The official GNSS raw measurements fetched via GNSS logger app provides the following parameters :
TimeNanos
LeapSecond
TimeUncertaintyNanos
FullBiasNanos
BiasNanos
BiasUncertaintyNanos
DriftNanosPerSecond
DriftUncertaintyNanosPerSecond HardwareClockDiscontinuityCount
Svid
TimeOffsetNanos
State
ReceivedSvTimeNanos
ReceivedSvTimeUncertaintyNanos
Cn0DbHz
PseudorangeRateMetersPerSecond
PseudorangeRateUncertaintyMetersPerSecond
I'm looking for the raw pseudorange measurements PR from the above data. A little help?
Reference 1: https://github.com/google/gps-measurement-tools
Reference 2 : https://developer.android.com/guide/topics/sensors/gnss
Pseudorange[m] = (AverageTravelTime[s] + delta_t[s]) * speedOfLight[m/s]
where: m - meters, s - seconds.
Try this way:
Select satellites from one constellation (at first try with GPS).
Chose max value of ReceivedSvTimeNanos.
Calculate delta_t for each satellite as max ReceivedSvTimeNanos minus current ReceivedSvTimeNanos(delta_t = maxRst - curRst).
Average travel time is 70 milliseconds, speed of light 299792458 m/s. use it for calculation.
Don't forget to convert all values to the same units.
For details refer to this pdf and UserPositionVelocityWeightedLeastSquare class
Unfortunately Android doesn't provide pseudorange directly from the API - you have to calculate this yourself.
The EU GSA has a great document here that explains in detail how to use GNSS raw measurements in section 2.4:
https://www.gsa.europa.eu/system/files/reports/gnss_raw_measurement_web_0.pdf
Specifically, section 2.4.2 explains how to calculate pseudorange from the data given by the Android APIs. It's literally pages of text, so I won't copy the whole thing in-line here, but here's the Example 1 they share for a Matlab code snippet to compute the pseudorange for Galileo, GPS and BeiDou signals when the time-of-week is encoded:
% Select GPS + GAL TOW decoded (state bit 3 enabled)
pos = find( (gnss.Const == 1 | gnss.Const == 6) & bitand(gnss.State,2^3);
% Generate the measured time in full GNSS time
tRx_GNSS = gnss.timeNano(pos) - (gnss.FullBiasNano(1) + gnss.BiasNano(1));
% Change the valid range from full GNSS to TOW
tRx = mod(tRx_GNSS(pos),WEEKSEC*1e9);
% Generate the satellite time
tTx = gnss.ReceivedSvTime(pos) + gnss.TimeOffsetNano(pos);
% Generate the pseudorange
prMilliSeconds = (tRx - tTx );
pr = prMilliSeconds *Constant.C*1e-9;
I'm a total newbie when it comes to Natty and Antler. Up to now, Natty has been great and has parsed dates with no problems. Recently we have started to receive a new date and time format which Natty has trouble extracting.
Mon 29 Feb 09:00:00 2016
It cannot extract the year due to it being separated from the rest of the date.
I've been trying to add my own format into DateParser, where it could pick up on this format as it does with any other.
I've made the following changes:
date_time: Added an extra rule called custom_dates which will be the new rule for my format
date_time
: (
(date)=>date (date_time_separator explicit_time)?
| explicit_time (time_date_separator date)?
| custom_dates
) -> ^(DATE_TIME date? explicit_time?)
| relative_time -> ^(DATE_TIME relative_time?)
;
custom_date: My new rule
custom_date
: relaxed_day_of_week WHITE_SPACE relaxed_day_of_month WHITE_SPACE relaxed_month (date_time_separator explicit_time)? relaxed_year
-> ^(EXPLICIT_DATE relaxed_day_of_week relaxed_day_of_month relaxed_month relaxed_year (date_time_separator explicit_time)?)
;
When I try to build Natty with my changes, it just hangs, and never finishes. The output up to that point is:
Decision can match input such as "COMMA WHITE_SPACE INT_00 INT_00" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
warning(200): com\joestelmach\natty\generated\DateParser.g:444:73:
Decision can match input such as "COMMA WHITE_SPACE INT_00 {INT_13..INT_19, INT_20..INT_23}" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
warning(200): com\joestelmach\natty\generated\DateParser.g:496:45:
Decision can match input such as "WHITE_SPACE IN {COMMA, WHITE_SPACE}" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
warning(200): com\joestelmach\natty\generated\DateParser.g:504:77:
Decision can match input such as "WHITE_SPACE IN {COMMA, WHITE_SPACE}" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
Am I possibly going the wrong way about this? I've taken a look at the Natty and ANTLR v3 documentation but there isn't much to go on.
