Looking for an "Industrial" GNSS "Module"! - Page 1
Forum section: electronics / rf-microwave

author: Lord of nothing
author_rank: Super Contributor
timestamp: September 16, 2018, 02:54:27 pm
content: I am pissed... I ordered from Ebay some GNSS Receiver with an Ublox Chipset. I dont know if the are genuine or not.The U Center Show me that the just get an GPS Fix not Galileo and the other. So the bought just a GPS Version or the Chip is Fake. I also cant Send Commands into the Chipset.So I need some Genuine Product who works.Should I buy this:https://www.u-blox.com/en/product/evk-8evk-m8?I need an UBX 8 Chipset (who look like the latest Version) + SMA Antenna Port for an hight Gain Antenna and a USB Port for Power and Data.I also looked on ebay what the offer me and I found that:https://www.ebay.de/itm/Tiny-RTK-GPS-based-on-ublox-NEO-M8P-base-or-rover/172862649784?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20170511121231%26meid%3Db9c3709046a04423a164e2751136d0e6%26pid%3D100675%26rk%3D1%26rkt%3D15%26sd%3D172862649784%26itm%3D172862649784&_trksid=p2481888.c100675.m4236&_trkparms=pageci%3A02f6d450-b9c0-11e8-baca-74dbd1808123%7Cparentrq%3Ae2dd940e1650ac1fcd4b23d5fffe2cc9%7Ciid%3A1Thats what I looking for but I dont know the seller or if the are better "Modules" like that on the Marked?!Maybe someone with more knowledge about that topic can give some hints.

author: Beamin
author_rank: Super Contributor
timestamp: September 16, 2018, 03:03:06 pm
content: QuoteThat's great but what does it do? What do you use it for? How much does it cost?

author: Lord of nothing
author_rank: Super Contributor
timestamp: September 16, 2018, 03:22:21 pm
content: QuoteI will map the Railway Lines. The Companys refuse to give me permission to use there Data.So I need to Map it my self. I also will make Pictures, Trip Reports and other stuff so the side effect I can run the Tracking to. I try to use my Phone but there GNSS Receiver is crap the is up 100m beside of the Track.Well the max. Price... let me say it so that who is necessary. I saw that the Chipset from Ublox directly cost ~170€ so it should be <250€ for a "premium" one with Antenna Connector and Bias T.

author: Theboel
author_rank: Frequent Contributor
timestamp: September 16, 2018, 03:45:51 pm
content: I think in the "affordable class" accurate module You must look at PIKSI from swiftnavhttps://www.swiftnav.com/piksi-multiits not near your 250 euro but the result is excelent.but I suggest You to try first "NTRIP Client for Android" from lefebure.com its cost nothing.

author: Lord of nothing
author_rank: Super Contributor
timestamp: September 16, 2018, 03:57:38 pm
content: 600$ and maybe without Tax and + 20% Import Tax...I need the Ublox Chipset to use the Feature who Ublox offer me.

author: jc101
author_rank: Frequent Contributor
timestamp: September 16, 2018, 07:43:17 pm
content: You get an development kit from U-Blox direct, they will do basically what you want starting from ~€159 + shipping.https://www.u-blox.com/en/product/evk-8evk-m8Basically anything from China is going to be a "compatible" chipset, but as you found out none of the adjustable parameters actually do anything.

author: mmagin
author_rank: Frequent Contributor
timestamp: September 16, 2018, 10:38:05 pm
content: Quote from: Lord of nothing on September 16, 2018, 03:22:21 pmMost phones have pretty good GNSS receivers these days. Sounds more like the problem might be that you're using it from inside a mostly metal railway car. Unless you can place the antenna outside the vehicle, I'm not sure how switching to some Ublox receiver is going to help you.

author: Rerouter
author_rank: Super Contributor
timestamp: September 17, 2018, 12:53:25 am
content: Atleast on Sydney Australia trains. The passenger windows have metal embedded in them from the pattern printing. But the entry / exit doors are not. I would imagine 2 people, 1 per side recording the track on your phones pretty much held against the middle of the door height and then correlate the data.If you really want to get industrial. That would require a differential reciever. And that gets into $$$.What is your desired accuracy?

author: Lord of nothing
author_rank: Super Contributor
timestamp: September 17, 2018, 10:05:58 pm
content: QuoteWhat do you mean with? Sorry I dont understand your Post.QuoteNo mine.QuoteWhat the Railway operator told me here the dont have any Metal Coating.Quote1m.So I gues with an Antenna who have an hight Gain and Curacy I can receive Data even when some other Receiver got nothing. Its like my Satcom Antenna who allow me to receive Signals where an normal Areal get nothing.I would guess the size matter:

author: Rerouter
author_rank: Super Contributor
timestamp: September 18, 2018, 12:35:47 am
content: 1m absolute, e.g. +-0.5m or 1m relative, +-1m?In both cases your definitely in the range or RTK positioning, e.g. surveyors grade GPS,The is mainly due to you moving, so it requires a fixed base station to correct for the phase errors in the chain.My suggestion then would be to see what there rental costs in your area,

author: jc101
author_rank: Frequent Contributor
timestamp: September 18, 2018, 07:57:47 am
content: Quote from: Lord of nothing on September 17, 2018, 10:05:58 pmFollow the link, the development modules are small GPS units in cases, with external antenna connection and USB port for data & power. These kits look like they fit the bill of taking an external (active or passive) antenna with the connectivity you are looking for, without breaking the bank.

author: hagster
author_rank: Frequent Contributor
timestamp: September 18, 2018, 09:56:24 am
content: This has been said before in this and the other thread, but I will repeat it.To get an accurate fix you need direct line-of-sight toALLGNSS satellites above the mask angle(normally about 10° above horizon).Any signals received inside a train cabin will primarily NOT be line-of-sight. I.e they will have reflected off internal and external structures and hence travelled a longer distance to the receiver.If you place the GPS antenna against the window, you may get line of sight signals in that direction, but all other directions will be multi-path and hence have travelled further. This will likely give an offset fix in the direction of that window.I doubt you will get 1m accuracy even with an antenna mounted on the roof of a moving train. There will be too many structures around the track to disturb the position.In the other thread I recommended using Google Earth and using the imagery to work out the location of the track. I stick by this recommendation.

author: Lord of nothing
author_rank: Super Contributor
timestamp: September 22, 2018, 03:37:38 pm
content: So yesterday we took the Train to visit an Trade Fair and I used the Chineese GNSS Receiver.Now I look into the File and see some weird stuff there (see attachment).The Accuracy is not that bad for an onboard Train Reception with an crap GNSS "internal" Ceramic Antenna.Tomorrow I will Upload the Ublox File to my Webhoster so everyone who want can analyse them.The 3D Fix look very wired to.When I try to use the Output function of Ublox the dont work with Google Earth the File is just some kb big.Now I use the Google Earth Server Output and watch it in real time the work.For legal reason I cant upload the File where the Train Track + Tunnel are but I will show some Screen shots later.

author: hagster
author_rank: Frequent Contributor
timestamp: September 23, 2018, 09:30:47 pm
content: That accuracy is based on the dilution of precision(HDOP). Basically its mostly about the location of the satellites and SNT. Not about multipath.