.

1) The formula for converting from dBuV/m to dBmV in the unit conversions. (The dBmV is then converted to either dBm or dBuV if necessary--those conversions are fine.) I derived the formula from two other formulas with common elements, but I'm not entirely certain I applied them correctly or even that my result makes sense. I don't do a lot of these types of conversions. My end result was:

20 * LOG10 ( ( POW ( 10, ( s.field / 20 ) ) / ( .021 * s.freq ) ) / 1000 )

Where s.field is the field strength in dBuV/m, and s.freq is the center frequency of the station in question. If someone has a different formula that is more correct, please let me know.

2) The formula for earth bulge as used in the terrain path profiles. I already changed it once.

( ( 1000 ) * ( 1 / ( 2 * 6370 ) ) * ( $dist * ( $terrain_len - $dist ) ) ) / ( 4 / 3 )

Where $dist is the distance from the beginning of the profile, and $terrain_len is the total length of the profile.

3) Also in the terrain path profile, I'm a bit concerned that I am oversimplifying the geometry. I'm just applying the earth bulge formula to the terrain path profile and that's it. Does anyone think it makes a significant difference whether or not I factor in the full geometry at the transmit and receive ends, or is this good enough?

Tuesday, July 9 2019

FCC Database Conversion and Site Usage Questions

While I moved most of the underlying FCC database-driven things on RabbitEars from CDBS to LMS about a year and a half ago, the CDBS facility table had remained in place rather than the new LMS facility table. That has now been remedied. It's not 100% finished, as particularly the Network Grid and the Statistics pages need a lot of work that I've yet to do. I'd say I'm more than 80% there, across the board, on the move to LMS. Some things definitely need some more polish, and if you come across something that doesn't work properly, please either comment here or e-mail me with a link to the page in question and a brief description of what's wrong. (I'm aware of the problem with the TSID page, just haven't done anything about it yet.)

I'm also working toward a new TVFool-like search function. I've shown a few people a new map-driven search page, and after some thought, I've decided to rewrite the actual search code as well, in an effort to speed it up. I don't know how long this will take, but I have the basic code design figured out, and it should help. I just need to implement it, which is of course the hard part.

On a semi-related note, are there people who use the Statistics page, or the various Advanced pages? I'm trying to figure out if there are things I can discontinue, as some of the maintenance is pretty hard on some of these things, and I don't really use them. So if nobody else does... (For the record, I am definitely keeping the Network Grid, just that it needs a complete overhaul as it is one of the slowest pages on the site. I want to do a complete overhaul and upgrade at once rather than upgrade it and then overhaul it.)

Friday, December 7 2018

Leave of Absence

My father-in-law passed away on December 2. I've been away from my e-mail since November 30 and do not know when I will return to it. I'm still making occasional minimal website updates. His obituary is here, an acknowledgment from the Virginia YMCA is here, a link to a single on which he played guitar in his youth is here, and the eulogy I gave at his funeral is below.

Continue reading...

Wednesday, October 31 2018

Further Update on the Google Maps Situation

As you may have noticed, with the exception of the Live Bandscan which I didn't code, pretty much every map on the site is now off of Google Maps except for the main set of coverage maps designed for individual stations. Unfortunately, I have to reproject all 57,000+ (that's 25+ GB) Longley-Rice coverage maps for display in the new format. As such, I'm currently packing them up to download to a powerful local computer, where I intend to do the reprojection offline. I expect to start that reprojection later today, and anticipate it will take at least two days, probably more. When that is finished, I'll upload them back up to the server and make the move.

I considered reprojecting the maps on the server, but a test case took 29 seconds, during which the server was sluggish. When I ran it on the local computer, it took less than 10 seconds. Suffice it to say, I concluded the local computer was the superior option.

While packing and unpacking are in process, the server may be slow as the tar command is/will be hogging the hard drive. Additionally, I plan to make no new coverage maps (or move existing ones from permits to new licenses) while the reprojection is occurring, lest I have to make modifications to a handful of individual map files after the fact.