Thanks in advance
EDIT:
As requested in the comments below. I've added in where the first warning occurs. However what I've included above is just a small snapshot of the dozens of warnings that have been in there before I modified any code with my own rules
The first warning appears in the date_time_separator
date_time_separator
: WHITE_SPACE (AT WHITE_SPACE)?
| WHITE_SPACE? COMMA WHITE_SPACE? (AT WHITE_SPACE)?
| T
;
One observation I've made is when I changed my rule to always include the time
custom_date
: relaxed_day_of_week WHITE_SPACE relaxed_day_of_month WHITE_SPACE relaxed_month (date_time_separator explicit_time) relaxed_year
-> ^(EXPLICIT_DATE relaxed_day_of_week relaxed_day_of_month relaxed_month relaxed_year (date_time_separator explicit_time)?)
;
When I compile I receive this error:
error(202): com\joestelmach\natty\generated\DateParser.g:831:3: the decision cannot distinguish between alternative(s) 1,2 for input such as "INT_00 INT_00 INT_00 EOF"
Looking at line 831 is where the explicit_time resides. I cannot find anything on StackOverflow or otherwise as to what this error means. I assume this error means that there is some ambiguity between the two possible routes. However I don't understand why merely adding in my code should cause an error.
explicit_time_hours_minutes returns [String hours, String minutes, String ampm]
: hours (COLON | DOT)? minutes ((COLON | DOT)? seconds)? (WHITE_SPACE (meridian_indicator | (MILITARY_HOUR_SUFFIX | HOUR)))?
{$hours=$hours.text; $minutes=$minutes.text; $ampm=$meridian_indicator.text;}
-> hours minutes seconds? meridian_indicator?
| hours (WHITE_SPACE? meridian_indicator)?
{$hours=$hours.text; $ampm=$meridian_indicator.text;}
-> hours ^(MINUTES_OF_HOUR INT["0"]) meridian_indicator?
;
Messy, complicated question, but here goes. I'm working on an integration project with Google Checkout, and there is a Google Checkout GWT service that returns the currency conversion rates used by the Checkout web interface to convert USD into local currencies. This endpoint is hosted at https://market.android.com/publish/gwt/, and staring at Firebug I see this going to the server:
7|0|6|https://market.android.com/publish/gwt/|FCCA4108CB89BFC2FEC78BA7363D4AF6|com.google.wireless.android.vending.developer.
shared.MerchantService|getCurrencyExchangeRates|com.google.common.money.CurrencyCode/112449834|java.util.ArrayList/4159755760
|1|2|3|4|2|5|6|5|235|6|13|5|18|5|81|5|53|5|72|5|102|5|121|5|177|5|175|5|205|5|204|5|55|5|86|-1|
and this being returned
//OK[235,3,'D0JA',2,86,3,'CXXg',2,55,3,'DW2A',2,204,3,'X9NA',2,205,3,'EuvA',2,175,3,'VIig',2,177,3,'E2Dw',2,121,3,'E4ziA',2,1
02,3,'do$Q',2,72,3,'T82w',2,53,3,'Ds0Q',2,81,3,'Cq5g',2,18,3,'Dlfg',2,13,1,["com.google.common.collect.RegularImmutableList/4
40499227","com.google.common.money.SimpleMoney/627983206","com.google.common.money.CurrencyCode/112449834"],0,7]
Forgive the odd formatting: can't quite get the code block to format right.
Wandering the web for hours on end I was able to determine that the RegularImmutableList class is in the Guava libraries (at http://code.google.com/p/guava-libraries/). What I'm looking for is:
I can't find the com.google.common.money.SimpleMoney or com.google.common.money.CurrencyCode classes anywhere: anyone seen them?
The GWT wire format appears to be an odd JSON string. I see various references to Google Groups messages talking about descriptions of the wire format, but can't find the underlying messages or any coherent reference that would let me reverse this: anyone have a handle on a handy reference? If I can at least understand WHAT the encoding is I might be able to get away without the class files from question 1 above.
I started wandering through the Android Market api library at http://code.google.com/p/android-market-api/, figuring they have to have done SOME of the Android Market communication integration, and they appear to have done so using protobufs. Is there any decent reference for the GWT/protobufs communication bits?
