com.esri.core.gps
Enum FixStatus

java.lang.Object
  java.lang.Enum<FixStatus>
      com.esri.core.gps.FixStatus

All Implemented Interfaces:

Serializable, Comparable<FixStatus>

public enum FixStatus
extends Enum<FixStatus>

Fix quality of a GPS Connection based on the NMEA GPS quality indicators in a GGA string.

The fix status indicates the type of signal or technique being used by the GPS receiver to determine its' location. The fix status is important for the GPS consumer, as it indicates the quality of the signal, or the accuracy and reliability of the location being reported. The GPS receiver includes the fix status with the NMEA sentence broadcast to the Mobile SDK. For a better understanding of the GPS technology and terms please review our understanding GPS document. The fix type is determined by the receiver based on number of satellites visible, the type of GPS receiver and the GPS technology being used.

INVALID indicates that there is no satellite signal being received or there are not enough satellites available for proper location determination.

GPS_FIX indicates a standard GPS signal, or Standard Positioning Service (SPS) is being used. SPS is the standard specified level of positioning and timing accuracy that is available, without qualification or restrictions, to any user on a continuous worldwide basis. The accuracy of this service will be established by the U.S. Department of Defense based on U.S. security interests.

DIFFERENTIAL_GPS_FIX indicates that Differential GPS is being used to proved increased accuracy over SPS. This technique uses a network of fixed ground based reference stations to broadcast the difference between the positions indicated by the satellite systems and the known fixed positions. These stations broadcast the difference between the measured satellite pseudoranges and actual (internally computed) pseudoranges, and receiver stations may correct their pseudoranges by the same amount.

PRECISE_POSITIONING_SERVICE_FIX indicates that Precise Positioning System, encrypted for government use is being used by the receiver. PPS is the most accurate positioning, velocity, and timing information continuously available, worldwide, from the basic GPS. This service will be limited to authorized U.S. and allied Federal Governments; authorized foreign and military users; and eligible civil users. Unauthorized users will be denied access to PPS through the use of cryptography.

REAL_TIME_KINEMATIC (RTK) satellite navigation is a technique used in land survey based on the use of carrier phase measurements of the GPS, GLONASS and/or Galileo signals where a single reference station provides the real-time corrections of even to a centimeter level of accuracy. When referring to GPS in particular, the system is also commonly referred to as Carrier-Phase Enhancement, CPGPS. This GPS technique uses the radio signal (carrier) to refine it location initially calculated using DGPS. The receivers are able to reach this level of accuracy by performing an initialization, that requires data from at least five common satellites to initialize on-the-fly (in motion) tracking at least four common satellites after initializing.

FLOAT_REAL_TIME_KINEMATIC (Float RTK) is very similar to the fixed RTK method of calculating location, but is not as precise, typically around 20 cm to 1 meter accuracy range. This decreased accuracy is offset by increased speed, since the time consuming initialization phase is skipped.

ESTIMATED FIX or Dead reckoning is the determination of a location based on computations of position given an accurately known point of origin and measurements of speed, heading and elapsed time. Dead reckoning coupled with GPS positioning provides a powerful navigation solution. GPS positioning provides highly accurate "points of origin" when exposed to sufficient satellite signal strengths during a trip. Dead reckoning can be used to "fill in the gaps" when there are insufficient GPS signal strength to obtain an accurate position.

MANUAL_INPUT_MODE indicates that the location has been manually entered into the GPS receiver, and is not based on the satellite system. This type of fix is useful for entering the coordinates of a known location, that has been previously measured. In this type of GPS fix the location has been input directly into the GPS receiver, which then reports that to the GSPconnection as a NMEA Sentence. If you are manually entering a coordinate location into a ArcGIS Mobile application, you would typically go directly into the GIS database and not though the GPS receiver.

SIMULATION_MODE This mode is not always called simulation mode on the different models. On the some models it is called "demo mode" or "gps off" while others call it "Use Indoors" or "gps off". Upon entering simulation mode you will find that the gps seems to have a lock on satellites and everything works similarly to the way it works when you actually have a fix. The satellite status page shows that you have a lock on the satellite graphic display and indicates that you are in Simulation mode in the status text field. The rest of the fields in the unit do not how that you are in simulation mode but may have extra commands or other information and may perform differently. For example, the units with object oriented commands add selection capability for speed and track settings so that you can change them on any screen at any time to permit simulating actual movement while using the gps. Menu oriented units set this information on the original simulation mode setup screen so if you wish to change it you need to revisit the setup screen.

One of the uses of simulation mode is to allow for route and waypoint maintenance. While you can perform maintenance on a unit that is trying to track satellites you may get "poor gps coverage" because you are using it indoors or other annoying messages. Setting simulation mode avoids these messages and as a bonus saves about 1/2 on the battery consumption since in this mode all of the power is removed from the receiver circuitry.

Enum Constant Summary

DIFFERENTIAL_GPS_FIX

ESTIMATED

FLOAT_REAL_TIME_KINEMATIC

GPS_FIX

INVALID

MANUAL_INPUT_MODE

PRECISE_POSITIONING_SERVICE_FIX

REAL_TIME_KINEMATIC

SIMULATION_MODE

Method Summary

static FixStatus	getFromCode(String code)
static FixStatus	valueOf(String name) Returns the enum constant of this type with the specified name.
static FixStatus[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

INVALID

public static final FixStatus INVALID

GPS_FIX

public static final FixStatus GPS_FIX

DIFFERENTIAL_GPS_FIX

public static final FixStatus DIFFERENTIAL_GPS_FIX

PRECISE_POSITIONING_SERVICE_FIX

public static final FixStatus PRECISE_POSITIONING_SERVICE_FIX

REAL_TIME_KINEMATIC

public static final FixStatus REAL_TIME_KINEMATIC

FLOAT_REAL_TIME_KINEMATIC

public static final FixStatus FLOAT_REAL_TIME_KINEMATIC

ESTIMATED

public static final FixStatus ESTIMATED

MANUAL_INPUT_MODE

public static final FixStatus MANUAL_INPUT_MODE

SIMULATION_MODE

public static final FixStatus SIMULATION_MODE

Method Detail

values

public static FixStatus[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (FixStatus c : FixStatus.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static FixStatus valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

getFromCode

public static FixStatus getFromCode(String code)