Search result for:  id10=WA 0852 2611 9277 [[GLORION]] Jasa Pasang Lemari Dapur Second di Indigo Apartment Bekasi

If you're exporting data from G-864, MagArrow, or MagEx, using any of the export tools - Quick Conversion, Command-line conversion, or export from a project and survey in Survey Manager - and you don't get any data, or you think the export is missing some data, follow these steps: Verify that you have records to export: In survey manager, verify that the survey has data in it: there's a "Measurements" field in the survey details. For MagArrow, if you're using Quick Conversion or the command line program, you will need to create a project and survey in Survey Manager and import the .magdata file into it. If you don't have any data records, then verify that you've opened the correct file. If you have records, but they just don't seem to be exporting, then choose to export invalid records and records without locations The export functions in Survey Manager allow you to choose this option with the "Filter" choices: Look in the exported file for records without locations (no GPS) and with invalid records; they are not included in the default exports. For MagArrow, export with 1000 samples/second. If you are troubleshooting an export at a decimated rate (e.g. 20 samples/second) then note that a single invalid record in the 1000 samples/second original data may invalidate about 1/2 Second of data; in a 20 samples/second MagArrow decimation, a single 1000 samples/second invalid record will invalidate about 10 decimated results.

The time associated with each data point in a SEG-2 data file generated by a Geode is related to the time of the “trigger” event which was instrumental in the production of the file and its content. The Trigger Master and Trigger distribution The trigger event occurs at the Geode designated within the Controller software as the Trigger Master. Although all Geodes are capable of being Trigger Masters, there must be one and only one Trigger Master in any properly functioning Geode system. The Controller automatically takes care of this requirement when the designation is made by a user, and when the system is established at the time of Controller start-up based on a previous designation (or a default setting in the case of a “new survey”). All other Geodes in the system will have their Trigger Master circuit disabled. A trigger event can be initiated by an external electrical pulse provided to the trigger input connector of the Trigger Master Geode, or by a command sent via Ethernet from the Controller to the Trigger Master (usually for test purposes), but only when all conditions are satisfied to allow data recording. There is also a special trigger initiation situation, called “self-triggering” which will not be discussed further here. Upon acceptance of a trigger event, the Trigger Master will distribute the trigger signal to all Geodes in the system, itself included, via an RS-485 network that resides within the digital interconnect cabling. (Proper termination of this RS-485 network is automatically taken care of by the Controller.) The trigger signal is propagated through the cabling and Geodes at the nominal speed of 70% of the speed of light, or approximately 2.1x10^8 m/sec. The maximum distance of successful propagation depends on a number of factors such as the number of Geodes involved, the noise environment, the quality of the cables, and the acceptable amount of timing uncertainty for the particular application. distances approaching or exceeding 1km should be given careful attention in this regard. In a 3-D Geode system involving LTUs, each LTU, unlike a Geode, will reconstruct the trigger signal before sending it on, effectively confining the maximum distance issue to each sub-network separated by LTUs. The penalty is an additional delay of about 100nS for each LTU in the route. The External Trigger Circuit The external trigger input is capacitively coupled, with a 2mS time constant, to the midpoint of a resistive voltage divider. The voltage difference between the two ends of the divider constitute a voltage "window", which size is set by the trigger sensitivity parameter and can range from essentially zero at the highest sensitivity, to about +/- 2.5V at the lowest sensitivity. The Geode will trigger (if enabled) if and when the coupled signal exceeds the window, in either direction (i.e., positive or negative going). The signal, after the capacitor, is clamped by diodes to the range between the trigger signal ground and +5VDC. The trigger detector output is disabled when the system is disarmed, during a parameter change, and during a shot, up to the trigger hold-off time after the end of the shot. The trigger hold-off time is a parameter set by the user. Preceding the coupling capacitor (i.e., essentially the node accessible at pin A of the external connector), there is a 3.3K-Ohm pull-up resistor to +5VDC (relative to pin B). Also a fast transient suppressor clamps the input at about +/-14VDC. It is advised that the DC + AC level of any voltage applied to pin A relative to pin B be kept within the range of +/-7V, giving some margin of safety. If a DC voltage somewhat less than +5VDC is applied when the connector is first mated, the instrument may trigger at that moment. But, subsequently, because of the capacitive coupling, it will trigger on the next positive or negative going pulse that exceeds the window level. If the duration of the applied voltage pulse is less than the record length + delay time + hold-off time, then the Geode will effectively be ready to trigger on the same edge of another similar pulse. Sub-sample Synchronization The Geode supports a sub-sample timing synchronization feature used for synchronizing the data acquisition after a trigger event to the distributed trigger signal, so that subsequent time points will be known to within 1/32 (~1/20 at the fastest two sampling rates) sample interval. It does this by increasing the sample interval at the trigger time by 0 to 31/32 of a sample interval in increments of 1/32, so that the first sample after the trigger would represent a time of one sample interval after the trigger event, with a tolerance within 1/32 of a sample interval. The following samples continue from there at the expected intervals. For example, with a selected sampling interval of ¼ mS and a recording delay of 0mS, the first sample in the recorded file for each channel would represent data at 250 to 258uS after the trigger event. This of course potentially introduces a small discontinuity