The underlying reason for this craziness is that I need to be able to take regular exchange rate values from Google Checkout so when I'm importing sales transactions in foreign currencies I can do the conversion at the prevailing rate at the time of the transaction. The current Checkout reporting formats do NOT provide this, so most folks end up using alternative sources of exchange rates that don't match what Google uses. It is clearly a shortcoming on the part of Google Checkout's integration interface, but if we got started on shortcomings of Google Checkout's interface we'd be here all week. My intention is to poll the Checkout interface for newly fulfilled orders and then request the appropriate exchange rate table so I can figure out in near real-time what the incoming payments are. I've got the polling bit down pat but can't quite get past the exchange rate bit.
While trying to create a script to bulk upload in-app products for my application (CSV upload constantly failed with obscure error messages), I have managed to understand the GWT AJAX protocol.
It's actually pretty simple, except it requires you to know structure of all used classes. Or guess it, as is the case with internal classes used by Google. :)
I'll use examples from the question to explain the protocol in detail.
Request format
7|0|6|https://market.android.com/publish/gwt/|FCCA4108CB89BFC2FEC78BA7363D4AF6|com.google.wireless.android.vending.developer.shared.MerchantService|getCurrencyExchangeRates|com.google.common.money.CurrencyCode/112449834|java.util.ArrayList/4159755760|1|2|3|4|2|5|6|5|235|6|13|5|18|5|81|5|53|5|72|5|102|5|121|5|177|5|175|5|205|5|204|5|55|5|86|-1|
The request is pipe-delimited list of tokens with the following meaning:
7 - protocol version
0 - flags. 1 is FLAG_ELIDE_TYPE_NAMES, 2 is FLAG_RPC_TOKEN_INCLUDED
6 - string token count
6 string tokens:
https://market.android.com/publish/gwt/
FCCA4108CB89BFC2FEC78BA7363D4AF6
com.google.wireless.android.vending.developer.shared.MerchantService
getCurrencyExchangeRates
com.google.common.money.CurrencyCode/112449834
java.util.ArrayList/4159755760
The actual encoded request, which references strings from the list above using 1-based indices:
1 - https://market.android.com/publish/gwt/ - base URL
2 - FCCA4108CB89BFC2FEC78BA7363D4AF6 - some hash, which is references as serializationPolicyStrongName in GWT sources.
3 - com.google.wireless.android.vending.developer.shared.MerchantService - service name
4 - getCurrencyExchangeRates - method name
2 - parameter count. Parameter types follow:
5 - com.google.common.money.CurrencyCode/112449834
6 - java.util.ArrayList/4159755760
Serialized parameters. Each object is represented either by its classname and list of serialized fields or by negative integer back-reference to previously encountered object. In our case we have two objects:
5 - com.google.common.money.CurrencyCode/112449834, which only has one integer field: 235
6 - java.util.ArrayList/4159755760, which has one integer length field 13, followed by 13 serialized list items. Note that 12 of them are CurrencyCode objects serialized just as the above one, and the last one is a backreference (-1) to the very first object we encountered while (de-)serializing this request, i.e. CurrencyCode(235)
Response format
//OK[235,3,'D0JA',2,86,3,'CXXg',2,55,3,'DW2A',2,204,3,'X9NA',2,205,3,'EuvA',2,175,3,'VIig',2,177,3,'E2Dw',2,121,3,'E4ziA',2,102,3,'do$Q',2,72,3,'T82w',2,53,3,'Ds0Q',2,81,3,'Cq5g',2,18,3,'Dlfg',2,13,1,["com.google.common.collect.RegularImmutableList/440499227","com.google.common.money.SimpleMoney/627983206","com.google.common.money.CurrencyCode/112449834"],0,7]
The response is very similar in format to the request except it's JS-formatted array (though not JSON, as it uses invalid single quotes), and it's in reverse order.
The field meaning is as follows:
7 - protocol version
0 - flags, same as for request
Array of string tokens:
com.google.common.collect.RegularImmutableList/440499227
com.google.common.money.SimpleMoney/627983206
com.google.common.money.CurrencyCode/112449834
And then goes one serialized object of type 1 - com.google.common.collect.RegularImmutableList/440499227 with one integer length field 13, followed by 13 serialized objects of class 2 - com.google.common.money.SimpleMoney/627983206. Each SimpleMoney object has two fields, for example:
'Dlfg' - long integer field encoded as base64 number. This particular one is 940000
3, 18 - CurrencyCode object with integer field 18
What you are looking at is GWT-RPC serialization format. Unfortunatelly it is not publicly documented. Fortunatelly GWT is open-source so you could look at the source to see how it is produced.
