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Questions tagged [ais]

The Automatic Identification System (AIS) is an automatic tracking system used on ships and by vessel traffic services (VTS) for identifying and locating vessels by electronically exchanging data with other nearby ships, AIS base stations, and satellites.

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Ship maritime AIS information API

Is there an API or Web Service that can be used to read AIS data? Most links I read starting at Wikipedia (http://en.wikipedia.org/wiki/Automatic_Identification_System) say that AIS data is freely available but I'm having a hard time finding a…
James Cadd
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Building AIS Messages Decoder

I used to decode AIS messages with theis package (Python) https://github.com/schwehr/noaadata/tree/master/ais until I started getting a new format of the messages. As you may know, AIS messages come in two types mostly. one part (one message) or…
Shad
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How to recreate coordinate transformation from vesselfinder (EPSG:4326 to EPSG:3857)?

I'm currently trying to figure out how vesselfinder.com calculates its Box Boundaries (bbox) which they use to query data from their backend. Given an input like: lat, lon = 59.8230, 22.9586 They fetch data by using this bbox:…
user8563312
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How can I combine nom parsers to get a more bit-oriented interface to the data?

I'm working on decoding AIS messages in Rust using nom. AIS messages are made up of a bit vector; the various fields in each message are an arbitrary number of bits long, and they don't always align on byte boundaries. This bit vector is then ASCII…
squidpickles
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Python libais documentation

I cannot find any documentation about what does the ais.decode means. I do not know from where these categories (e.g. u'slot_timeout') had been chosen. I tried to find it on Internet, but I found many different solution from different web sites (no…
Chènevis
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How to fix AIS COG Values

I am currently working with AIS dataset containing fields MMSI, Timestamp, LAT, LON, SOG, COG, etc. Here, COG is course over ground, and supported COG value ranges from 0 to 360 degrees. But the dataset contains negative values in some rows. I like…
faring
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How to transmit AIS message with GNURadio

I'm having trouble getting this to work: https://github.com/trendmicro/ais The software contains a GNURadio Companion flow graph that sends AIS Messages to a USRP. I've installed the included gr-aistx library, and everything seems to run smoothly.…
cwittah
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NMEA AIS position messages complete UTC timestamp obtention

After decoding AIVM sentences using gpsdecode I have a buch of json estructures, each one with all the data of a message type, for…
Lanas
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ReactJS - JavaScript: Filter function does not work properly

I am building a boat visualizer using AISHub APIs. After inquiring the APIs I am able to obtain a json file with thousands of vessels, but I filter only the vessels I am interested in, and inject them into a table on a webpage. The API gives the…
Emanuele
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Is it possible to approximate missing position data by imputation?

I would like to increase the density of my AIS or GPS data in order to carry out more precise analyses afterwards. During my research I came across different approaches like interpolation, filtering or imputation. With the first two approaches,…
Braveness
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R binary / decimal conversion confusion - AIS data

I'm working with AIS (automatic Identification System) data for positioning vessels. I was able to follow this guide to decode almost all the bit of information successfully (when compared to online decoding done here). However, I'm running into a…
user2602640
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Distance Between Points Within Radius at Time Intervals

Data looks like this: ID Lat Long Time 1 3 3 00:01 1 3 4 00:02 1 4 4 00:03 2 4 3 00:01 2 4 4 00:02 2 4 5 00:03 3 5 2 00:01 3 5 3 00:02 3 5 4 00:03 4 9 9 00:01 4 9 8 00:02 4 8 8 …
bstrain
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How do you link multipart AIS messages?

The message format is !AIVDM,2,1,,B,177KQJ5000G?tO`K>RA1wUbN0TKH,0*5C The second field (in this case, 2), designates the number of parts in the AIS message and the third field (in this case, 1) indicates the part or fragment sequence. If the…
AAsk
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TCP server option not working in program running on RPi

I have this program running on my RPi(sudo ais_rx.tcp -d --tcp): https://github.com/chgans/gr-ais I have gotten it running and can create an output file. I can not get the TCP server option to function. Netstat --tcp shows nothing. Telnet…
LrakWortep
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AIS SOG: Handling Negative Values

I'm working with an AIS dataset. The SOG (speed over ground) field has negative values, but the supported values are between 0 and 102.2 knots. How should I handle these values?
afonsomm
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