at the time of the trigger, observable depending on the nature of the channel waveform(s). (The zero-phase anti-alias filter will smear the discontinuity into the nearby samples both before and after, consistent with the bandwidth of the filter.) Sub-sample synchronization can be disabled if it is deemed to be detrimental for the particular application, at the expense of losing the 1/32 interval timing accuracy. Timing Errors The principal errors in Geode timing are of two types: those associated with the trigger mechanism and which are static over the duration of the record, and those associated with the time base and which change over the duration of the record. Excluding the trigger propagation delay mentioned above, the trigger timing uncertainty is about 1uS. The known fixed errors have been lumped together and are reported in the SEG-2 file trace headers as channel SKEW. (The actual channel skew is zero, since all channels are effectively sampled simultaneously, but the SKEW value in the header is used as the only place permitting small timing corrections. Note that the SKEW value for every channel is identical.) If the size of this correction is important to the application, the SKEW value should be added to the calculated time points when the data is being processed. The Geode time base has a +/-15ppm stability over temperature (-20C to +70C) and component variations. Thus time drift relative to absolute time and relative to other Geodes is possible. (However, all channels within any Geode enclosure use the same time base, so there is no relative drift between channels in the same enclosure.) Therefore timing uncertainty increases from that existing at the time of the trigger until the time of the next trigger (or end of record). Special Timing Issues Involved with “Continuous” Recording “Continuous” recording is a method that allows unending 100% time coverage with recorded Geode data. It produces a series of time-overlapped records created by the use of a negative time delay set equal to the record length such that each record consists of completed history at the time of the trigger event. This technique circumvents the problem of data transmission overrunning data acquisition. The principle constraint is that the cycle time from trigger to trigger must always be less than the chosen record length. Otherwise, gaps rather than overlap would result. Commonly it is used with GPSderived triggering in order to provide time-stamping of each trigger event. Upon consideration of the above, it will become clear that the time-stamp associated with a particular trigger event will pertain to the data in the following record, not to the data in the record in which the time-stamp is written. This comes about because the trigger event ends the record. Because there is data overlap between records, the precise trigger point in the following record at which the time-stamp applies can be found by comparison of the data values at the end of the former record with those near the beginning of the subsequent record. The overlapping data will be exactly identical in both records (since they are read from the same memory location, twice). The earliest data in the subsequent record that goes beyond the data of the previous record is the data that is one sample interval (assuming sub-sample synchronization is enabled) past the time-stamp. Note well that this comparison must be made independently for at least one channel of each 8-channel Geode board set, because the discrete time at which data values are written to the memory buffer, relative to the trigger event, is a function of each individual board set in the Geode system. Correct GPS Time-Stamping There are differences between various GPS models that can affect accurate time stamping. The 1PPS signal from a GPS has a “timing edge” and return edge, of which only the former is the true whole-second edge. Some models use a rising edge as the timing edge, some the falling edge, and some have it selectable. Consult the GPS manual to determine the definition of its timing edge. As indicated earlier, the Geode can be triggered on either a rising or falling edge. It is important to insure that the Geode is being triggered on the proper edge in order to avoid timing that may be a fraction of a Second off. This is expanded upon below. Some GPS units provide a very narrow timing pulse, others one that has a nearly 50/50 duty cycle. For the narrow pulse units, almost certainly it is the leading edge (rising or falling) that is the “timing edge”. This case can be easily handled by using the Geode Trigger Hold-off feature. If a 10-second cycle time is desired, set the Trigger Hold-off time to about 9.5 Seconds. In this case, there is a very small chance that the very first trigger could occur on the wrong (trailing) edge, but from then on the leading edge will be used as the triggering edge. If the GPS provides a 50/50 duty cycle edge, and it is not alterable, then the Geode by itself could as easily start on the wrong edge as on the correct timing edge, and continue thusly until restarted. For this case, Geometrics can provide a Trigger Timing Interface Box (TTIB) that will correct the situation. The TTIB can be programmed to respond only to the correct edge (rising or falling), change the polarity if needed, and gate through only one of every N 1PPS pulses, where N is programmable. (The TTIB also incorporates an alarm system that can provide a remote alert if a record is missed.) Another potential issue comes from the variations between GPS models of the time that the serial time string (containing the time value of the associated 1PPS) is issued relative to the 1PPS itself. The Geode Controller attempts to pick the correct serial string based on a calculation involving the known record length, the PC times, and the trigger notification message from the Geodes. But if the GPS issues the serial string at an unusual time (and the time has been seen to vary somewhat with a given GPS unit) then it could pick up the incorrect time, off by 1 Second. If rare, it can be subsequently detected and corrected during data processing, but if consistent it may not be easily detected. Again, the TTIB can accommodate the situation by only gating through to the Controller PC the string belonging to the gated-through 1PPS pulse. The Controller Serial Input Time Window can then safely be widened to 2 Seconds (assuming the cycle time is more than 2 Seconds) if need be, to expand the Controller’s search for the string around the calculated trigger time.