Note: This format might change between GWT versions (I known it did in 2.2). This is most likelly also a reason why Google does not document it - if they did they'd need to keep it backward compatible.
Class names that you see are Java classes that Google Checkout uses internally. When GWT is compiled to JS the names get mangled so you don't see them any more.
As noted this is GWT-RPC.
What you are trying to do is reverse-engineer Google internal APIs. I wouldn't do that because, a. It might change without notice, breaking your app and, b. I'm sure Goog wouldn't like it and it probably violates the service agreement (have you read it?).
I have some code made in VB that may be useful for you to realize how to parse GWT Serialized strings. "Datos" contains the string you received.
aAux = Split(Datos, ",[")
aAux(1) = Replace(aAux(1), "],0,7]", "")
aAux(0) = Replace(aAux(0), "//OK[", "")
aAux(0) = Replace(aAux(0), "'", "")
aDescripcion = Split(aAux(1), """,""")
aValor = Split(aAux(0), ",")
InvertirArray aValor
For X = 0 To UBound(aValor)
If Not IsNumeric(aValor(X)) Then
Exit For
End If
If adescripcion(Int(aValor(X))-1) = "gov.senasa.embalajemadera.shared.domain.Pais/3238585366" Then
For Y = X + 1 To UBound(aValor)
If Int(aValor(Y)) = "" Then '- Do what you want
end if
If adescripcion(Int(aValor(Y))) = "java.lang.Integer/3438268394" Then
'- Do what you want
Next Y
End If
Next X
Of course you have to adapt it to your needs and you will have to play a little bit with the arrays...
InvertirArray:
Public Sub InvertirArray(ByRef Arr() As String)
'- el array va tiene que empezar en 0
Dim X As Long
Dim Hasta As Long
Dim Tmp As String
If UBound(Arr) Mod 2 = 0 Then
'- Es impar
Hasta = UBound(Arr) + 1
Else
Hasta = UBound(Arr)
End If
For X = LBound(Arr) To UBound(Arr) \ 2
Tmp = Arr(X)
Arr(X) = Arr(UBound(Arr) - X)
Arr(UBound(Arr) - X) = Tmp
Next X
end sub
And of course you need to decode and encode Long Numbers and dates. So:
Public Function EncodeDateGwt(Numero As Double, Optional isDate As Boolean = False) As String
Dim s As String
Dim a As Double
Dim i As Integer
Dim u As Integer
Dim Base As String
Numero = IIf(isDate, Numero * 1000, Numero)
Base = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_$"
Do While Val(Numero) <> 0
a = Numero
i = 0
Do While a >= 64
i = i + 1
a = a / 64
Loop
If i <> u - 1 And u <> 0 Then EncodeDateGwt = EncodeDateGwt & String(u - i - 1, Left(Base, 1))
a = Int(a)
EncodeDateGwt = EncodeDateGwt + Mid(Base, a + 1, 1)
Numero = Numero - a * (64 ^ i)
u = i
Loop
EncodeDateGwt = EncodeDateGwt & String(i, Left(Base, 1))
End Function
Public Function DecodeDateGwt(Texto As String, Optional isDate As Boolean = False) As Long
Dim Base As String
Dim a As Integer
Base = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_$"
For a = 1 To Len(Texto)
DecodeDateGwt = DecodeDateGwt + (InStr(Base, Mid(Texto, a, 1)) - 1) * (Len(Base) ^ ((Len(Texto) - (a))))
Next
DecodeDateGwt = IIf(isDate, DecodeDateGwt / 1000, DecodeDateGwt)
'devuelve timestamp
End Function
If what you need to encode/decode is a date, then you need to do this before:
Call encodegwtdate(date2unix("20/02/2016"),true)
Public Function Date2Unix(ByVal vDate As Date) As Long
Date2Unix = DateDiff("s", Unix1970, vDate)
End Function
Public Function Unix2Date(vUnixDate As Long) As Date
Unix2Date = DateAdd("s", vUnixDate, Unix1970)
End Function
Hope you solve it. By the way, does anyone knows what negative numbers means?????