The good news in all of this is that I've been planning to make a backup of the maps for several months anyway.

EDIT (November 3, 2018 at 5:26PM ET): And, it's done. All the maps, except for the Live Bandscan, should now be off of Google Maps. If you come across a map that still uses Google Maps, please let me know so I can correct it.

Friday, October 5 2018

Update on Google Maps Situation

Unfortunately, over the next few weeks (at minimum) there will be sporadic issues with the various maps until I am able to find the time to write new code to move away from Google Maps. They significantly cut the level of use permitted free of charge and RabbitEars now regularly exceeds that level. Since RabbitEars is not income-generating, I cannot afford such fees and will ultimately have to use a different map service.

Unlike others who have temporarily shut down their services entirely, I'm leaving mine running for the moment, but the error message will appear randomly until I make the move. Thank you for your patience.

Saturday, July 14 2018

Google Maps Changes

So, Google Maps is supposedly changing their policies on Monday, July 16. So far, other changes they made haven't impacted RabbitEars, and I don't know if this one will either. It's possible that maps on RabbitEars may stop working in the next few days and I may have to rewrite the pages to use an alternate map source. I'll cross that bridge only if I have to.

But if they stop working temporarily, that's why.

Thursday, April 26 2018

New Repack-Related Features

I've added two new repack-related features to RabbitEars and wanted to mention their existence here.

First, for LPTV stations filing displacements in the current displacement window, there is now a page listing all the displacements filed since the Closing Public Notice on April 13, 2017. You can find that here, or in the Updates dropdown menu as "Post-IA Displacements".

Second, much like during the DTV transition, stations are required to file status updates with the FCC. A page for those updates are now available as the 387 Viewer which is part of the Repack Tools.

Let me know if you have any opinions, requests, suggestions, or if you spot any bugs. Have a great one!

Wednesday, January 31 2018

Live Bandscan Returns; Scheduled Maintenance Coming

The Live Bandscan returned last week. Unfortunately, the backups were also toast and so we lost some (not all) data going back to the end of 2016. I think it's about back to where it needs to be, notwithstanding a few tweaks needed that I know about (like KSPR still showing up even though it's KYCW-LD now).

On the rest of the site, I'm back in the swing of trying to move things over from CDBS to LMS. The Tower Query and the Location Map now use LMS, and I've got the contours and population data regenerated for use with LMS entries. I wanted to make this post to note that the next big task related to that is going to be moving the coverage maps over, and probably the main listings right after. The result of this is that there will likely be a period of time that I hope is measured in hours and not days during which the maps will not work. I have to rename all the map files to line up with the new LMS ID numbers, and with more than 10,000 of them to pick through, even an automated process to do so will not be instantaneous. I do not yet know exactly when this will be, but I'm hoping it's overnight one night soon. I know there will be some amount of manual cleanup needed afterward, so it may not all be back up and running right away.

I also want to flag that things may be broken here and there even after the maps are back up and running and the main listings are moved into LMS format. The CDBS database has only been updated with TV data two or three times in the past month and a half, and so I'm urgently trying to get away from it. My plan had been to try to transition everything over slowly and as seamlessly as I could, but the lack of updates to CDBS and the coming LPTV filing window are making me rush over to LMS. So, once the maps come back online, notwithstanding Canadian and Mexican data which will likely remain in a state of limbo for several weeks at a minimum, please let me know if you trip over anything that doesn't work properly. With as many features as RabbitEars has, I can't really test it all, and it's easy to overlook things.

The last note I want to make is that I'm not actually making an entirely clean break from CDBS just yet. To those that are familiar with the data structure of the FCC databases, I'm still using the facility table from CDBS but then relating it to the application_facility table in LMS. I'm doing this to hurry the conversion process along, and will ultimately have to go back and adjust the code again to make it use the facility table in LMS instead. Since the facility table changes so infrequently and time is of the essence, I'm leaving RabbitEars on the CDBS facility table for now.

- page 1 of 10