1. When the transmitter is turned on, the red power light (or green light in later versions) comes on and stays on. The blue light will go into a rapid flashing pattern then settles into a three-flash sequence, for example short-long-short or short-long-long, or something like that. Is that what the transmitter is doing? If not, there are three possible causes of the problem and this will require require swapping parts: Defective dipole cable or shorting plugs are two potential problems. The best test is to plug the shorting plugs directly into both ends of the Transmitter and turn on. If this works, then add one dipole cable and turn on again. Then add the Second cable and power up. If failure occurs with just the shorting plugs then the most likely problem is a battery with a shorted internal cell. This will look like it is fully charged when you measure it with a volt meter, but will not be able to supply the current required to drive the transmitter. Swap out batteries to test. If swapping the batteries does not resolve the issue and you never get the blue light to start flashing you may have a bad Tx and it would need to be returned to Geometrics. 2. When the receiver is turned on the red power light will come on, then the blue light will flash rapidly, then the blue light will turn off waiting for the receiver to phase lock onto the Tx. Once it locks onto the transmitter the blue light will start flashing at once per measurement. Depending on how conductive the ground is and how far apart the Tx/Rx separation is you may have to wait up to a minute to get the lock. Try it with about a 5 meter separation between the end of the dipoles, i.e. the equivalent to having a 5-meter rope between them. The Rx should lock and start flashing within about 20 Seconds. If it never locks on even though the Tx's blue light is flashing then there may be something wrong with the receiver and it would need to be sent back. Remember that the transmitter blue light has to be flashing first. If the Tx is not working the Rx will never detect it and start flashing. 3. With the Rx turned on, even if the blue light is not flashing, when you look at the OhmMapper Test screen on the console do you see the message: Setting Gain, Phase A, Phase B or something similar being updated on the screen every Second (or twice per Second with the old systems)? If so your console is communicating with the receiver. If not, you have no communication between the Rx and the console so you could have a bad dipole cable, bad optical wand, bad console cable, or a bad receiver. If you have spares of any of these items you can troubleshoot the problem. If you have no spares then you will need to send the system back here for evaluation by submitting an RMA request.

________Install 4ea new AA battery. ________Install dummy blasting cap to “CAP” of HVB. Make sure a wire touch the pencil lead. See attached picture. Connect the Bendix trigger connector to the Seismograph. Press “ARM” button (and keep pressing “ARM” button thru all test finished) and observe LED on the “READY”. It takes around 1-2 Second after pressing “ARM”. _____________”READY” LED on around 1-2 Second after pressing “ARM” switch. Make sure wearing safety glasses to protect your eyes for next test. _____________Wear safety glasses. Press “FIRE” button while pressing “ARM” switch. Observe dummy led cap sparks and “READY” LED off, and trigger the Seismic unit. _____________Dummy led blasting cap sparks ______________”READY” LED off. ______________Trigger the Seismic unit After firing the cap, “READY” LED lit on again within 5 Seconds later ______________Within 5 Seconds after firing, the “READY” LED on again. Pressing “FIRE” again. You may adjust dummy led blasting cap to see sparks. ______________Fire works again. ______________Trigger works again Continue firing HVB 5 times. ______________It works 5 times.

I have set up a G-882 system here at Geometrics and am receiving data and sending commands using TeraTerm (any terminal emulation program should work). When in normal use mode the digital add on board sits in front of the G-882 and parses and acts on all commands coming in. There are two versions of the digital Add On board, which are the GP120 and the GP140. The GP140 is a newer version of the digital Add ON board. It is the GP140 digital board that outputs all S/N (and other) information. I first set up with the GP140 board (the newer version). I find that the ""RESET" command does work - i.e. it goes into BYPASS mode for a couple Seconds, then output the S/N and configuration information, and reverts to normal operation with the digital depth and altimeter information. But it only works every other time I send it. The first time nothing happens. Then I send it again and it works. This appears to be a bug in the GP140. For some commands the first command after power up or reset are ignored. The Second time (and subsequent commands) are executed. The work around seems to be sending the RESET command twice. I also tried an older G-882 with the GP120 digital board. The Reset (and other commands worked first time and every time. BTW, the digital Board version is in the Second line with the S/N information that is sent on power up or Reset. Some questions: 1) My configuration is one G-882 connected to a PC through the white junction box. Is this your configuration, or do you have concatenated G-882's? 2) Can you get the G-882 to accept any commands (like going into Bypass Mode)? I'm wondering if there is a open link in the command line from the PC to the digital board.

The Geometrics magnetometer softwares check for some uncommon anomalies in GNSS location and timing messages in data collected with the G-864, MagEx, and MagArrow instruments. These anomalies have occurred in data from a few instruments: Extra PPS timing signals – Sometimes the PPS sensor in the instrument receives an extra timing signal that’s out of phase with the normal 1-second interval. These are almost always easily identified and discarded. GNSS timing anomalies – Very rarely, the GNSS appears to change its mind about the current time or location. For example, after recording a time at 06:30:21, the next measurement – received one Second later – might show a time of 6:30:15 – 16 Seconds earlier. GNSS location anomalies – A GNSS timing jump may be accompanied by a location jump. Geometrics’ software now makes additional checks for these anomalies, corrects them when possible, and reports them if they affect the use or visualization of the data. Some of the checking is in the instruments, some in MagNav, and some in Survey Manager. Users will notice these anomalies and the functionality to repair and report them in these ways: During import or export, the software identifies an anomaly. If it’s judged to be worth reporting – most likely because it affects the reported locations of magnetometer readings – then it is logged and the user asked to review the log file. The user exports data and notices something unusual, for example a discontinuity in the GNSS times or locations. The customer should review the software’s log files for additional information. These anomalies are unusual; the type where the GPS changes its mind about the time or location is exceedingly rare and will never be seen by most customers. The main effect of the new functionality is that the data validation process will now be more visible to users.

The 1PPS pulse phase locks and synchronizes the sample interval to be in lock step with the GPS. Thus once locked there will always be 1000 samples per Second, with the sample beginning time precisely lined up with the 1 PPS edge. The 10 MHz input is for a different function. This input phase locks the 40 MHz master reference oscillator to the incoming 10 MHz, which is usually a GPS disciplined reference oscillator or atomic clock (in other words exactly 10 MHz). This phase locks the 40 MHz reference oscillator to exactly 40 MHz. The 40 MHz oscillator is the time base reference for calculating the Larmor frequency, and therefor the magnetic field value. Even though the 40MHz oscillator is really good even without the 10 MHz input, there is some drift in the 40 MHz over time (mostly thermal drift and some aging). For some applications where they need to measure very low frequency and low amplitude changes in the magnetic field the 10 MHz input will allow drifts in the reference oscillator to be removed. Without that it would be impossible to distinguish between reference oscillator drifts and low frequency low amplitude changes in the magnetic field. The connector for the 10 MHz input is SMB RF connector from Molex. If you must simulate the 1 PPS signal in a GPS denied environment, please be aware of certain requirements of the 1 PPS signal. 1. The lock range for the 1 PPS input pulse is very narrow. The simulated 1 PPS signal must be within 100 ppm of an exact 1 Hz PPS signal (100us). 2. Timing jitter must be small (less than 0.5 ppm, 0.5us) too. If you are setting a GPIO pin on a microcontroller, there may be some concern about timing jitter due to interrupt latency or other processor tasks delaying the I/O pin toggle. Any rectangular waveform should work but the leading edge must be very close to 1 Hertz. It is the positive edge that specifies the 1 Second rollover.

Regarding the deployment of magnetometers on conductive sleds or carts near power lines: Depending on the proximity of the magnetometer to the sled, elevated field readings may be observe under power lines are a result of AC induction in the aluminum sledge you are using as the tow vehicle. The reason there can be a DC effect from an AC source is due to 1) the strength and proximity of the induced AC source and 2) the orientation of the induced AC field relative to the Earth's field (DC). Our cesium-vapor magnetometers measure the total local field continuously but report these measurements periodically, e.g at 10, 1000 times per Second. For each reporting period, both the AC and DC components of the total field are integrated to produce the measurement result as a time average over the measurement cycle. If your measurements are being reported 10 times per Second (10 hz sample rate) and the AC component of the field is 50 hz, then each measurement will include exactly 5 AC cycles. This AC component will add to the DC component as a vector sum and the magnetometer will measure the magnitude of the resultant vector. Note that the vector component of the 50 hz AC field that is parallel to the DC component will not contribute to measurement results: for half of each AC cycle this field is greater than the DC field and for the other half of the cycle it is less than the DC field by an equal value. This is not the case for the AC vector component that is perpendicular to the DC field: it will be adding magnitude to the DC field on each 1/2 cycle to produce a half-wave-rectified wave form. Specifically, this rectified field will add to the DC field by an amount equal to about 35% of its peak-to-peak field strength in the direction perpendicular to the DC component. The AC rectification described above is only seen on close approach to very strong AC sources (high tension power lines). An aluminum sled can act as an indirect source of the AC fields: the radiated 50 hz field from the power lines is inducing 50 hz eddy currents in the sled and, if a magnetometer is in close proximity of the sled's aluminum plates, it will detect large AC field values. Note that surveying near other large, planar conductors under the high tension power line can produce a similar effect. These would include metal buildings, metal fences, and pipelines. We recommend constructing magnetometer sleds from non-conductive materials. If this is cannot be done, then conducive materials should be kept as far from the sensor as is practical and the sled's construction should not include sheets of conductive materials. Any joints between conductive structural elements should be insulated as well. You can use the magnetometer itself to measure the effect of the sled.

Raw Data MagArrow data is imported into Survey Manager in the form of .MAGDATA files, downloaded from the MagArrow. The .MAGDATA file contains measurements from different sensors inside the MagArrow: 1000Hz magnetometer readings; accelerometer, gyro, compass, temperature readings; and GPS info. MFAM assigns a fiducial number, or “FID” to each magnetometer reading, in a cycle from 1 to 1000 that repeats every Second. In the instrument, the magnetometer readings and the GPS sentence data are synchronized so that the “FID-1” magnetometer record is matched with the GPS location and timing information. Exports to CSV and Geosoft file formats 1000Hz un-filtered export The 1000Hz export provides the original raw magnetometer data plus some simple interpolations: • Magnetometer reading: The raw magnetic field values are exported without application of a filter. [While these raw measurements are the output of a filter inside the MFAM sensor: a 9-pole Butterworth low pass filter with a -3dB point at 400Hz, that filter is considered part of the sensor for this description.] • Auxiliary sensors: Gyro, accelerometer, and temperature are acquired once per every 5 magnetometer readings, and are reported only when acquired. Compass readings are acquired one per every 10 magnetometer readings and are reported only when acquired. • GPS NMEA sentence: Reported with the associated FID-1 mag record. A few individual fields from the GPS are also broken out from the GPS sentence and reported separately, without interpolation. • Interpolated GPS fields: Time, date, latitude, longitude, and track (course over ground) are linearly interpolated between GPS readings. Decimated exports Each of the exports at frequencies from 10 Hz to 100 Hz is a decimation – data are filtered by a low-pass filter and then down-sampled to the target sample rate. Each low-pass filter (a different one for each decimation) is a symmetric finite impulse response (or FIR) filter, with the following design goals: • -3dB attenuation at 0.75 * Nyquist frequency (e.g., the -3dB point for the 10Hz decimation is 3.75Hz) • Significant attenuation of 50Hz and 60Hz signals. • Reasonably flat response in the pass band. Linear phase (or zero phase, or constant group delay) filters. These filters are not Kalman filters. The filters are applied to fields in the decimations as follows: • Magnetometer readings: Magnetometer readings are decimated: the FIR is applied, then the data are down-sampled to the target rate. • Aux sensors: Aux sensors are first up-sampled to 1000Hz by linear interpolation of values between individual readings (which occur once every 5 mag readings for gyro, accelerometer, and temperature, and once every 10 mag readings for compass). Then these 1000Hz values are decimated in the same process as the magnetometer readings. • Latitude and longitude are first up-sampled to 1000Hz by linear interpolation of values between successive GPS data (once per Second), then these 1000 Hz values are decimated in the same process as the magnetometer readings. • Time, date, and track are linearly interpolated as in the raw, unfiltered 1000Hz export. Merging filtered and unfiltered data. Some of the values in an individual line of data are filtered: mag readings, aux sensors, etc. Other measurements are not filtered: time and date, GPS sentences, record counters, and the simple interpolated fields. These two sets of values – filtered and unfiltered, must be reported in individual lines that contain values of both types. The question “How should the two sets of values be matched?” is addressed as follows: A decimation filter has a center. For example, a single filter result that weighs 499 individual measurements running from record number 752 to record number 1250 (in DSP terms, it is the result of the convolution of 499 input values with 499 filter weights), is centered on record number 1001. The result is the “filtered value of record 1001”. In a single line along with this value should be the other filtered results centered on record number 1001 plus the unfiltered raw and interpolated values that were recorded as part of the original, raw record 1001. The down-sampling part of decimation involves keeping some results and discarding others; down-sampling from 1000Hz to 100Hz includes discarding 9 out of 10 results. During exports, Survey Manager keeps the “FID 1” record, because it includes the original GPS information, then discards the next 9 records (if it’s a 100Hz decimation), and then repeats the pattern, each time starting with FID 1. If you have questions about the MagArrow decimations, please contact your Geometrics account manager.

Hello, I saw in a previous post that the current firmware only supports MFAM streaming via Ethernet, and that UART5 isn't supported. I'm modifying the Dev Kit firmware to add TX output on UART4 instead, by adding a parallel Mailbox_post in spiTaskFxns.c to a new UART4 TX task/mailbox, at 460800 bps. Before going further, I wanted to ask: Is there any hardware-level reason UART4 wouldn't work here, beyond it just not being implemented in the stock firmware? Does the existing SPI→Ethernet pipeline assume a single consumer, in a way that could cause timing issues if I add a Second parallel mailbox post for UART4? Has anyone tried UART-based streaming from the Dev Kit before, and if so, any known pitfalls? Thanks in advance!

Customer had problem connecting Wi-Fi using domain magarrow.net. Solution: Verify the blinking LED patterns are ok: 1) One steady blink and a pause, about once per Second - The MagArrow is ready for a WIFI connection from your device. 2) Two short blinks followed by a pause – A device is connected to the MagArrow’s WIFI. If your device or another nearby device is set to connect automatically, this two-blink pattern might commence quite soon after power-on. If the MagArrow LED blinks normally, please try to connect to 192.168.1.1, instead of magarrow.net. If the LEDs don’t blink in these patterns, refer to the user manual’s troubleshooting section and/or contact support@geometrics.com

The Earth's magnetic field changes throughout the day due to solar wind and other factors. A base station's data is used to correct for these variations (diurnal variations), which can significantly impact the results of a survey. In general, diurnal variations do not change rapidly, and it is not required to record the Earth's magnetic field at high sample rates. However, during geomagnetic storms, diurnal variations can be so rapid that 10Hz or a higher sample rate is necessary to track the field change. Kp index is commonly used to measure the strength of geomagnetic activity. The diurnal variation on October 11th 2024, when the Kp index reached above 8, was shown in the plot below. Field changes as fast as 5nT/second were recorded. In comparison, the Kp index on October 15th was around 4. The diurnal variation was much slower. Sometimes if a survey site is close to man-made structures, such as railways, very rapid local magnetic field variations can also occur due to electrical current activities. A high sample rate magnetometer base station is also required in these situations, as well as some expertise in setting up the base station.

Every Second, the NMEA strings, delimited by single quotation marks, are included as separate columns. The strings also contains commas. Therefore, there will be more columns if you use comma as the only delimiter. The correct import setting should be comma-separated, with single quotation marks as string delimiters. All of those "extra" columns will be revealed as the original RMC and GGA NMEA strings.

1. Make sure the tablet is connected to the instrument via WiFi. 2. The correct connecting sequence is as following: If you start MagNav, and then connect WiFi to the instrument, or if you connect WiFi to the instrument and then start MagNav, then you should receive data in MagNav. If you do anything to disconnect the WiFi, for example by rebooting the instrument, or by walking out of WiFi range, or by using the tablet settings to disconnect WiFi from the instrument, then you will not be able to see data in that original open MagNav session, even if you reconnect to WiFi. The app will not communicate to the instrument through this Second WiFi connection. The solution is simple: close MagNav and then re-open it. MagNav will now communicate with the instrument (as long as the WiFi is connected). 3. This is a common feature in MagNav, which applies to all other MagNav products, such as G-864.

I was doing a survey, and the tablet lost connection with the sensor, with no data being saved to the tablet. So I took the SD card of the sensor box, hoping that the data was kept there at least as a backup before the survey ended and data was completely transferred to the tablet. But there is nothing on the SD card. It is empty instead of having a LOST.DIR folder that is also empty.So, my question is, what is the sensor box SD card for?Second, is there a way to prevent tablet disconnection from the sensor WIFI (which happens frequently) and backup data when this happens?